2.5: Additional Enzymatic Reactions

Question 1

The ability of a microorganism to generate energy, while essential, is only part of the requirement to sustain life. Cells must also be able to maintain a functional……..

Answer 1

equilibrium—that is, they must operate within the bounds of their limitations.

Question 2

Cells maintain equilibrium (balance) by producing……..

Answer 2

….proteins known as enzymes.

Question 3

Enzymes ______ biochemical reactions.

Answer 3

accelerate or catalyze

Question 4

True or False: Since enzymes, like all catalysts, are not consumed or destroyed during the chemical reaction, they can be readily detected in the laboratory and are useful in various diagnostic tests.

Answer 4

True

Question 5

In order to maintain homeostasis, the optimal level of activity for a stable environment, enzymes are…….

Answer 5

…… very specific and will only effectively catalyze a specific chemical reaction.

Question 6

______ is an enzyme that catalyzes the breakdown of proteins. This enzyme is essential anytime we eat. If we can’t break down the steak (protein) we just consumed into smaller subunits, its nutritional and energetic potential cannot be used.

Answer 6

Protease (proteinase)

Question 7

______ is an enzyme that accelerates the decomposition of hydrogen peroxide (H2O2) into water and oxygen. Without it, a cell would be unprotected from oxidative damage by reactive oxygen species (ROS) and could not survive.

Answer 7

Catalase

Question 8

______is an enzyme that catalyzes the breakdown of lipids (fats). They provide an essential role in the metabolism of fats especially when glucose is not available.

Answer 8

Lipase

Question 9

Protease (proteinase) is an enzyme that

Answer 9

catalyzes the breakdown of proteins. This enzyme is essential anytime we eat. If we can’t break down the steak (protein) we just consumed into smaller subunits, its nutritional and energetic potential cannot be used.

Question 10

Catalase is an enzyme that

Answer 10

accelerates the decomposition of hydrogen peroxide (H2O2) into water and oxygen. Without catalase, a cell would be unprotected from oxidative damage by reactive oxygen species (ROS) and could not survive.

Question 11

Lipase is an enzyme that

Answer 11

catalyzes the breakdown of lipids (fats). Lipases provide an essential role in the metabolism of fats especially when glucose is not available.

Question 12

True or False: As enzymes serve to maintain equilibrium, inhibiting a single enzyme will not drastically alter the outcome of microbial survival.

Answer 12

False. Inhibiting even a single enzyme can drastically alter the outcome of microbial survival.

Question 13

What are the Six Major Categories of Enzymes?

Answer 13

Hydrolases: catalyze hydrolysis—the cleavage or breaking apart of chemical bonds by the addition of water. (i.e. A-B + H2O → A-OH + B-H)

Isomerases: promote intramolecular rearrangements by altering bonds and/or confirmations within the same molecule producing a different molecule having the same molecular formula, also known as an isomer. (i.e. A-B→ B-A)

Ligases: cause covalent bonds to be formed between molecules. (i.e. A + B → A-B)

Lyases: cause the cleavage (break) of bonds by means other than hydrolysis or oxidation. (i.e. A-B → A + B)

Oxidoreductases: catalyze the transfer of electrons from the reductant (electron donor) to the oxidant (electron acceptor). (i.e. A— + B →A + B—)

Transferases: act to transfer a specific functional group from one molecule to another. (i.e. Ab + C → A + Cb)

Question 14

Hydrolases

Answer 14

catalyze hydrolysis—the cleavage or breaking apart of chemical bonds by the addition of water. (i.e. A-B + H2O → A-OH + B-H)

Question 15

______ catalyze hydrolysis—the cleavage or breaking apart of chemical bonds by the addition of water. (i.e. A-B + H2O → A-OH + B-H)

Answer 15

Hydrolases

Question 16

A-B + H2O → A-OH + B-H is an example of what major enzyme?

Answer 16

Hydrolases

Question 17

Isomerases

Answer 17

promote intramolecular rearrangements by altering bonds and/or confirmations within the same molecule producing a different molecule having the same molecular formula, also known as an isomer. (i.e. A-B→ B-A)

Question 18

______ promote intramolecular rearrangements by altering bonds and/or confirmations within the same molecule producing a different molecule having the same molecular formula, also known as an isomer. (i.e. A-B→ B-A)

Answer 18

Isomerases

Question 19

A-B→ B-A is an example of what major enzyme?

Answer 19

Isomerases

Question 20

Ligases

Answer 20

cause covalent bonds to be formed between molecules. (i.e. A + B → A-B)

Question 21

______ cause covalent bonds to be formed between molecules. (i.e. A + B → A-B)

Answer 21

Ligases

Question 22

A + B → A-B is an example of what major enzyme?

Answer 22

Ligases

Question 23

Lyases

Answer 23

cause the cleavage (break) of bonds by means other than hydrolysis or oxidation. (i.e. A-B → A + B)

Question 24

______cause the cleavage (break) of bonds by means other than hydrolysis or oxidation. (i.e. A-B → A + B)

Answer 24

Lyases

Question 25

A-B → A + B is an example of what major enzyme?

Answer 25

Lyases

Question 26

Oxidoreductases

Answer 26

catalyze the transfer of electrons from the reductant (electron donor) to the oxidant (electron acceptor). (i.e. A— + B →A + B—)

Question 27

______ catalyze the transfer of electrons from the reductant (electron donor) to the oxidant (electron acceptor). (i.e. A— + B →A + B—)

Answer 27

Oxidoreductases

Question 28

A— + B →A + B— is an example of what major enzyme?

Answer 28

Oxidoreductases

Question 29

Transferases

Answer 29

act to transfer a specific functional group from one molecule to another. (i.e. Ab + C → A + Cb)

Question 30

______act to transfer a specific functional group from one molecule to another. (i.e. Ab + C → A + Cb)

Answer 30

Transferases

Question 31

Ab + C → A + Cb is an example of what major enzyme?

Answer 31

Transferases

Question 32

The specificity of an enzyme is heavily influenced by its______.

Answer 32

Active Site

Question 33

True or False: The specificity of an enzyme is heavily influenced by its active site.

Answer 33

True

Question 34

Active Site is a…….

Answer 34

………unique chemical structure bound only by select target molecules.

Question 35

The molecule undergoing the reaction, known as a _____, will bind to the active site found within the enzyme molecule.

Answer 35

Substrate

Question 36

True or False: The enzyme protein will only ever have one active site to bring in a single substrate.

Answer 36

False. The enzyme protein may also have two active sites to bring two different substrates within close proximity to one another.