L12: Intro to metabolism

Question 1

Define metabolism

Answer 1

“Totality of chemical reactions & physical changes that occur in living organisms, consisting of anabolism & catabolism”

Question 2

Define catabolism

Answer 2

Metabolic breakdown of complex substances into smaller products , with the release of energy

Question 3

Define anabolism

Answer 3

Energy requiring part of metabolism where simpler substances are transformed into more complex ones, with storage of energy

Question 4

Catabolism

1. Name ends in…
2. Generates…
3. Located in …

Answer 4

1. Lysis
2. ATP & NADH
3. Mitochondria

Question 5

Anabolism

1. Name ends in…
2. Uses…
3. Located in …

Answer 5

1. Genesis
2. Uses ATP, GTP & UTP
3. In cytosol

Question 6

Function of stepwise breakdown in metabolism

Answer 6

Releases energy in useable small ‘packages’

Question 7

What does different ‘forward’ & ‘reverse’ pathways allow?

Answer 7

Separate regulation

Question 8

W

Where is energy stored in each step of metabolism?

Answer 8

Activated carrier molecules

Question 9

What is the result of catabolic pathways?

Answer 9

ATP synthesis

Question 10

Why is hydrolysis of ATP energetically so favourable?

Answer 10

• Relives electrostatic repulsion between phosphate groups
• Release phosphate ion is stabilised; increase entropy
• ‘High energy bond’ is useful

Question 11

Why is hydrolysis of ATP to AMP + PPi much better than ATP to ADP?

Answer 11

Releases almost twice as much free energy

Question 12

Functions of ATP

Answer 12

• Used directly in cell motility & muscle contration (motor proteins)
• Used in active transport systems
• Used in metabolic control; regulates enzyme activity
• Used in metabolism to add Pi to metabolic intermediates

Question 13

Role of UTP

Answer 13

Drives synthesis of complex sugar

Question 14

Role of GTP

Answer 14

Synthesis of proteins

Question 15

Name 2 ‘high energy’ nucleotide carriers used to drive specific biosynthetic reactions

Answer 15

1. UTP
2. GTP

Question 16

Name group carried in high-energy linkage for these activated carriers:
1. ATP
2. NADH, NAPH,FADH2
3. Acetyl CoA
4. Uridine diphosphate glucose

Answer 16

1. Phosphate
2. Electrons & hydrogens
3. Acetyl group
4. Glucose

Question 17

Role of NAD+

Answer 17

Accepting H atom & carrying them to ETC to synthesis ATP

Question 18

What is transferred when H atom is transferred?

Answer 18

H+ & e-

Question 19

What happens to proton when 2 H atoms are transferred to NAD+ from a donor?

Answer 19

One proton (H+) is released to solution

Question 20

Define reduction & oxidation

Answer 20

Oxidation: loss electrons, gain O2, loss H+
Reduction: gain electrons, lose O2, gain H+

Question 21

What replaces NADP in anabolic reactions?

Answer 21

NAD

Question 22

What is acetyl-CoA a carrier of?

Answer 22

An acyl group (2C)

NOT ELECTRONS OR HYDROGENS

Question 23

What bond links acetyl group to CoA?

Answer 23

‘High energy’ thioester bond

Question 24

How many stages does catabolism of sugars, fats & amino acids occur in?

Answer 24

3 stages

Question 25

Name 3 stages of catabolism of sugars, fats & amino acids

Answer 25

1. Glycolysis
2. Beta-oxidation
3. Transamination