ENZYMES (quiz)

c. noncompetitive inhibition

In which type of inhibition does the inhibitor bind to the protein at a site other than the active site? a. cooperative inhibition b. competitive inhibition c. noncompetitive inhibition d. selective inhibition

c. noncompetitive inhibition

In which type of inhibition is it not possible to restore the maximum rate of enzyme activity by adding additional substrate? a. cooperative inhibition b. competitive inhibition c. noncompetitive inhibition d. selective inhibition

A. activation energy

The amount of energy needed for a specific chemical reaction to take place is known as ________. A. activation energy B. chemical energy C. free energy D. reaction energy

d. Enzymes 1 and 3 only

The diagram below shows a metabolic pathway that generate an important hormone: A metabolic poison is able to slow the production of the hormone by inhibiting one or more of the enzymes in the pathway. The effect of adding this poison is a large increase in the amount of a reactant, a decrease in the amount of intermediate X, a slight increase in amount of intermediate Y and a large decrease in the amount of the hormone Which enzyme/s is/are the metabolic poison targeting? a. Enzyme 1 b. Enzyme 1 and 2 only c. Enzyme 2 and 3 only d. Enzymes 1 and 3 only

d. Enzyme Y has a functional active site across the narrowest range of pHs

The graph shows the effect of pH on the rate on three different enzyme-controlled reactions. The enzyme concentration is constant. Which statement about the graph is correct? a. At its optimum pH, enzyme Z has the fastest rate b. There is no pH in which both X and Y have a functional active site c. Enzyme X has a functional active site across the widest range of pHs d. Enzyme Y has a functional active site across the narrowest range of pHs

d. Ensure sufficient glucose availability

The graph shows the rate of glucose production with increasing concentration of maltaseTo ensure a graph with linear correlation, which procedure would NOT be necessary? a. Ensure temperature is kept constant b. Ensure sufficient maltose availability c. Ensure pH is kept constant d. Ensure sufficient glucose availability

c. Hydrolases

Urease is an enzyme that splits urea to carbon dioxide and ammonia through the aid of water. Which of the following enzyme classification will urease fall under? a. Isomerases b. Ligases c. Hydrolases d. Lyases

c. the protein only part of an enzyme

What is an apoenzyme? a. an enzyme made entirely of protein b. the nonprotein part of an enzyme c. the protein only part of an enzyme d. the inactive form of an enzyme

c. feedback control

What is the regulatory mechanism that product accumulation inhibits an earlier step of a reaction sequence? a. cooperative inhibition b. competitive inhibition c. feedback control d. stereospecificity

b. hydrogen

When an enzyme is subjected to temperatures above the optimum, it denatures. Which of the following bonds are the first to be disrupted by high temperatures? a. disulfide b. hydrogen c. ionic d. peptide

a. isomerase

Which classification would be correct for the enzyme that catalyzes this reaction? a. isomerase b. oxidoreductase c. transferase d. ligase

b. Oxidoreductase

Which group of enzymes will initiate transfer of electrons from one molecule to another? a. Ligase b. Oxidoreductase c. Isomerase d. Transferase

b. dehydrogenase -removal of water from substrate

. In which of the following is the pairing between enzyme type and enzyme function incorrect? a. carbohydrases -hydrolysis of glycosidic bonds in carbohydrates b. dehydrogenase -removal of water from substrate c. oxidase -oxidation of a substrate d. mutase -conversion of one structural isomer into another

c. Enzymes provide activation energy for reactions.

. Which of the statements regarding enzymes is false? a. Enzymes are proteins that function as catalysts. b. Enzymes are specific. c. Enzymes provide activation energy for reactions. d. Enzyme activity can be regulated.

c. 50°C

14. Consider the following graph for the rate of an enzyme catalyzed reaction. Approximately, what would be the optimum temperature for carrying out this reaction? a. 40°C b. 60°C c. 50°C d. 10°C

c. oxidoreductases

Below is the reaction of lactate dehydrogenase enzyme. Which group of enzymes will lactate dehydrogenase fall under? a. hydrolases b. lyases c. oxidoreductases d. transferases

b. 3.0 and 9.0

Consider the following graph for the rate of an enzyme catalyzed reaction. Approximately, what would be the optimum pH of Enzyme A and C? a. 2.0 and 8.0 b. 3.0 and 9.0 c. 4.0 and 7.0 d. 3.0 and 8.0

b. A -substrate, B -active site, C -enzyme, D -E-S complex

Consider the following image depicting enzyme behavior.Which of the following correctly characterizes the components of this model? a. A -enzyme, B -substrate, C -active site, D -E-S complex b. A -substrate, B -active site, C -enzyme, D -E-S complex c. A -active site, B -substrate, C -E-S complex, D -enzyme d. A -substrate, B -enzyme, D -E-S complex, D -active site

d. An inhibitor is present.

Consider the image depicting enzyme behavior. a. All of the added substrate is bound to the enzyme. b. All of the enzyme active sites are occupied. c. The amount of enzyme present is greater than needed by the substrate. d. An inhibitor is present.

c. The surface configuration of enzymes.

Enzymes differ from inorganic catalysts in that they are highly specific. Which property of an enzyme is responsible for this specificity? a. The insoluble nature of enzymes. b. The high molecular mass of enzymes. c. The surface configuration of enzymes. d. The absence of metallic ions in an enzyme.

b. All of the enzyme active sites are occupied.

Examine the following graph. Which of the following explains why the "line" on the graph does not continue in a linear fashion? a. All of the added substrate is bound to the enzyme. b. All of the enzyme active sites are occupied. c. The amount of enzyme present is greater than needed by the substrate. d. An inhibitor is present.

c. Trypsin would attack the body's natural proteins.

Which of the following is the reason that trypsin is synthesized as trypsinogen? a. It is simpler to synthesize trypsinogen. b. Trypsinogen is a more active enzyme than trypsin. c. Trypsin would attack the body's natural proteins. d. Trypsin is a larger molecule than trypsinogen.

b. They speed up the rate of a chemical reaction.

Which of the following is true of enzymes? a. They shift the position of a chemical equilibrium. b. They speed up the rate of a chemical reaction. c. They are non-specific in catalyzing chemical reactions. d. They are fixed and not regulated by any chemical means.

c. the lock and key model

Which of the following models of enzyme action is shown below? a. the induced fit model b. both of the choices c. the lock and key model d. none of the choices

a. activator

Which of the following will have a positive regulation of enzyme activity? a. activator b. alloster c. inhibitor d. regulator

d. a low temperature

Which one of the following conditions is least likely to denature an enzyme? a. a high temperature b. an extreme pH c. heavy metal ions d. a low temperature

c. 2 and 3 only

Which statement/s would be true regarding the action of all enzyme inhibitors? Statement 1:Bind to the active site of an enzyme Statement 2:Cause a change in the tertiary structure of an enzyme Statement 3:Reduce the rate of an enzyme catalysed reaction a. 1, 2, and 3 b. 1 and 2 only c. 2 and 3 only d. 3 only

d. 2 and 4 only

Which statements are true about the optimum temperature of all enzymes? S1: It is equal to human body temperature (36.5-37.5°C) S2: Enzyme/substrate complexes are formed at the fastest rate S3:It is the maximum temperature of an enzyme will function S4:Increasing temperature past the optimum will break bonds in the tertiary structure a. 1, 2, and 3 only b. 3 and 4 only c. 2, 3, and 4 only d. 2 and 4 only

c. hydrolase

Which type of enzyme catalyses the conversion of a dipeptide into two separate amino acids? a. decarboxylase b. dehydrogenase c. hydrolase d. oxidoreductase