Biochemistry - Lecture 1

Question 1

What metabolic pathways are preserved across different kingdoms?

Answer 1

glycolysis

photosynthesis

Question 2

Describe the energy of catabolism

Answer 2

energy yielding

Question 3

describe the energy of anabolism

Answer 3

energy requiring

Question 4

What is a redox reaction?

Answer 4

a chemical reaction allowing for the transfer of energy via the movement of electrons/ hydrogen (OIL RIG)

Question 5

what does the oxygenation of a bond say about the energy in those bonds, and the number of hydrogens?

Answer 5

more oxidised = more energy in bonds, bet less hydrogens

Question 6

What is the relationship between the energy released from catabolism and the energy required for anabolism?

Answer 6

energy released is less than the energy required for anabolism

Question 7

What does anabolism provide in the body?

Answer 7

biological building blocks

Question 8

How can catabolism and anabolism be regulated?

Answer 8

• enzymes provide tight regulation

- ATP hydrolysis improves thermodynamic unfavourability of anabolism

Question 9

What are enzymes? What are their functions?

Answer 9

proteins,

• catalyse specific reactions,
• reduce the free energy of activation

Question 10

What are the 3 characteristics of enzymes?

Answer 10

1. catalytic power
2. specificity
3. regulation

Question 11

What is the function of a kinase?

Answer 11

uses ATP to phosphorylate a substrate. uses magnesium as a co-factor

Question 12

What is the function of a phosphorylase?

Answer 12

adds PO4(^3-) group using free PO4(^3-). symbol is Pi

Question 13

What is the function of a isomerase?

Answer 13

converts one isomer to another (same formula, different structure) eg. glucose to fructose

Question 14

What is the function of epimerase?

Answer 14

creates an epimer (same formula and function, but vary around one carbon molecule)

Question 15

What is the function of a mutase?

Answer 15

moves groups of atoms within the substrate

Question 16

What is the function of a transferase?

Answer 16

moves a side chain from one substrate to another

Question 17

What is the function of a lyase?

Answer 17

breaks a carbon-carbon bond

Question 18

What is the function of a carboxylase?

Answer 18

makes a carbon-carbon bond (uses CO2 for this). uses biotin as a co-factor

Question 19

What is the function of a synthase?

Answer 19

no bonds broken, substrates converted to products without the input of energy (no ATP).

Question 20

What is the function of a synthetase?

Answer 20

same as synthase, but requires ATP

Question 21

What is the function of a dehydrogenase?

Answer 21

involves a co-factor in the reaction (NAD, NADH, etc.) 2 H atoms are removed from the substrate

Question 22

What is the function of a hydrolase?

Answer 22

uses water to break the bond

Question 23

What does an enzyme do if ‘thio’ is in the name?

Answer 23

a sulfur bond is broken

Question 24

The enzymes within a pathway are associated together, and can be…?

Answer 24

1. separate (diffuse substrates)
2. multi-enzyme complexes
3. membrane bound

Question 25

What is an amphibolic intermediate?

Answer 25

intermediates that are in both anabolic and catabolic metabolism pathways

Question 26

What are 3 key molecules for linking reactions?

Answer 26

1. glucose-6-phosphate (G6P) 2. pyruvate 3. Acetyl-CoA

Question 27

What are some key metabolites formed from G6P?

Answer 27

1. glycogen 2. pyruvate 3. ribulose-5-phosphate