Metabolic pathways (M12,13)

Question 1

What is primary metabolism?

Answer 1

Basic housekeeping functions
All cells need and do it- almost always constitutively
Primary metabolites produced eg sugars, amino acids, nucleotides, fats

Question 2

What is secondary metabolism?

Answer 2

Specialised functions, present in differentiated cells, inducible
Secondary metabolites produced eg antibiotics, plants produce oils, fragrances, terpenes

Question 3

Draw glycolysis

Question 4

Draw kreb cycle

Question 5

What happens in anaerobic organisms with krebs?

Answer 5

Don’t get energy from oxidative cycles or kreb cycle
Get it from other means- they are photosynthetic
However they do need parts of krebs for biosythesis so they run the cycle backwards to get synthetic precursers

Question 6

Explain pentose pyruvate pathway

Question 7

Explain link reaction

Question 8

Explain why we do beta oxidation of fatty acids

Answer 8

Generates acetyl CoA
Break down of fats mainly for energy when sugar runs out
Feeds acetyl CoA into krebs for energy
Can also use the acetyl CoA for making synthetic precursor by feeding into krebs

Question 9

Explain how beta oxidation of fatty acids occurs

Answer 9

2 oxidation reactions and 1 hydration reaction
Degraded two carbons at a time starting at beta carbon
End result is acetyl CoA

Question 10

Explain fatty acid biosynthesis
(Fatty acid synthase)

Question 11

Explain amino acid biosynthesis

Question 12

What is a transamination reaction in amino acid biosynthesis? Draw it

Question 13

Name some essential amino acids and why they are difficult to make

Question 14

Describe ribose synthesis draw it

Question 15

Describe pyrimidine base synthesis

Answer 15

Base first then attach ribose
Base atoms come from aspartate and carbamoyl phosphate (bicarb + NH3 from glutamine + 2ATP to activate)
Single ring

Question 16

Describe purine base synthesis

Answer 16

Ribose first then attach base later