gluconeogenesis

Question 1

what is gluconeogenesis

Answer 1

making glucose/generation of new sugar

Question 2

what is pentose phosphate pathway

Answer 2

pathway leading to the generation of pentose phosphates

Question 3

describe ethanol fermentation in yeast and the enzymes and cofactors used

Answer 3

pyruvate to acetaldehyde to ethanol

enzymes- pyruvate decarboxylase and alcohol dehydrogenase (reduces aldehyde group to alcohol, NADH dependent)

starts with end product of glycolysis, occurs in absence of oxygen, yeast generates ethanol from pyruvate

cofactors- thiamine pyrophosphate and magnesium

Question 4

what is ADH and ALDH

Answer 4

ADH- alcohol dehydrogenase
ALDH- acetaldehyde dehydrogenase

Question 5

describe the breakdown of booze

Answer 5

ethanol to ethanal/acetaldehyde to ethanoic acid/acetic acid

enzymes for each step- ADH and ALDH

Question 6

what causes alcohol flush

Answer 6

different variants of alcohol and acetaldehyde dehydrogenase, ADH1B is very efficient in converting ethanol to acetaldehyde but ALD2 is defective in metabolising acetaldehyde, so build up of acetaldehyde makes you red, body cant fully metabolise acetaldehyde so capillaries in face/neck/shoulders dilate (red)

Question 7

what is the co-enzyme form of vitamin B1 and describe the structure

Answer 7

thiamine pyrophosphate (TPP), has 2 phosphate groups attached

Question 8

name 3 metabolic pathways where TPP (thiamine pyrophosphate) is involved

Answer 8

ethanol fermentation, krebs cycle, pentose phosphate pathway

Question 9

what is a vitamin B1 deficiency called and what are its risk factors/causes and symptoms

Answer 9

called beriberi

risk factors- malnutrition, alcoholism

symptoms- swelling in leg/foot/ankle, muscle wasting, numbness, neuropathy, cardiac impairment, death

Question 10

what enzyme catalyses lactic acid fermentation (pyruvate to lactate)

Answer 10

lactate dehydrogenase

Question 11

what does lactate dehydrogenase do

Answer 11

converts pyruvate to lactate, NADH dependent, reduces keto gourp into lactic acid, strongly exergonic reaction

Question 12

where is lactic acid fermentation used

Answer 12

yogurt, kimchi, sourdough

Question 13

what is the cori cycle

Answer 13

cycle of glucose and lactate from muscle and liver

muscles-ATP produced by glycolysis for rapid contractions
liver-ATP used in synthesis of glucose in gluconeogenesis during recovery