Met 2 Flashcards
xplain how enzymes act as catalysts of reactions. Draw graphs to show the effects of substrate concentration, temperature and pH on reactions catalysed by enzymes.
L2
“Define the role of the coenzyme NAD in the reaction catalysed by lactate dehydrogenase.”
Excerpt From: Imperial College London. “MBBS Year 1 MCD Autumn 17/18.” iBooks.
l2
“Explain how enzymes act as catalysts of reactions with reference to the reactions catalysed by lysozyme and glucose-6-phosphatase. ”
Excerpt From: Imperial College London. “MBBS Year 1 MCD Autumn 17/18.” iBooks.
L2
“Distinguish between lock and key and induced fit models of substrate-enzyme interactions. ”
L2
3 metbolite type and gas
“Sketch a cartoon of the three stages of cellular metabolism that convert food to waste products in higher organisms, illustrating the cellular location of each stage. ”
“Explain the metabolism of glucose by the process of glycolysis, recalling the key reactions, in particular those reactions that consume ATP and those that generate ATP. ”
Excerpt From: Imperial College London. “MBBS Year 1 MCD Autumn 17/18.” iBooks.
pg 427-429 Essential biology book
What is substrate-level phos[phorylation, and distinguish between this and oxidative phosphorylation
pg 71 ibook
“Distinguish between the aerobic and anaerobic metabolism of glucose with reference to the enzymes involved and the comparative efficiencies of each pathway with respect to ATP generation.”
Excerpt From: Imperial College London. “MBBS Year 1 MCD Autumn 17/18.” iBooks.
(met 3 slide 24)“Pyruvate generated in glycolysis has three possible fates including alcoholic fermentation (yeasts) and the generation of lactate under the control of the enzyme lactate dehydrogenase.
This process is anaerobic and is characteristic of mammalian muscle during intense activity when oxygen is a limiting factor. It allows NAD+ to be regenerated and thus glycolysis to continue, in conditions of oxygen deprivation. i.e. conditions in which the rate of NADH formation by glycolysis is greater than its rate of oxidation by the respiratory chain. NAD+, you recall, is needed for the dehydrogenation of glyceraldehyde 3-phosphate, which is the first step in generating ATP for the body (Lecture 2).
”
Excerpt From: Imperial College London. “MBBS Year 1 MCD Autumn 17/18.” iBooks.
“Summarise the reactions catalysed by lactate dehydrogenase and creatine kinase and explain the diagnostic relevance of their appearance in plasma.
”
Excerpt From: Imperial College London. “MBBS Year 1 MCD Autumn 17/18.” iBooks.
Met 3 , slide 24-30
“Explain the oxidative decarboxylation reaction catalysed by pyruvate dehydrogenase, with reference to the product and the five co-enzymes required by this enzyme complex. ”
Excerpt From: Imperial College London. “MBBS Year 1 MCD Autumn 17/18.” iBooks.
meth 3 34 -38
“The third fate of pyruvate generated from glycolysis is the generation of acetyl CoA which occurs in the mitochondria of cells.
Pyruvate + CoA + NAD+ → acetyl CoA + CO2 + NADH
The acetyl CoA thus formed is committed to entry into the citric acid cycle and can ultimately produce ATP by the process of oxidative phosphorylation (lecture 5).
The reaction is catalysed by the pyruvate dehydrogenase complex which consists of three individual enzymes and also five co-factors. Some of these co-factors are a permanent part of the enzyme complex and are known as prosthetic groups
e.g. Pyruvate Decarboxylase has the prosthetic group thiamine pyrophosphate (TPP) and Dihydrolipoyl Dehydrogenase has the prosthetic group FAD (Flavine Adenine Dinucleotide)
“Overall, the enzyme has five steps:
(i) Decarboxylation of pyruvate to give hydroxyethyl TPP
(ii) Oxidation & transfer of hydroxyethyl TPP to lipoamide to give acetylipoamide
(iii) Transfer of the acetyl group to CoA to give acetyl CoA
(iv) Regeneration of oxidised lipoamide generating FADH2
(v) Regeneration of oxidised FAD, generating NADH”
Excerpt From: Imperial College London. “MBBS Year 1 MCD Autumn 17/18.” iBooks.
