describe the structure and function of biological molecules;

This experiment requires your lab kit.You will explore the basic properties of the chemistry that underlies biology. You will determine the presence of biological macromolecules such as proteins and carbohydrates using reagents that change color in their presence.Additional Materials needed for the labs (not included in lab kit)Experiment 1: egg white, potato, onion, hot water,fork, knife, hot water bath, tap waterPhotos of the results of all the tests in this experiment are required. Please include within the pictures an index card with your name and date.We discussed last week that the properties of living organisms are determined by the properties of their building blocks. These building blocks interact through chemical bonding, and then form even larger entities. The elements most frequently found in biological molecules include carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, and a few others in smaller amounts. The chemistry of the element carbon is particularly important for the formation of “organic molecules” that form the basic structure of biological molecules.Biological molecules can be very large in comparison to atoms or subatomic molecules and are referred to as biological macromolecules (macro means “big”). Learning about macromolecules is important to understanding living organisms. All living organisms are characterized by the presence of four major classes of macromolecules: proteins, carbohydrates, lipids, and nucleic acids. These macromolecules are often called the molecules of life.Biological macromolecules such as proteins are able to carry out specific functions in living organisms. For example, certain proteins such as enzymes act as catalysts—substances that increase the rate of a chemical reaction between other molecules but do not change chemically themselves. These enzymes activate reactions occurring within living organisms.However, enzymes and other biological molecules made of matter do not possess the properties of life. Only after we combine these molecular building blocks to form a cell can we finally see the emergent property of life. At this point we have the smallest units of structure and function in biology: cells are then living entities.Types of cells differ considerably in their structure, size, shape, and function. Scientists usually categorize cells based on their structural features. You will learn these classifications and understand how those different features affect the cell’s purpose and abilities. Some living organisms, including humans, are composed of many different cell types among trillions of cells. Other living organisms, such as bacteria, are composed of just one single cell.In this section, we will discuss cell theory and the various organelles of a cell. We will then learn about a cell structure called the plasma membrane and see how materials move in and out of this membrane.You will participate in a class discussion related to topics in biology.You will also complete a laboratory experiment related to biological macromolecules.And you will demonstrate your knowledge of course concepts with a quiz.Week 2 OutcomesBy the end of this week, you should be able todescribe the structure and function of biological molecules;explain cell theory, the role of cells, and methods of studying cell structure;compare and contrast eukaryotic and prokaryotic cells;compare and contrast animal and plant cells;describe the structure and functions of the major cell organelles, as well as the cytoskeleton and extracellular matrix;explain the fluid mosaic model of membranes and the processes of cellular transport in eukaryotic cells;determine the presence of proteins, glucose, starch (carbohydrate) using indicator solutions;manipulate test tubes and measure liquids;measure pH (acidity) using pH strips; andapply concepts and/or argue a position related to a scientific topic.Chemistry of Life: Biological MoleculesBiological MoleculesBy the end of this section, you will be able to:describe the ways in which carbon is critical to lifeexplain the impact of slight changes in amino acids on organismsdescribe the four major types of biological moleculesunderstand the functions of the four major types of molecules.The large molecules necessary for life that are built from smaller organic molecules are called biological macromolecules. There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids), and each is an important component of the cell and performs a wide array of functions. Combined, these molecules make up the majority of a cell’s mass. Biological macromolecules are organic, meaning that they contain carbon. In addition, they may contain hydrogen, oxygen, nitrogen, phosphorus, sulfur, and additional minor elements.CarbonIt is often said that life is “carbon-based.” This means that carbon atoms, bonded to other carbon atoms or other elements, form the fundamental components of many, if not most, of the molecules found uniquely in living things. Other elements play important roles in biological molecules, but carbon certainly qualifies as the “foundation” element for molecules in living things. It is the bonding properties of carbon atoms that are responsible for its important role.Carbon BondingCarbon contains four electrons in its outer shell. Therefore, it can form four covalent bonds with other atoms or molecules. The simplest organic carbon molecule is methane (CH4), in which four hydrogen atoms bind to a carbon atom (Figure 13).However, structures that are more complex are made using carbon. Any of the hydrogen atoms could be replaced with another carbon atom covalently bonded to the first carbon atom. In this way, long and branching chains of carbon compounds can be made (Figure 14a). The carbon atoms may bond with atoms of other elements, such as nitrogen, oxygen, and phosphorus (Figure 14b). The molecules may also form rings, which themselves can link with other rings (Figure 14c). This diversity of molecular forms accounts for the diversity of functions of the biological macromolecules and is based to a large degree on the ability of carbon to form multiple bonds with itself and other atoms.CarbohydratesCarbohydrates are macromolecules with which most consumers are somewhat familiar. To lose weight, some individuals adhere to “low-carb” diets. Athletes, in contrast, often “carb-load” before important competitions to ensure that they have sufficient energy to compete at a high level. Carbohydrates are, in fact, an essential part of our diet; grains, fruits, and vegetables are all natural sources of carbohydrates. Carbohydrates provide energy to the body, particularly through glucose, a simple sugar. Carbohydrates also have other important functions in humans, animals, and plants.Carbohydrates can be represented by the formula (CH2O)n, where n is the number of carbon atoms in the molecule. In other words, the ratio of carbon to hydrogen to oxygen is 1:2:1 in carbohydrate molecules. Carbohydrates are classified into three subtypes: monosaccharides, disaccharides, and polysaccharides.Monosaccharides (mono- = “one”; sacchar- = “sweet”) are simple sugars, the most common of which is glucose. In monosaccharides, the number of carbon atoms usually ranges from three to six. Most monosaccharide names end with the suffix -ose. Depending on the number of carbon atoms in the sugar, they may be known as trioses (three carbon atoms), pentoses (five carbon atoms), and hexoses (six carbon atoms).Monosaccharides may exist as a linear chain or as ring-shaped molecules; in aqueous solutions, they are usually found in the ring form.The chemical formula for glucose is C6H12O6. In most living species, glucose is an important source of energy. During cellular respiration, energy is released from glucose, and that energy is used to help make adenosine triphosphate (ATP). Plants synthesize glucose using carbon dioxide and water by the process of photosynthesis, and the glucose, in turn, is used for the energy requirements of the plant. The excess synthesized glucose is often stored as starch that is broken down by other organisms that feed on plants.Galactose (part of lactose, or milk sugar) and fructose (found in fruit) are other common monosaccharides. Although glucose, galactose, and fructose all have the same chemical formula (C6H12O6), they differ structurally and chemically (and are known as isomers) because of differing arrangements of atoms in the carbon chain (Figure 15).Disaccharides (di- = “two”) form when two monosaccharides undergo a dehydration reaction (a reaction in which the removal of a water molecule occurs). During this process, the hydroxyl group (?OH) of one monosaccharide combines with a hydrogen atom of another monosaccharide, releasing a molecule of water (H2O) and forming a covalent bond between atoms in the two sugar molecules.Common disaccharides include lactose, maltose, and sucrose. Lactose is a disaccharide consisting of the monomers glucose and galactose. It is found naturally in milk. Maltose, or malt sugar, is a disaccharide formed from a dehydration reaction between two glucose molecules. The most common disaccharide is sucrose, or table sugar, which is composed of the monomers glucose and fructose.A long chain of monosaccharides linked by covalent bonds is known as a polysaccharide (poly- = “many”). The chain may be branched or unbranched, and it may contain different types of monosaccharides. Polysaccharides may be very large molecules. Starch, glycogen, cellulose, and chitin are examples of polysaccharides.Starch is the stored form of sugars in plants and is made up of amylose and amylopectin (both polymers of glucose). Plants are able to synthesize glucose, and the excess glucose is stored as starch in different plant parts, including roots and seeds. The starch that is consumed by animals is broken down into smaller molecules, such as glucose. The cells can then absorb the glucose.Glycogen is the storage form of glucose in humans and other vertebrates and is made up of monomers of glucose. Glycogen is the animal equivalent of starch and is a highly branched molecule usually stored in liver and muscle cells. Whenever glucose levels decrease, glycogen is broken down to release glucose.Cellulose is one of the most abundant natural biopolymers. The cell walls of plants are mostly made of cellulose, which provides structural support to the cell. Wood and paper are mostly cellulosic in nature. Cellulose is made up of glucose monomers that are linked by bonds between particular carbon atoms in the glucose molecule.Every other glucose monomer in cellulose is flipped over and packed tightly as extended long chains. This gives cellulose its rigidity and high tensile strength—which is so important to plant cells. Cellulose passing through our digestive system is called dietary fiber. While the glucose-glucose bonds in cellulose cannot be broken down by human digestive enzymes, herbivores such as cows, buffalos, and horses are able to digest grass that is rich in cellulose and use it as a food source. In these animals, certain species of bacteria reside in the digestive system and secrete the enzyme cellulase. Cellulases can break down cellulose into glucose monomers that can be used as an energy source by the animal.Carbohydrates serve other functions in different animals. Arthropods, such as insects, spiders, and crabs, have an outer skeleton, called the exoskeleton, which protects their internal body parts. This exoskeleton is made of the biological macromolecule chitin, which is a nitrogenous carbohydrate. It is made of repeating units of a modified sugar containing nitrogen.Thus, through differences in molecular structure, carbohydrates are able to serve the very different functions of energy storage (starch and glycogen) and structural support and protection (cellulose and chitin) (Figure 16)Careers in Action: Registered DietitianObesity is a worldwide health concern, and many diseases, such as diabetes and heart disease, are becoming more prevalent because of obesity. This is one of the reasons why registered dietitians are increasingly sought after for advice. Registered dietitians help plan food and nutrition programs for individuals in various settings. They often work with patients in health-care facilities, designing nutrition plans to prevent and treat diseases. For example, dietitians may teach a patient with diabetes how to manage blood sugar levels by eating the correct types and amounts of carbohydrates. Dietitians may also work in nursing homes, schools, and private practices.To become a registered dietitian, one needs to earn at least a bachelor’s degree in dietetics, nutrition, food technology, or a related field. In addition, registered dietitians must complete a supervised internship program and pass a national exam. Those who pursue careers in dietetics take courses in nutrition, chemistry, biochemistry, biology, microbiology, and human physiology. Dietitians must become experts in the chemistry and functions of food (proteins, carbohydrates, and fats).LipidsLipids include a diverse group of compounds that are united by a common feature. Lipids are hydrophobic (“water-fearing”), or insoluble in water, because they are nonpolar molecules. This is because they are hydrocarbons that include only nonpolar carbon-carbon or carbon-hydrogen bonds. Lipids perform many different functions in a cell. Cells store energy for long-term use in the form of lipids called fats. Lipids also provide insulation from the environment for plants and animals (Figure 17). For example, they help keep aquatic birds and mammals dry because of their water-repelling nature. Lipids are also the building blocks of many hormones and are an important constituent of the plasma membrane. Lipids include fats, oils, waxes, phospholipids, and steroids.A fat molecule, such as a triglyceride, consists of two main components—glycerol and fatty acids. Glycerol is an organic compound with three carbon atoms, five hydrogen atoms, and three hydroxyl (?OH) groups. Fatty acids have a long chain of hydrocarbons to which an acidic carboxyl group is attached, hence the name “fatty acid.” The number of carbons in the fatty acid may range from 4 to 36; most common are those containing 12 to -18 carbons. In a fat molecule, a fatty acid is attached to each of the three oxygen atoms in the ?OH groups of the glycerol molecule with a covalent bond (Figure 18).During this covalent bond formation, three water molecules are released. The three fatty acids in the fat may be similar or dissimilar. These fats are also called triglycerides because they have three fatty acids. Some fatty acids have common names that specify their origin. For example, palmitic acid, a saturated fatty acid, is derived from the palm tree. Arachidic acid is derived from Arachis hypogaea, the scientific name for peanuts.Fatty acids may be saturated or unsaturated. In a fatty acid chain, if there are only single bonds between neighboring carbons in the hydrocarbon chain, the fatty acid is saturated. Saturated fatty acids are saturated with hydrogen; in other words, the number of hydrogen atoms attached to the carbon skeleton is maximized.When the hydrocarbon chain contains a double bond, the fatty acid is an unsaturated fatty acid.Most unsaturated fats are liquid at room temperature and are called oils. If there is one double bond in the molecule, then it is known as a monounsaturated fat (e.g., olive oil), and if there is more than one double bond, then it is known as a polyunsaturated fat (e.g., canola oil).Saturated fats tend to get packed tightly and are solid at room temperature. Animal fats with stearic acid and palmitic acid contained in meat, and the fat with butyric acid contained in butter, are examples of saturated fats. Mammals store fats in specialized cells called adipocytes, where globules of fat occupy most of the cell. In plants, fat or oil is stored in seeds and is used as a source of energy during embryonic development.Unsaturated fats or oils are usually of plant origin and contain unsaturated fatty acids. The double bond causes a bend or a “kink” that prevents the fatty acids from packing tightly, keeping them liquid at room temperature. Olive oil, corn oil, canola oil, and cod liver oil are examples of unsaturated fats. Unsaturated fats help to improve blood cholesterol levels, whereas saturated fats contribute to plaque formation in the arteries, which increases the risk of a heart attack.In the food industry, oils are artificially hydrogenated to make them semisolid, leading to less spoilage and increased shelf life. Simply speaking, hydrogen gas is bubbled through oils to solidify them. During this hydrogenation process, double bonds of the cis-conformation in the hydrocarbon chain may be converted to double bonds in the trans-conformation. This forms a trans-fat from a cis-fat. The orientation of the double bonds affects the chemical properties of the fat (Figure 19)..Margarine, some types of peanut butter, and shortening are examples of artificially hydrogenated trans-fats. Recent studies have shown that an increase in trans-fats in the human diet may lead to an increase in levels of low-density lipoprotein (LDL), or “bad” cholesterol, which, in turn, may lead to plaque deposition in the arteries, resulting in heart disease. Many fast food restaurants have recently eliminated the use of trans-fats, and U.S. food labels are now required to list trans-fat content.Essential fatty acids are fatty acids that are required but not synthesized by the human body. Consequently, they must be supplemented through the diet. Omega-3 fatty acids fall into this category and are one of only two known essential fatty acids for humans (the other being omega-6 fatty acids). They are a type of polyunsaturated fat and are called omega-3 fatty acids because the third carbon from the end of the fatty acid participates in a double bond.Salmon, trout, and tuna are good sources of omega-3 fatty acids. Omega-3 fatty acids are important in brain function and normal growth and development. They may also prevent heart disease and reduce the risk of cancer.Like carbohydrates, fats have received a lot of bad publicity. It is true that eating an excess of fried foods and other “fatty” foods leads to weight gain. However, fats do have important functions. Fats serve as long-term energy storage. They also provide insulation for the body. Therefore, “healthy” unsaturated fats in moderate amounts should be consumed on a regular basis.Phospholipids are the major constituent of the plasma membrane. Like fats, they are composed of fatty acid chains attached to a glycerol or similar backbone. Instead of three fatty acids attached, however, there are two fatty acids, and the third carbon of the glycerol backbone is bound to a phosphate group. The phosphate group is modified by the addition of an alcohol.A phospholipid has both hydrophobic and hydrophilic regions. The fatty acid chains are hydrophobic and exclude themselves from water, whereas the phosphate is hydrophilic and interacts with water.Cells are surrounded by a membrane, which has a bilayer of phospholipids. The fatty acids of phospholipids face inside, away from water, whereas the phosphate group can face either the outside environment or the inside of the cell, which are both aqueous.Steroids and WaxesUnlike the phospholipids and fats discussed earlier, steroids have a ring structure. Although they do not resemble other lipids, they are grouped with them because they are also hydrophobic. All steroids have four linked carbon rings and several of them, like cholesterol, have a short tail.Cholesterol is a steroid. Cholesterol is mainly synthesized in the liver and is the precursor of many steroid hormones, such as testosterone and estradiol. It is also the precursor of vitamins E andK and the precursor of bile salts, which help in the breakdown of fats and their subsequent absorption by cells. Although cholesterol is often spoken of in negative terms, it is necessary for the proper functioning of the body. It is a key component of the plasma membranes of animal cells.Waxes are made up of a hydrocarbon chain with an alcohol (?OH) group and a fatty acid. Examples of animal waxes include beeswax and lanolin. Plants also have waxes, such as the coating on their leaves, that helps prevent them from drying out.For an additional perspective on lipids, explore “Biomolecules: The Lipids” through this interactive animation:http://openstaxcollege.org/l/lipids.ProteinsProteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective; they may serve in transport, storage, or membranes; or they may be toxins or enzymes. Each cell in a living system may contain thousands of different proteins, each with a unique function. Their structures, like their functions, vary greatly. They are all, however, polymers of amino acids, arranged in a linear sequence.The functions of proteins are very diverse because there are 20 different chemically distinct amino acids that form long chains, and the amino acids can be in any order. For example, proteins can function as enzymes or hormones. Enzymes, which are produced by living cells, are catalysts in biochemical reactions (like digestion) and are usually proteins. Each enzyme is specific for the substrate (a reactant that binds to an enzyme) upon which it acts. Enzymes can function to break molecular bonds, to rearrange bonds, or to form new bonds. An example of an enzyme is salivary amylase, which breaks down amylose, a component of starch.Hormones are chemical signaling molecules, usually proteins or steroids, secreted by an endocrine gland or group of endocrine cells that act to control or regulate specific physiological processes, including growth, development, metabolism, and reproduction. For example, insulin is a protein hormone that maintains blood glucose levels.Proteins have different shapes and molecular weights; some proteins are globular in shape whereas others are fibrous in nature. For example, hemoglobin is a globular protein, but collagen, found in our skin, is a fibrous protein. Protein shape is critical to its function. Changes in temperature, pH, and exposure to chemicals may lead to permanent changes in the shape of the protein, leading to a loss of function or denaturation (to be discussed in more detail later). All proteins are made up of different arrangements of the same 20 kinds of amino acids.Amino acids are the monomers that make up proteins. Each amino acid has the same fundamental structure, which consists of a central carbon atom bonded to an amino group (?NH2), a carboxyl group (?COOH), and a hydrogen atom. Every amino acid also has another variable atom or group of atoms bonded to the central carbon atom known as the R group. The R group is the only difference in structure between the 20 amino acids; otherwise, the amino acids are identical (Figure 20).The chemical nature of the R group determines the chemical nature of the amino acid within its protein (that is, whether it is acidic, basic, polar, or nonpolar).The sequence and number of amino acids ultimately determine a protein’s shape, size, and function. Each amino acid is attached to another amino acid by a covalent bond, known as a peptide bond, which is formed by a dehydration reaction. The carboxyl group of one amino acid and the amino group of a second amino acid combine, releasing a water molecule. The resulting bond is the peptide bond.The products formed by such a linkage are called polypeptides. While the terms polypeptide and protein are sometimes used interchangeably, a polypeptide is technically a polymer of amino acids, whereas the term protein is used for a polypeptide or polypeptides that have combined, have a distinct shape, and have a unique function.Evolution in Action: The Evolutionary Significance of Cytochrome cCytochrome c is an important component of the molecular machinery that harvests energy from glucose. Because this protein’s role in producing cellular energy is crucial, it has changed very little over millions of years. Protein sequencing has shown that there is a considerable amount of sequence similarity among cytochrome c molecules of different species; evolutionary relationships can be assessed by measuring the similarities or differences among various species’ protein sequences.For example, scientists have determined that human cytochrome c contains 104 amino acids. For each cytochrome c molecule that has been sequenced to date from different organisms, 37 of these amino acids appear in the same position in each cytochrome c. This indicates that all these organisms are descended from a common ancestor. On comparing the human and chimpanzee protein sequences, no sequence difference was found. When human and rhesus monkey sequences were compared, a single difference was found in one amino acid. In contrast, human-to-yeast comparisons show a difference in 44 amino acids, suggesting that humans and chimpanzees have a more recent common ancestor than humans and the rhesus monkey, or humans and yeast.Protein StructureAs discussed earlier, the shape of a protein is critical to its function. To understand how the protein gets its final shape or conformation, we need to understand the four levels of protein structure: primary, secondary, tertiary, and quaternary (Figure 21).The unique sequence and number of amino acids in a polypeptide chain is its primary structure. The unique sequence for every protein is ultimately determined by the gene that encodes the protein. Any change in the gene sequence may lead to a different amino acid being added to the polypeptide chain, causing a change in protein structure and function. In sickle cell anemia, the hemoglobin ? chain has a single amino acid substitution, causing a change in both the structure and function of the protein. What is most remarkable to consider is that a hemoglobin molecule is made up of two alpha chains and two beta chains that each consist of about 150 amino acids. The molecule, therefore, has about 600 amino acids. The structural difference between a normal hemoglobin molecule and a sickle cell molecule—that dramatically decreases life expectancy—is a single amino acid of the 600.Because of this change of one amino acid in the chain, the normally biconcave, or disc-shaped, red blood cells assume a crescent or “sickle” shape, which clogs arteries. This can lead to a myriad of serious health problems, such as breathlessness, dizziness, headaches, and abdominal pain for those who have this disease.Folding patterns resulting from interactions between the non-R group portions of amino acids give rise to the secondary structure of the protein. The most common are the alpha (?)-helix and beta (?)- pleated sheet structures. Both structures are held in shape by hydrogen bonds. In the alpha helix, the bonds form between every fourth amino acid and cause a twist in the amino acid chain.In the ?-pleated sheet, the “pleats” are formed by hydrogen bonding between atoms on the backbone of the polypeptide chain. The R groups are attached to the carbons and extend above and below the folds of the pleat. The pleated segments align parallel to each other, and hydrogen bonds form between the same pairs of atoms on each of the aligned amino acids. The ?-helix and ?-pleated sheet structures are found in many globular and fibrous proteins.The unique three-dimensional structure of a polypeptide is known as its tertiary structure. This structure is caused by chemical interactions between various amino acids and regions of the polypeptide. Primarily, the interactions among R groups create the complex three-dimensional tertiary structure of a protein. There may be ionic bonds formed between R groups on different amino acids, or hydrogen bonding beyond that involved in the secondary structure. When protein folding takes place, the hydrophobic R groups of nonpolar amino acids lie in the interior of the protein, whereas the hydrophilic R groups lie on the outside. The former types of interactions are also known as hydrophobic interactions. In nature, some proteins are formed from several polypeptides, also known as subunits, and the interaction of these subunits forms the quaternary structure. Weak interactions between the subunits help to stabilize the overall structure. For example, hemoglobin is a combination of four polypeptide subunits.Each protein has its own unique sequence and shape held together by chemical interactions. If the protein is subject to changes in temperature, pH, or exposure to chemicals, the protein structure may change, losing its shape in what is known as denaturation, as discussed earlier. Denaturation is often reversible because the primary structure is preserved if the denaturing agent is removed, allowing the protein to resume its function. Sometimes denaturation is irreversible, leading to a loss of function. One example of protein denaturation can be seen when an egg is fried or boiled. The albumin protein in the liquid egg white is denatured when placed in a hot pan, changing from a clear substance to an opaque white substance. Not all proteins are denatured at high temperatures; for instance, bacteria that survive in hot springs have proteins that are adapted to function at those temperatures.For an additional perspective on proteins, explore “Biomolecules: The Proteins” through this interactive animation (http://openstaxcollege.org/l/proteins)Nucleic AcidsNucleic acids are key macromolecules in the continuity of life. They carry the genetic blueprint of a cell and carry instructions for the functioning of the cell.The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material found in all living organisms, ranging from single-celled bacteria to multicellular mammals.The other type of nucleic acid, RNA, is mostly involved in protein synthesis. The DNA molecules never leave the nucleus but instead use an RNA intermediary to communicate with the rest of the cell. Other types of RNA are also involved in protein synthesis and its regulation.DNA and RNA are made up of monomers known as nucleotides. The nucleotides combine with each other to form a polynucleotide, DNA or RNA. Each nucleotide is made up of three components: a nitrogenous base, a pentose (five-carbon) sugar, and a phosphate group (Figure 22). Each nitrogenous base in a nucleotide is attached to a sugar molecule, which is attached to a phosphate group.DNA Double-Helical StructureDNA has a double-helical structure (Figure 23). It is composed of two strands, or polymers, of nucleotides. The strands are formed with bonds between phosphate and sugar groups of adjacent nucleotides. The strands are bonded to each other at their bases with hydrogen bonds, and the strands coil about each other along their length, hence the “double helix” description, which means a double spiral.The alternating sugar and phosphate groups lie on the outside of each strand, forming the backbone of the DNA. The nitrogenous bases are stacked in the interior, like the steps of a staircase, and these bases pair; the pairs are bound to each other by hydrogen bonds. The bases pair in such a way that the distance between the backbones of the two strands is the same all along the molecule. Key Termsacid a substance that donates hydrogen ions and therefore lowers pHadhesion the attraction between water molecules and molecules of a different substanceamino acid a monomer of a proteinanion a negative ion formed by gaining electronsatomic number the number of protons in an atombase a substance that absorbs hydrogen ions and therefore raises pHbuffer a solution that resists a change in pH by absorbing or releasing hydrogen or hydroxide ionscarbohydrate a biological macromolecule in which the ratio of carbon to hydrogen to oxygen is 1:2:1; carbohydrates serve as energy sources and structural support in cellscation a positive ion formed by losing electronscellulose a polysaccharide that makes up the cell walls of plants and provides structural support to the cellchemical bond an interaction between two or more of the same or different elements that results in the formation of moleculeschitin a type of carbohydrate that forms the outer skeleton of arthropods, such as insects and crustaceans, and the cell walls of fungicohesion the intermolecular forces between water molecules caus

Discuss the pros and cons for each system.

For this week’s contribution to the overall Key Assignment, you will build a list of candidate information systems and the applications they support that could solve the organizational issues identified in your Unit 1 IP. The new content should go in the Suggested Information Systemsand Applications They Support section of the Key Assignment template.Assignment GuidelinesAdd the following new content to your working template:Week 2: Suggested Information Systems and Applications They SupportUsing the chart below as a guide, build a list of at least 5 candidate information systems, and describe the applications they support to solve the organizational issues identified in your Unit 1 IP.For each information system, include what it takes to operate and maintain it.Mention which potential business strategic objectives each system could support.Discuss the pros and cons for each system.Make sure the document is in APA format.Submit the document for grading.Candidate Information SystemOrganizational Issue it SolvesApplications It SupportsOperationand Maintenance ConsiderationBusiness Strategic ObjectiveProsand Cons Of ISSee Attachment Below

Share a personal connection that identifies specific knowledge and theories from this course.

Provide a 500 word (or 2 pages double spaced) minimum reflection.Use of proper APA formatting and citations. If supporting evidence from outside resources is used those must be properly cited.Share a personal connection that identifies specific knowledge and theories from this course.Demonstrate a connection to your current work environment. If you are not employed, demonstrate a connection to your desired work environment.You should not, provide an overview of the assignments assigned in the course. The assignment asks that you reflect how the knowledge and skills obtained through meeting course objectives were applied or could be applied in the workplace.Be sure to not self-plagiarize as this assignment is similar in multiple courses.Requirements: 500 wordsI have posted the question and syllabus pdf of current classplease use proper APA formatting and citations. If supporting evidence from outside resources is used it must be properly cited, and no plagiarism, please. Thank you

Choose a symbol from either “The Gift of the Magi” or     “Everyday Use” and discuss what significance this     symbol had to you as the reader

Term 6 Unit 6 DiscussionUnit 6 DB: The symbols of your life (ENG130 Literature & Composition)Initial response: Henry and Walker provide stories that include symbols that are life-changing for the protagonist(s). In two or more well-developed paragraphs, answer the following prompts:Choose a symbol from either “The Gift of the Magi” or “Everyday Use” and discuss what significance this symbol had to you as the reader (an example of this would be the combs Jim gave to Della and a discussion about a precious gift that you received or gave). Use text examples in this section.If someone were to write your life story, what symbol would be present and why? How does this symbol represent you? You can attach a picture of your symbol (an example of this might be a baby blanket from your childhood, or a baseball from your first game).Unit 6 Discussion: Implications of Cost of Capital and Capital Budgeting (FIN201 Principles of Finance)In considering what we have learned thus far regarding the importance of determining the cost of capital as well using capital budgeting tools, explain why it is important to understand that capital budgeting is subject to the validity of the forecasted data. Additionally, explain whether this reduces the reliability of these types of tools. Are there any other alternatives, or are these tools some of the most reliable that currently exist?*Unit 6 DB: The importance of DATE Functions (CIS250 Advanced Excel)Make sure to review Chapter 7. In this unit, you learned how to use a number of DATE Functions like, YEAR AND YEARFRAC.Why are these DATE Functions important in Excel?Pick one of the DATE Functions used in this unit or pick one found in Table 7.1 on Page 438. (ON PAGE 2 OF THE ATTACHED DOCUMENT)Explain how it is used and when it could be used in Excel.Table 7.1 Date Functions Function Description SyntaxDATE functionDisplays the date when provided with the numeric year, month, and date arguments; useful to display a complete date that is built from individual cells containing the year, month, and day =DATE(year,month,day)DAYS360 function Calculates the number of days between two dates based on a 360-day year using 30 days per month =DAYS360(start_date, end_date,[method])EDATE function Displays the serial number representing a date X number of months in the future or past from a given date; use a minus sign at the beginning of the months argument to calculate the serial number for a date in the past =EDATE(start_date, months)EOMONTH function Displays the serial number representing the last day of a month that is X number of months from a given date; use a minus sign at the beginning of the months argument to calculate the serial number for a date in the past =EOMONTH(start_date,months)ISOWEEKNUM function Returns the number of the week within the year for the specific date=ISOWEEKNUM(date)NETWORKDAYS function Calculates the number of work days (excluding weekends) between two dates; can optionally exclude federal and state holidays as well as other nonwork days=NETWORKDAYS(start_date,end_date,[holidays])WORKDAY function Calculates a serial number of a date, given a specified number of days before or after a date, excluding specified holidays =WORKDAY(start_day, days,[holidays])*Long-term Assets Discussion (ACCT1105 Financial Accounting)Top of Form1. What is Long Term Assets? Explain the characteristics of long term assets.2. Explain your understanding of the concept of “Lease” and state the parties to a lease contract.3. Explain your understanding of the concept of “Depreciation”4. Explain the following concepts.a. Book Valueb. Initial Costc. Expected Useful Lifed. Residual Value5. Explain your understanding of the following methods of depreciation.a. Straight-Line Methodb. Units-of- activities Methodc. Double Decline Balance Method.6. Compare and contrast Revenue Expenditure and Capital Expenditure.7. What are the characteristics of Natural Resources?8. Explain your understanding of Intangible assets and give three examples.

Based on the amendment you chose, discuss at least two challenges facing members of the law enforcement community as they endeavor to fight cyber crime and cyber criminals.

Legal Challenges and Shifting Enforcement StrategiesPrior to beginning work on this discussion, read Chapters 14 and 15 in the text and the Internet of Things: Finding a Way Out of the Security Nightmare(Links to an external site.) article (Ranger, 2016).Cyber crime brings with it many interesting and critical challenges to law enforcement. Some of the most important issues surrounding debates over how to combat cyber crime center upon the Fourth and Fifth Amendments to the Constitution.For this discussion you must select either the Fourth or Fifth Amendment for your initial post.Based on the amendment you chose, discuss at least two challenges facing members of the law enforcement community as they endeavor to fight cyber crime and cyber criminals.Evaluate legal issues, relevant to the amendment you chose, which can arise in efforts to prevent and detect crime.

Describe the effect of acupuncture on pain management

1) Minimum 9 pages (No word count per page)- Follow the 3 x 3 rule: minimum of three paragraphs per pageYou must strictly comply with the number of paragraphs requested per page.Part 1: minimum 3 pages and two paragraphs (Due 20 hours) – MLA formatPart 2: minimum 5 pages and one paragraph (Due 24 hours) – APA formatSubmit 1 document per part2)¨******APA normsAll paragraphs must be narrative and cited in the text- each paragraphBulleted responses are not acceptedDon’t write in the first personDon’t copy and paste the questions.Answer the question objectively, do not make introductions to your answers, answer it when you start the paragraphSubmit 1 document per part3)****************************** It will be verified by Turnitin (Identify the percentage of exact match of writing with any other resource on the internet and academic sources, including universities and data banks)********************************It will be verified by SafeAssign (Identify the percentage of similarity of writing with any other resource on the internet and academic sources, including universities and data banks)4) Minimum 3 references (APA format) per part not older than 5 years (Journals, books) (No websites)Part1: Minimum 7 references (APA format) per part not older than 5 years (Journals, books) (No websites) (Check file attached)All references must be consistent with the topic-purpose-focus of the parts. Different references are not allowed.5) Identify your answer with the numbers, according to the question. Start your answer on the same line, not the nextExample:Q 1. Nursing is XXXXXQ 2. Health is XXXX6) You must name the files according to the part you are answering:Example:Part 1.docPart 2.doc__________________________________________________________________________________Part 1: Acupuncture- MLA formatTopic: Health benefits of acupuncture1. Introduction (One paragraph):a. What is acupuncture (Pap3r 3)b. Explain for what acupuncture started to be used (Pap3r 2)c. When started to use acupuncture in health? (Pap3r 2)2. Pain managementa. Describe the effect of acupuncture on pain management (Pap3r 1)-(Two paragraphs)b. Describe the analgesic mechanism of acupuncture to relieve the pain (Pap3r 1)- (One paragraph)3. Reduce stress levelsa. Describe how acupuncture reduces stress levels (Pap3r 4)- (Two paragraphs)b. Describe the effect of acupuncture in NS to reduce stress levels (Pap3r 5 and 6)- (One paragraph)4. Decrease the use of addictive prescription drugsa. Describe why acupuncture decreases the use of addictive prescription drugs (Pap3r 1) (Two paragraphs)b. Describe how acupuncture decreases the opioids epidemic in the USA (Pap3r 7)- (One paragraph)5. Conclusion addressing how acupuncture helps pain management, reduces stress levels, and addictive prescription drugs (One paragraph)Part 2: Assessment, pharmacology and pathophysiology2. Describe the pharmacology treatment for Sinusitis in pediatrics (One paragraph)1. Describe the pharmacology treatment for Asthma (One paragraph)2. How to assess in consult Croup (One paragraph)3. How to assess in consult Chlamydia (One paragraph)4. Describe the pharmacology treatment for Human papillomavirus (HPV) (One paragraph)5. Describe the pharmacology treatment for Syphilis (One paragraph)7. Describe the pharmacology treatment for Renal Insufficiency in adults (One paragraph)

Over the centuries – even in the present – how have the people living in Europe developed a separate “European” identity by contrasting themselves with an external (and/or internal) “other”, defined religiously, culturally, racially, or any other way?

Over the centuries – even in the present – how have the people living in Europe developed a separate “European” identity by contrasting themselves with an external (and/or internal) “other”, defined religiously, culturally, racially, or any other way?

Explain the differences between finance, accounting, and financial reporting structures.

In about (900-1,100 words) that describe the following points:Explain the differences between finance, accounting, and financial reporting structures.Explain how they work together towards meeting the objectives of a strategic plan to meet financial viability.Explain how finance and accounting meet the auditing requirement of the Centers for Medicareand Medicaid Services (CMS), state regulatory bodies, and any other necessary accrediting bodies.Includereferences to your textbook and two additional scholarly sources.

do you think that government regulators should impose openness rules on mobile app marketplaces? Explain why or why not.

(250 words + one reputable source) For apps to be featured on the iPhone, developers must build it with Apple’s software development kit and then apply for approval. Apple rejected the Google Voice iPhone App, and further stated that it would not accept any applications that incorporated Google Voice functionality. Apple reasoned that this app duplicates the phone’s core features. It also rejected Google’s location-based app Google Latitude. However, the underlying reason was that Google’s application duplicated core services offered by Apple’s exclusive partner, AT&T. Using your knowledge from the Net Neutrality debate in Forum 1, do you think that government regulators should impose openness rules on mobile app marketplaces? Explain why or why not.

What is your strategy in collecting quality data for the model?

we completed a reflection on application of big data analytics in optimization of supply and demand chain. In this process, you are required to identify an applicable analytics method along with the required data. Justify your reasoning for the selected method in addressing your targeted problem. What is your strategy in collecting quality data for the model?Instructions:Label your Word document as follows: yourlastname.doc (ex: Johnson.docx)not bullet formatMinimum 5-10 full pages of content (does not include cover page, abstract, nor reference pages)All charts, graphs, pictures are to go in the appendix (not a substitute for content)Make sure you use credible and reliable resources – 5 minimum (2 peer-reviewed); format in APARefrain from excessive use of quotes in your response (less than 5%)Once you submit your document to the assignment folder it will automatically be loaded to TURNITIN.COM within the course. Your similarity scan score must be 20% or less (the following will be excluded: headers, bibliography, etc. prior to instructor grading paper—focus on the content of scan percentagePlagiarism will result in an automatic zero for this assignmentThere are no late assignments accepted after the last day of the course

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