Exam 1 ch 14

Question 1

Reduction-Oxidation reactions (Redox)

Answer 1

oxidoreductases

Question 2

Example of oxidoreductases

Answer 2

Aldehyde dehydrogenase

Question 3

Group-tranfer reactions

Answer 3

transferases and hydrolases

Question 4

Phosphotransferase

Answer 4

transferase

Question 5

Phosphatase

Answer 5

Hydrolase

Question 6

Eliminations, Isomerizations and rearrangments

Answer 6

Isomerases/mutases

Question 7

Phosphoglycerate mutase

Answer 7

Isomerase/mutases

Phosphoglycerate mutase transfers a phosphate within a molecules. Step 8

Question 8

Breaking and making bonds

Answer 8

Lyases and Ligases

Question 9

Coproheme decarboxylase

Answer 9

Lyases

coproheme decarboxylase takes off a carboxyl group

Question 10

Pyruvate carboxylase

Answer 10

Ligase

Question 11

Oxidoreductase

Answer 11

enzyme that catalyzes the transfer of electrons from one molecule to another in a reduction reactions

Question 12

What is a transferase

Answer 12

Transfers a functional group from one molecular to another

Question 13

What is a hydrolase

Answer 13

Catalyst that uses water to break chemical bonds

Question 14

WHat is a Isomerase?

Answer 14

Convert a molecule from one isomer to another. BOnd is broken and reformed

Question 15

What is a mutase

Answer 15

Movement of a functional group from one molecule within the molecule

Question 16

What is a lyase

Answer 16

An enzyme that catalyzes the breaking of various chemical bonds by means other than hydrolysis and oxidation, often forming a new double bond or a new ring structure

Question 17

A− + B → A + B−

Answer 17

Oxidoreductases

Question 18

A−X + B ⇌ B−X + A

Answer 18

Transferases

Question 19

A−B + H2O → A−OH + B−H

Answer 19

Hydrolases

Question 20

A−B → B−A

Answer 20

Isomerases / Mutases

Question 21

A−B → A + B

Answer 21

Lyases

Question 22

A + B → A−B

Answer 22

Ligases

Question 23

What is a ligase

Answer 23

In biochemistry, a ligase is an enzyme that catalyzes the joining of two molecules by forming a new chemical bond. For example, DNA ligase links two fragments of DNA by forming a phosphodiester bond.

Question 24

ΔG = ΔH − TΔS

Answer 24

ΔG = ΔH − TΔS
ΔG = change in Gibb’s free energy
ΔH = change in enthalpy (i.e. heat)
T = temperature
ΔS = change in entropy (i.e. degrees of freedom

Question 25

What are organic cofactors called

Answer 25

coenzymes

Question 26

gibbs free energy equation

Answer 26

∆𝐺 = ∆𝐺 + 𝑅Tln [C][D]/[A][B] R = Ideal Gas Constant; 8.314 J / K∙mol T = Temperature (K); 25 ⁰C = 298 K

Question 27

THe first step of a metabolic pathway is usually?

Answer 27

irreversible

Question 28

Allosteric Control

Answer 28

Binding of regulatory molecules to enzyme that activates or inhibits the enzyme

Question 29

What is negative feedback regulation an example of

Answer 29

allosteric control

Question 30

Covalent Modification

Answer 30

Addition or removal of functional groups

Question 31

WHat is phosphorylation of amino acid side chains an example of

Answer 31

covalent modification

Question 32

Substrate Cycles

Answer 32

Modulating rates of forward & reverse reactions

Question 33

Genetic Control

Answer 33

Modulating enzyme expression

Question 34

What is inhibiting DNA transcription an example of?

Answer 34

Genetic control

Question 35

What is a phosphoanhydride bond?

Answer 35

bond that links phosphate groups

Question 36

BLANK reactions drive BLANK reactions

Answer 36

exergonic, endergonic

Question 37

Gibb's free energy

Answer 37

∆Go′ = −𝑅Tln𝐾eq

Question 38

Reactions near equilibrium (ΔG ≈ 0)

Answer 38

are reversible depending on [metabolite]

Question 39

Reactions far from equilibrium (ΔG << 0)

Answer 39

set directionality of pathway

Question 40

List four high-energy compounds (ΔG < −25 kJ/mol)

Answer 40

* NTP hydrolysis (e.g. ATP) * Thioester hydrolysis (e.g. Acetyl-CoA) * NADH redox * FADH2 redox

Question 41

The Nernst Equation

Answer 41

∆E=E-acceptor - E donor. E=E -2.303RT/nF log(products/reactants)

Question 42

First four steps to balancing redox reactions

Answer 42

Step 1. Determine if the reaction involves redox (check half-reactions) Step 2. Balance elements other than Oxygen and Hydrogen Step 3. Balance Oxygen by adding water (H 2 O) Step 4. Balance Hydrogen by adding protons (H+ )

Question 45

Step 5-7 of balancing redox reactions

Answer 45

Step 5. Balance charge by adding electrons (e−) Step 6. Balance electrons stoichiometrically Step 7. Sum half-reactions and simplify

Question 46

Hydride transfer

Answer 46

transfering a hydride ion (H plus 2 electrons)