Cell Metabolism 1 original Flashcards
What is involved in an oxidation - reduction reaction?
Electron transfer
What is involved in ligation requiring ATP cleavage?
Formation of covalent bonds eg. Carbon-carbon
What is involved in isomerisation?
Rearrangement of atoms to form isomers
What is involved in group transfer?
Transfer of one functional group to another
What is involved in a hydrolytic reaction?
Cleavage of bonds by the addition of water
What is involved in a reaction where functional groups are added or removed?
Addition of functional groups to double bonds or their removal to form double bonds
Describe the enzyme required for the phosphorylation / functional group transfer from ATP to glucose and the resulting molecule.
Hexokinase and glucose 6-phosphate
Describe the enzyme and type of reaction in glycolysis involving glucose-6-phosphate
Phosphoglucose (PG) isomerase, isomerization
Name the product produced in the isomerization of glucose-6-phosphate and describe why this step is useful
Fructose 6 phosphate; it is useful because the pentose sugar can later be split into two equal parts
Name the enzyme needed to form fructose-1,6-biphosphate and any other molecules involved
phosphofructokinase (PFK) Fructose-6-phosphate, ATP
Name the enzyme used to cleave fructose-1,6-biphosphate
Aldolase
Name the two molecules produced when fructose-1,6-biphosphate is cleaved and the type of reaction
Dihydroxyacetone phosphate and glyceraldhehyde 3-phosphate, hydrolytic cleavage
What type of reaction converts dihydroxyacetone into glyceraldehyde 3-phosphate and which enzyme is used?
Isomerization and triose phosphate isomerase
Which step in hydrolysis involves the investment of 2 molecules of ATP?
Step 1
Which step of glycolysis involves the splitting of a high energy compound?
Step 2
What is the net gain of ATP in glycolysis?
2 ATP
How many ATP are formed during stage step 2 of glycolysis?
4
What type of reaction changes glyceraldehyde-3-phosphate into 1,3-biphosphoglycerate, which enzyme is used and what other molecules are involved?
Dehydrogenation and group transfer/phosphorylation, glyceraldehyde-3-phosphate dehydrogenase, NAD+ —> reduced NADH, inorganic phosphate group is added
Which enzyme and small molecule are used to transfer a group from 1,3-biphosphoglycerate and which molecules are produced?
Phosphoglycerate kinase and 2 ADP, forming 2 3-phosphoglycerate and 2 ATP
Which enzyme forms 2-phosphoglycerate, which molecule does it act on and what type of reaction is it?
Phosphoglycerate mutase, 3-phosphoglycerate and isomerization
Which enzyme is used to remove a group from 2-phosphoglycerate and which molecule is formed? Which group is removed?
Enolase, phosphoenolpyruvate, H2O
Which enzyme is used to form pyruvate and from which molecule is it formed? Which other small molecule is formed/made in the process?
Pyruvate kinase, phosphoenolpyruvate, ATP
Name the 3 fates of pyruvate
Lactate, ethanol and acetyl CoA
Name the enzyme that converts pyruvate to lactate and which other molecules are converted in the reaction.
Lactate dehydrogenase and NADH+H+ —> NAD+ (2H add onto pyruvate). This reaction is reversible (lactate can be oxidised to form pyruvate)
Which enzyme is used to convert pyruvate to acetaldehyde? Which molecule is released during this reaction?
Pyruvate decarboxylase, carbon dioxide
Which enzyme converts acetaldehyde to ethanol?
Alcohol dehydrogenase
Which molecule is oxidised when acetaldehyde is converted to ethanol?
NADH + H+ —> NAD+ (acetaldehyde is reduced)
In aerobic respiration, what is pyruvate converted into? Which enzymes are required?
Acetyl CoA, pyruvate dehydrogenase complex
When pyruvate is converted to acetyl CoA, which other molecules are involved? Describe what happens
HS-CoA transfers to pyruvate, losing a hydrogen which goes on to NAD+, forming the reduced NADH. Carbon dioxide is released as a bi-product
Which enzyme converts Creatine phosphate to Creatine and which other molecule is made in the process?
Creatine kinase and ATP
What is the function of Creatine/Creatine phosphate
Buffer needed for phosphate to form ATP during exercise
What is the name of the high energy bond in acetyl CoA? What is special about it?
Thioester - it is readily hydrolysed and therefore acetyl CoA is ready to donate acetate (2C) to other molecules
A deficiency of which vitamin causes Beri beri?
Thiamine
What are the effects of Beri Beri?
Damage to the peripheral nervous system, weakness of the musculature and decreased cardiac output
Why is thiamine important in the pyruvate dehydrogenase complex?
It acts as a cofactor, losing a proton resulting in a carbanion which readily attack’s pyruvate
