Macromolecules Study Guide PDF

Study Guide for Macromolecules Bio190 1. CARBON Forms FOUR BONDS with other atoms Tetrahedral geometry Can create wide diversity of molecules due to bonding nature of carbon The four elements that make up 96% of the body are? CARBON (C), H...

Study Guide for Macromolecules Bio190 1. CARBON Forms FOUR BONDS with other atoms Tetrahedral geometry Can create wide diversity of molecules due to bonding nature of carbon The four elements that make up 96% of the body are? CARBON (C), HYDROGEN (H), NITROGEN (N) and OXYGEN (O) Most organic molecules contain carbon skeletons Give a definition of a hydrocarbon and provide examples: Hydrocarbons contain primarily carbon and hydrogen, are hydrophobic (or lipophilic), and an example would be molecules such as gasoline, fatty acids, and cholesterol. 2. MONOMERS and POLYMERS What are the definitions of a monomer and a polymer? A monomer is a small building block that is used to make larger molecules. For instance, an amino acid is the monomer of proteins. Glucose is the monomer of glycogen. What is the definition of and use for a condensation reaction? A condensation reaction permits two or more monomers to be joined together, and a molecule of water is lost at the location of the bond. What is the definition of and use for a hydrolysis reaction? A hydrolysis reaction uses a molecule of water to insert into a chemical bond within a larger molecule in order to break the bond and split the larger molecule into smaller components, or into its monomers. 3. CARBOHYDRATES Simple sugars are known as: monosaccharides Two sugars joined to one another form a: disaccharide Multiple simple sugars joined together form a: complex carbohydrate, or polysaccharide The storage form of carbohydrate in plants is a: starch The storage form of carbohydrate in animals is: glycogen The structural form of carbohydrate found in plants is: cellulose. This is also known to be: the most plentiful/common organic compound on the planet. The structural form of carbohydrate found in animals is: chitin, which forms part of the exoskeleton of insects. The main fuel used for cellular work is: glucose (a monosaccharide) 5. LIPIDS The common name for lipids is: FATS Examples of lipids in the human body include: steroid hormones are an example of a lipid; so is adipose tissue The lipid is the only macromolecule that is NOT technically a polymer The basic structure of a triglyceride (a typical lipid) is: a molecule of glycerol bonded to 3 fatty acids Highly concentrated source of energy BUT not the body’s first choice fuel Plant fats are unsaturated and liquid at room temp. Animal fats are saturated and solid at room temp. Define ‘saturated’ versus ‘unsaturated’ fat: A saturated fat has all carbon atoms ‘saturated’, or bonded to, the maximum number of hydrogens. There are no double or triple bonds in the hydrocarbon chain. An ‘unsaturated’ fat has some of the carbons double or triple-bonded to one another so that less than the maximum number of hydrogens is bonded to the hydrocarbon chain. Phospholipids; important structural component of cell membranes (lipid bilayer membrane model Steroid hormones are based on: a molecule of cholesterol Anabolic steroids promote: building of tissue mass Know why the body needs an adequate fat supply: insulation for thermoregulation; proper nervous system function; padding around delicate internal organs; reserve fuel supply. 6. PROTEINS Proteins are a type of polymer; built by linking ______________together. Amino acids There are 20 different naturally occurring amino acids Each has its own chemical nature due to differences in ‘R’, or ‘side’ groups There are four levels of protein conformation. What are they and how can you describe them? 1. Primary; linear sequence of amino acids 2. Secondary; initial folding into alpha helices or pleated sheets 3. Tertiary; additional folding based on hydrogen bonding between nearby amino acids, giving additional 3-D structure 4. Quaternary; intact protein contains more than one polypeptide chain bonded together (for example, hemoglobin, with 4 subunit proteins; 2 alpha and 2 beta chains). Know which factors can alter protein conformation and why. For example: heat, pH changes and even altered salt concentration can denature a protein by causing it to lose some of its shape, which may also cause a loss of function. Define an enzyme. An enzyme is a special type of protein (ALL enzymes are proteins) that is able to act as a biological catalyst to enable chemical reactions to occur. Remember that ALL enzymes are proteins What does an enzyme do? The enzyme lowers the amount of activation energy needed to get the reaction going. Be able to list the characteristics of enzymes For example: they are all proteins; specific to substrate; don’t participate in reaction; reuseable; can be inhibited Define active site. The active site is the specific location on the enzyme molecule to which the substrate binds. What is induced fit? Induced fit is a way to ensure that the substrate binds strongly to the enzyme; the initial binding of substrate causes a very slight shift in the enzyme’s active site shape so that the substrate is more firmly bound. What is the substrate? The substrate is the molecule that binds to the enzyme and is participating in the chemical reaction being catalyzed by the enzyme. What is the product? The product is what is produced by the reaction. Define and give the characteristics of competitive inhibition. Competitive inhibition of an enzyme happens when a molecule that chemically resembles the true substrate binds to the active site on the enzyme. This molecule does NOT participate in any reaction, nor result in the production of any end product. It acts as an ‘imposter’ for the true substrate. By binding to the enzyme, the competitive inhibitor prevents the substrate from binding and effectively stops the reaction because of this. Competitive inhibition can be reversed by flooding the system with high amounts of true substrate. Define feedback inhibition. Feedback inhibition happens when the product of a reaction ‘feeds back’ to inhibit an enzyme somewhere near the beginning of the reaction pathway. This prevents over-production of the product of the reaction. 7. NUCLEIC ACIDS What do DNA and RNA stand for? DNA = deoxyribonucleic acid RNA = ribonucleic acid What are the differences between them? DNA is double-stranded, contains thymine, uses deoxyribose RNA is usually single-stranded, contains uracil but not thymine, uses ribose What are the components of a nucleotide? sugar, phosphate + nitrogenous base Which nitrogenous bases are found in DNA versus RNA? DNA contains thymine, adenine, cytosine and guanine RNA contains uracil INSTEAD of thymine, plus adenine, cytosine and guanine What are the base-pairing rules? In DNA, A=T, and C=G In any double-stranded region of an RNA molecule (i.e. tRNA), A=U and C=G The backbone of DNA is sugar-phosphate-sugar-phosphate What is the definition of a pyrimidine versus a purine and which bases belong to each group? A pyrimidine is a category of nitrogenous base that contains one ring in its structure; thymine and cytosine and uracil are of this type A purine is a category of nitrogenous base that contains two rings in its structure; adenine and guanine are of this type Evolutionary biologists can use their of knowledge of DNA sequences and protein sequences to establish evolutionary relationships between organisms