Question 1

When a cofactor is a small organic molecule, it is known as a(n)

Accepted Answer

A)  isoenzyme. 
B)  vitamin. 
C)  zymogen. 
D)  coenzyme. 
E)  regulator. 
A)  isoenzyme. 
B)  vitamin. 
C)  zymogen. 
D)  coenzyme. 
E)  regulator.

Question 2

Iron(II) and iron(III) ions are used in the functioning of

Accepted Answer

A)  urease. 
B)  alcohol dehydrogenase. 
C)  creatine kinase. 
D)  the cytochrome oxidase system. 
E)  pepsin. 
A)  urease. 
B)  alcohol dehydrogenase. 
C)  creatine kinase. 
D)  the cytochrome oxidase system. 
E)  pepsin.

Question 3

Alanine transaminase is an example of a transferase enzyme.

Accepted Answer

A) True 
 B)False

Question 4

Most enzymes are

Accepted Answer

A)  fluid-mosaic proteins. 
B)  induced proteins. 
C)  substrate proteins. 
D)  fibrous proteins. 
E)  globular proteins. 
A)  fluid-mosaic proteins. 
B)  induced proteins. 
C)  substrate proteins. 
D)  fibrous proteins. 
E)  globular proteins.

Question 5

In the lock-and-key model of enzyme action, the enzyme active site is thought of as

Accepted Answer

A)  a rigid, nonflexible shape that fits the substrate exactly. 
B)  an area of the enzyme that can adjust to fit the substrate shape. 
C)  a key-like shape that fits into a pocket of the substrate surface. 
D)  a hydrophilic area on the enzyme surface. 
E)  a lock that bars a noncompetitive inhibitor from reacting. 
A)  a rigid, nonflexible shape that fits the substrate exactly. 
B)  an area of the enzyme that can adjust to fit the substrate shape. 
C)  a key-like shape that fits into a pocket of the substrate surface. 
D)  a hydrophilic area on the enzyme surface. 
E)  a lock that bars a noncompetitive inhibitor from reacting.

Question 6

Match the correct term in enzyme action with each description.
-an inorganic substance such as Mg2+ required by some enzymes for activity

Accepted Answer

A) cofactor 
B) lock-and-key theory 
C) enzyme-substrate complex 
D) active site 
E) coenzyme 
A) cofactor 
B) lock-and-key theory 
C) enzyme-substrate complex 
D) active site 
E) coenzyme

Question 7

Indicate whether each of the following is fat soluble or water soluble.
-vitamin E

Accepted Answer

The answer of Indicate whether each of the following is...

Question 8

Coenzymes such as water-soluble vitamins are needed in only small amounts because

Accepted Answer

A)  only small amounts of enzymes are present in each cell. 
B)  only small amounts of substrates are available at any one time. 
C)  they can be eliminated in the urine. 
D)  each vitamin molecule can be reused many times as a cofactor. 
E)  they can be stored in the liver for future use. 
A)  only small amounts of enzymes are present in each cell. 
B)  only small amounts of substrates are available at any one time. 
C)  they can be eliminated in the urine. 
D)  each vitamin molecule can be reused many times as a cofactor. 
E)  they can be stored in the liver for future use.

Question 9

Substances that react under the influence of an enzyme are usually held to the enzyme by

Accepted Answer

A)  peptide bonds. 
B)  side chains of amino acids in the enzyme protein. 
C)  ester bonds. 
D)  pH changes. 
E)  competitive inhibition. 
A)  peptide bonds. 
B)  side chains of amino acids in the enzyme protein. 
C)  ester bonds. 
D)  pH changes. 
E)  competitive inhibition.

Question 10

The optimum temperature for sucrase activity is 37 °C. The hydrolysis of sucrose is slowest at which temperature in the choices below?

Accepted Answer

A)  0 °C 
B)  10 °C 
C)  20 °C 
D)  25 °C 
E)  45 °C 
A)  0 °C 
B)  10 °C 
C)  20 °C 
D)  25 °C 
E)  45 °C

Question 11

Hexokinase catalyzes only the addition of phosphate to any hexose sugar. This type of activity is called

Accepted Answer

A)  regional specificity. 
B)  collateral specificity. 
C)  group specificity. 
D)  noncompetitive specificity. 
E)  general specificity. 
A)  regional specificity. 
B)  collateral specificity. 
C)  group specificity. 
D)  noncompetitive specificity. 
E)  general specificity.

Question 12

Indicate whether each of the following is fat soluble or water soluble.
-vitamin K

Accepted Answer

The answer of Indicate whether each of the following is...

Question 13

Identify each of the designated regions on the energy diagram for the conversion of a substrate to product with and without an enzyme.  
-energy of the substrate

Accepted Answer

The answer of Identify each of the designated regions on...

Question 14

Enzymes always require a cofactor.

Accepted Answer

A) True 
 B)False

Question 15

Indicate whether each of the following is fat soluble or water soluble.
-vitamin D

Accepted Answer

The answer of Indicate whether each of the following is...

Question 16

Identify the type of inhibition in each description.
-an inhibitor that forms a covalent bond with a side chain in the active site

Accepted Answer

A) noncompetitive 
B) competitive 
A) noncompetitive 
B) competitive

Question 17

To what main class of enzymes does the enzyme that catalyzes the following reaction belong? Ser-Ala → Ser + Ala

Accepted Answer

A)  oxidoreductase 
B)  transferase 
C)  hydrolase 
D)  lyase 
E)  isomerase 
A)  oxidoreductase 
B)  transferase 
C)  hydrolase 
D)  lyase 
E)  isomerase

Question 18

Consider an enzymatic reaction in which the initial concentration of substrate is low. If the amount of enzyme is held constant, but the amount of substrate is increased, the rate of an enzyme catalyzed reaction will

Accepted Answer

A)  increase in an exponential fashion. 
B)  decrease at first, then increase in a linear fashion. 
C)  increase at first in a linear fashion, then remain at a constant high rate. 
D)  stay the same. 
E)  be inhibited by the higher concentrations of substrate. 
A)  increase in an exponential fashion. 
B)  decrease at first, then increase in a linear fashion. 
C)  increase at first in a linear fashion, then remain at a constant high rate. 
D)  stay the same. 
E)  be inhibited by the higher concentrations of substrate.

Question 19

The enzymes that extract energy from biomolecules for our use are located in the

Accepted Answer

A)  plasma. 
B)  cell mitochondria. 
C)  lymph. 
D)  urine. 
E)  lipoproteins. 
A)  plasma. 
B)  cell mitochondria. 
C)  lymph. 
D)  urine. 
E)  lipoproteins.

Question 20

A diet very low in vitamin C can lead over time to the condition __________.

Accepted Answer

A)  rickets 
B)  scurvy 
C)  cancer 
D)  carpal tunnel syndrome 
E)  anorexia nervosa 
A)  rickets 
B)  scurvy 
C)  cancer 
D)  carpal tunnel syndrome 
E)  anorexia nervosa

Exam 20: Enzymes and Vitamins

When a cofactor is a small organic molecule, it is known as a(n)

Iron(II) and iron(III) ions are used in the functioning of

Alanine transaminase is an example of a transferase enzyme.

Most enzymes are

In the lock-and-key model of enzyme action, the enzyme active site is thought of as

Match the correct term in enzyme action with each description. -an inorganic substance such as Mg2+ required by some enzymes for activity

Indicate whether each of the following is fat soluble or water soluble. -vitamin E

Coenzymes such as water-soluble vitamins are needed in only small amounts because

Substances that react under the influence of an enzyme are usually held to the enzyme by

The optimum temperature for sucrase activity is 37 °C. The hydrolysis of sucrose is slowest at which temperature in the choices below?

Hexokinase catalyzes only the addition of phosphate to any hexose sugar. This type of activity is called

Indicate whether each of the following is fat soluble or water soluble. -vitamin K

Identify each of the designated regions on the energy diagram for the conversion of a substrate to product with and without an enzyme. -energy of the substrate

Enzymes always require a cofactor.

Indicate whether each of the following is fat soluble or water soluble. -vitamin D

Identify the type of inhibition in each description. -an inhibitor that forms a covalent bond with a side chain in the active site

To what main class of enzymes does the enzyme that catalyzes the following reaction belong? Ser-Ala → Ser + Ala

Consider an enzymatic reaction in which the initial concentration of substrate is low. If the amount of enzyme is held constant, but the amount of substrate is increased, the rate of an enzyme catalyzed reaction will

The enzymes that extract energy from biomolecules for our use are located in the

A diet very low in vitamin C can lead over time to the condition __________.

Chemistry and Measurements

Energy and Matter

Atoms and Elements

Nuclear Chemistry

Compounds and Their Bonds

Chemical Reactions and Quantities

Gases

Solutions

Reaction Rates and Chemical Equilibrium

Acids and Bases

Introduction to Organic Chemistry: Alkanes

Alkenes, Alkynes, and Aromatic Compounds

Alcohols, Phenols, Thiols, and Ethers

Aldehydes, Ketones, and Chiral Molecules

Carbohydrates

Carboxylic Acids and Esters

Lipids

Amines and Amides

Amino Acids and Proteins

Nucleic Acids and Protein Synthesis

Metabolic Pathways for Carbohydrates

Metabolism and Energy Production

Metabolic Pathways for Lipids and Amino Acids

Filters

Match the correct term in enzyme action with each description. -an inorganic substance such as Mg²⁺ required by some enzymes for activity