Cells - Metabolism

Question 1

Glycolysis

Answer 1

See image

Question 2

Fates of Pyruvate

Answer 2

Alcohol fermentation
Pyruvate=>acetaldehyde=>ethanol
P decarboxylase Alcohol dehydrogenase

Lactate production
red NAD Pyruvate=> lactate NAD+
LDH

Acetyl CoA production
NAD+ Pyruvate=>acetyl CoA+CO2+red NAD
PDH complex

Question 3

Beri beri

Answer 3

Thiamine deficiency → thiamine is cofactor of pyruvate dehydrogenase complex
o So, deficiency of thiamine leads to Beri Beri → difficult to make acetyl CoA from pyruvate – effects on
metabolism + respiration
o SYMPTOMS: Damage to peripheral nervous system, Weakness of musculature, Decreased cardiac
output
o Brain particularly vulnerable as it relies heavily on glucose metabolism

Question 4

TCA cycle

Answer 4

Each TCA cycle produces → 2 x CO2, 3 x NADH, 1 x GTP, 1 x FADH2
o Cycle occurs once for each pyruvate molecule converted into acetyl CoA
o Reactions catalysed by mitochondrial enzymes in mitochondrial matrix space

Question 5

What molecules do all 20 amino acids degrade to?

Answer 5

Pyruvate
o Acetyl CoA
o Acetoacetyl CoA
o Alpha-ketoglutarate
o Succinyl CoA
o Fumarate
o Oxaloacetate

Question 6

What does fatty acid metabolism produce?

Answer 6

Acetyl CoA