Catalytic Stategies - Enzymes

Question 1

How carbonic anhydrases facilitate their turn over

Answer 1

Acid- base
Tuns CO2 into carbonic acid

Question 2

What are restriction enzymes?

Answer 2

Hydrolyzed DNA: Cut DNA into pieces. Magnesium dependent

Question 3

Carbonic anhydrases are categorized in the same enzyme class TF

Answer 3

True

Question 4

List the enzyme intermediates of proteolysis

Answer 4

Acyl-enzyme intermediate

Question 5

What classifies an enzyme as a protease

Answer 5

Hydrolyze the peptide bond. Bind 2 amino acids together

Question 6

How can enzymes change their conformations

Answer 6

Brake and rebuild

Question 7

Carbonic anydrases use a zinc cofactor TF

Answer 7

True
Bind to water. O- from water does a nucleophilic attack on CO2

Question 8

Restriction enzymes are an example of a type of proteases TF

Answer 8

False

Question 9

How restriction enzymes specifically recognize DNA

Answer 9

When they find a specific recognition site (base sequence) they are able to bind to DNA

Question 10

What are the properties of P-loop family of enzymes?

Answer 10

Shows dramatic induced-fit
Fit lots of substrates
Bind ATP and GTP

Question 11

What cofactor is used by most phosphate related enzymes?

Answer 11

Magnesium

Question 12

If an enzyme is classified as a serine protease, what are its charactersistics

Answer 12

Uses a serine at active site
“No edge group” hydroxyl group
Inhibitor. Blocks protease.
Serine: neutral hydrophylic amino acid exposed to water

Question 13

What is the transition-state referring to?

Answer 13

The in-between state of a reaction. Stating material > transition state> product

Question 14

What is the group initially attacked by chymotrypsin?

Answer 14

C-terminus of the aromatic amino acids.

Question 15

What is conserved among all serine proteases?

Answer 15

Homologous tertiary structure.
Different substrate, same catalytic mechanism.

Question 16

Which classes of enzymes catalyzes the hydration of CO2?

Answer 16

Carbonic anhydrase with the use of zinc.

Question 17

Carbonic anhydrase are homologous. TF

Answer 17

True

Question 18

What is the product of carbonic anhydrase?

Answer 18

Carbonic acid > bicarbonate ion

Question 19

Restriction enzymes all hydrolyze peptide bonds.

Answer 19

False

Question 20

What are the main characteristics of carbonic anhydrase enzyme class?

Answer 20

Catalyzes formation of carbonic acid using zinc-dependent mechanism
Approximation catalysis and metal ion catalysis
Carbonic acid diffuses faster, then facilitates transport out of tissue
Carbon dioxide hydration and balances pH

Question 21

What do all of the enzymes that are classified together as proteases have in common?

Answer 21

Hydrolyze a peptide bond.

Question 22

Restriction enzymes employ metal ion catalysis TF

Answer 22

True

Question 23

Carbonic anhydrases are metalloenzymes.

Answer 23

True

Question 24

Members of p-loop family of enzymes can be kinases. TF

Answer 24

True

Question 25

What do all of the proteins in the serine protease family have in common (both structurally and functionally?

Answer 25

Homologous tertiary structure. Trypsin and chymotrypsin have similar substates Resolves active site of enzymes Same catalytic mechanism. Nucleophilic attack, acetylation, deacetylation. Step 1:bind substate, step 2. Nucleophilic attack, step 3. Peptide bond cleaves, step 4. Release of carboxyl terminal.

Question 26

Restriction enzymes all bind exactly the same substate. TF

Answer 26

False

Question 27

Inorganic phosphate is a substate of some members of the p loop family of enzymes and a product of others TF

Answer 27

True

Question 28

There are four protein families within the enzyme class of proteases. Which of those four families is the best example of each of the three principles of catalysis (three principles that are not common to all enzymes)?

Answer 28

Serine proteases is best example. Compared to cysteine, aspartyl, and metalloproteases.

Question 29

There are three classes of phosphate-related enzymes. Which of those three classes would you say is most like the proteases?

Answer 29

Phophatases: they remove phosphate groups from a protein or degrade ATP and proteases break down peptide bonds or proteins.

Question 30

Restriction enzymes are regulated by allosteric regulation TF

Answer 30

False

Question 31

Carbonic anhydrases involve chelation TF

Answer 31

False?

Question 32

Which of the following is true about carbonic anhydrases?

Answer 32

True carbonic anhydrases Metalloenzymes Homologous in humans They are categorized in the same enzyme class They use zinc cofactor

Question 33

Which of the following is true about members of the p loop family of enzymes

Answer 33

They can be kinases. Inorganic phosphate is a substrate some of them and a product of others They are a protein family all descended from one ancient ploop enzyme.

Question 34

Which is true about restriction enzymes

Answer 34

They employ metal ion catalysis.