BioChem C785 - WGU - Module 2 - all questions with complete solutions

BioChem C785 - WGU - Module 2 - all questions Deedra's dad has Alzheimer's Disease (AD) which is caused by a change in protein structure Correct Answer: True Alzheimer's disease is caused by aggregation of the Amyloid beta peptide and tangle formation by the tau protein. What kinds of amino acids are likely to drive the formation of these protein aggregates? Correct Answer: hydrophobic After learning about Alzheimer's disease and one of the drugs used in its treatment, what other drug design strategies could you use to offer treatment for AD? Correct Answer: 1. Drugs that break up the amyloid plaques 2. Drugs that block the production of amyloid beta peptide 3. drugs that inhibits the aggregation of protein structures A substrate binds to an enzyme at a specific site is referred to as Correct Answer: an active site You are in charge of designing a drug that inhibits the activity of a specific enzyme. An important criteria for the drug selection is to ensure that the drug is directly in competition with the original substrate when binding to the active site of the enzyme. What inhibitor would be an ideal choice? Correct Answer: A competitive inhibitor These factors can affect the protein folding and activity of an enzyme: Correct Answer: 1. pH 2. Heat 3. Reducing agents One way a cell can avoid overproduction of a molecule is by using a particular type of inhibition in which the molecule itself acts as an inhibitor for an enzyme in its production pathway. This type of regulation is known as feedback inhibition Correct Answer: True What type of enzyme adds a phosphate to another molecule? Correct Answer: Kinase What are possible effects that phosphorylation/dephosphorylation can have on the activity of an enzyme? Correct Answer: 1. turn the enzyme on 2. turn the enzyme off In the enzymatic cycle, the enzyme shape is changed when substrate binds and resumes its original shape when product is released after substrate is converted to product. Correct Answer: True An enzyme increases the rate of a chemical reaction by: Correct Answer: decreasing the activation energy Compared to a patient that is not on a statin medication, In a patient taking a statin medication the concentration of cholesterol would decrease, the concentration of HMG-CoA would increase, and the concentration of Acetoacetyle CoA would stay the same Correct Answer: True Primary structure consists of the order of amino acids in a protein. These are held together with peptide bonds that are formed by a dehydration reaction. Correct Answer: True What types of chain interaction stabilize the tertiary structure of proteins, including: Correct Answer: 1. ion pairs 2. hydrophobic interactions 3. hydrogen bonds 4. disulfide bonds Secondary structure of proteins Correct Answer: 1. It includes beta pleated sheets as a common form 2. it includes alpha helices as a common form 3. it involves hydrogen bonding between the backbone atoms In order to fulfill their function, proteins must fold in proper, 3-D conformations, which molecules, available in a cell, is likely to help a protein fold properly? Correct Answer: chaperone A misfolded protein can: Correct Answer: 1. can protein aggregation 2. lose normal function 3. can be degraded by the cell 4. can be the result of denaturation True about the different levels of protein structure: Correct Answer: 1. The interactions between the R groups of the amino acids make up the tertiary level structure of a protein 2. Peptide bonds between amino acids make up the primary structure of a protein 3. Two or more polypeptides each with their own secondary structure and tertiary structures come together to form a single larger quaternary structure of a protein The role that protein structure can play in the disease process: Correct Answer: Mutation of an active amino acid changes an enzymes ability to bind a substrate Aggregation of the proteins is the main reason behind many neurodegenerative diseases. What mutations will likely cause a neurodegenerative disease? Correct Answer: Replacing a polar amino acid with a non polar amino acid Which pair (protein and technique) will likely denature a protein? Correct Answer: Hydrogen bonds / ionic bonds: change in pH True statements about protein structure and stability: Correct Answer: 1. Denaturation is the loss of secondary, tertiary and quaternary structure 2. Ionic bonds between the side chains of the charged amino acids stabilize the protein 3. Denatured proteins retain their primary structure Alkaline phosphatase is produced by bone and liver in the human body. The amount of alkaline phosphatase in blood can help identify if a patient potentially has certain types of bone and/or liver-related disease, including Paget disease, hepatitis, and certain types of cancer. The optimal pH range for alkaline phosphatase activity is a pH of 8.0 to 10.0. What happens to the activity of the alkaline phosphatase at a pH of 2? Correct Answer: Significantly decreases Inhibitors that have a similar structure to a substrate of an enzyme are most likely to bind to the enzyme's active site, and be a competitive inhibitor Correct Answer: True When an inhibitor binds reversibly to a site of the enzyme that is not the active site, what type of inhibition results? Correct Answer: Noncompetitive inhibition Chymotrypsin is a digestive enzyme that has optimal activity at a pH of 7.8 and a temperature of 37 degrees C Correct Answer: 1. At a temperature of 20 degrees C, chymotrypsin will demonstrate increased activity compared to a reaction at 37 degrees C 2. At a pH of 9.5, chymotrypsin will have increased activity compared to a chymotrypsin at a pH of 7.2 3. At a temperature of 90 degrees C, chymotrypsin activity will decrease slightly Enzymes increase the rate of reaction by doing Correct Answer: 1. increasing the activation energy of a reaction 2. increasing the temperature of a reaction 3. stabilizing the product of the reaction The concept of the induced fit applies to which part of the enzymatic cycle? Correct Answer: enzyme-substrate cycle A dehydration reaction builds a polypeptide, where as a hydrolysis reaction breaks a polypeptide Correct Answer: True