Inhibition Nucleic Acids Enzyme Structure Temp/ pH Enzymes Enzyme/Sub strate conc

Topic 1 – 10 Points QUESTION: What is the monomer of a nucleic acid? Identify all three parts ANSWER: phosphate sugar base

Topic 1 – 20 Points QUESTION: What two parts of the monomer make up the “backbone” of the nucleotide? ANSWER: phosphate and sugar

Topic 1 – 30 Points QUESTION: How do nucleotides bond? ANSWER: Phosphate joins to sugar

Topic 1 – 40 Points QUESTION: What is the job of nucleic acids? Where are each of the nucleic acids located ANSWER: Store information (RNA copies stored info and transports to the cytoplasm). DNA is only in the nucleus, RNA can be in the nucleus or the cytoplasm.

Topic 1 – 50 Points QUESTION: What are the structural differences between DNA and RNA? ANSWER: DNA 1 strand, deoxyribose sugar, ATCG RNA 2 strands ribose sugar, AUCG

Enzymes– 10 Points QUESTION: To what class of macromolecules do enzymes belong? ANSWER: Proteins

Topic 2 – 20 Points QUESTION: How does an enzyme lower activation energy? ANSWER: It positions the molecules so that they can bond using less energy

Topic 2 – 30 Points QUESTION: Identify key structures on this diagram ANSWER: Triglyceride; glycerol and 3 fatty acids, hydrolysis 3 waters (and an enzyme) required.

Topic 2 – 40 Points QUESTION: What can alter the structure of an enzyme? ANSWER: Temperature, pH, inhibitor (feedback, competitive, non-competitive

Topic 2 – 50 Points QUESTION: Differentiate between competitive and non- competitive inhibitors? ANSWER: Competitive bind to the active site, while non- competitive bind to an allosteric site.

Topic 3 – 10 Points QUESTION: What do the phrases optimal temperature and optimal pH mean? ANSWER: these are the best temperature and pH for any given enzyme they can vary depending on the enzyme

Topic 3 – 20 Points QUESTION: What is the definition of an enzyme? Are all enzymes catalysts? Are all catalysts enzymes? ANSWER: Usually a protein that speeds up a reaction. All enzymes are biological catalysts, but not all catalysts are enzymes

Topic 3 – 30 Points QUESTION: Do enzymes break down substrates or build up (synthesize) substrates ANSWER: They can do either, but an enzyme is very specific. One enzyme can break down OR synthesize one compound, (but only one type). It can repeat this reaction over and over again.

Topic 3 – 40 Points QUESTION: Are enzymes reactants or substrates, or neither? Explain ANSWER: Enzymes are neither reactants nor substrates. When writing an equation that uses an enzyme, the enzyme is always placed “over” the reaction arrow enzyme Reactants ---  Products

Topic 3 – 50 Points QUESTION: Explain Activation energy. How is it different from energy released or retained during the reaction? ANSWER: Activation energy is energy that must be put into the reaction in order for it to begin, whether or not the reaction is endothermic or exothermic

Topic 4 – 10 Points QUESTION: How is a lock and key model different from an induced fit model? ANSWER: Lock and key are enzymes with a “fixed” active site. The substrate fits “like a key”. Induced fit enzymes wrap around the ‘correct substrate”, (so movement of the active site is involved.

Topic 4 – 20 Points QUESTION: What is the effect of temperature on enzyme activity ANSWER: 1. As temp decreases from optimal, the reaction rate will slow. Cold temperatures may eventually stop enzyme reactions, but it will take a very long time, compared to those that are heated. Enzymes heated beyond their optimal will denature quickly. Depending on the damage, they may or may not be able to renature.

Topic 4 – 30 Points QUESTION: Ho w does pH affect enzyme activity ANSWER: Most enzymes have a fairly narrow pH range. Going above or below the optimal pH will cause denaturation.

Topic 4 – 40 Points QUESTION: Where are pHs unique in the human body? ANSWER: Stomach – low pH (2-4) Small intestines – higher pH Most of body is between 7 and 7.5

Topic 4 – 50 Points QUESTION: How does concentration of substrate affect enzyme activity ANSWER: If you keep the enzyme concentration constant, and prepare several different concentrations of substrate, you will see a rapid rise in enzyme activity at low concentrations of substrate ( some enzyme molecules are still empty at times. When the curve levels off, it means that the enzyme molecules are now “saturated”

Topic 5 – 10 Points QUESTION: Differentiate between coenzymes and cofactors ANSWER: Coenzymes are vitamins and cofactors are minerals

Topic 5 – 20 Points QUESTION: List three types of inhibitors ANSWER: poisons, internal (biofeedback), drugs

Topic 5 – 30 Points QUESTION: What are some examples of inhibitors ANSWER: Cyanide – oxidase Penicillan – interferes with the manufacture of the cell wall Nerve gas - acetylcholinesterase

Topic 5 – 40 Points QUESTION: What is feedback inhibition and where does it occur ANSWER: in biochemical pathways. The endproduct inhibits the first enzyme in the cycle. If there is an enzyme within the cycle that prevents the formation of the final product, the “intermediate product” can continue to accumulate, and cause problems (toxicity)

Topic 5 – 50 Points QUESTION: Differentiate between competitive and non- competitive inhibition. Draw an example of each ANSWER: (