the link reaction + krebs cycle Flashcards
where does the link reaction occur
mitochondrial matrix
what is the first stage of the link reaction
pyruvate is decarboxylated, where one carbon atom is removed in the form of CO2
what happens when CO2 is removed in the link reaction
NAD is reduced to NADH by collecting a hydrogen from pyruvate to turn it into acetate
what is acetate combined with and what does it form
coenzyme A and forms acetyl CoA
is any ATP produced in the link reaction
no
how many times does the link reaction occur for every glucose molecule and why
two pyruvate molecules are made from glycolysis and only one enter the link reaction, therefore happens twice for every glucose molecule
what are the products of the link reaction for each glucose molecule (2x link reaction)
2 x acetyl CoA
2x CO2 as a waste product
2x NADH
what happens to acetyl CoA and the NADH produced in the link reaction
acetyl CoA - krebs cycle
NADH - oxidative phosphorylation
where does the krebs cycle occur
mitochondrial matrix
what is the first stage of the krebs cycle
acetyl group from acetyl CoA produced in the link reaction combines with oxaloacetate to form citric acid
which enzymes catalyses the reaction between acetyl and oxaloacetate
citrate synthase
how many carbons is acteyl CoA
2 carbon molecule
how many carbons is oxaloacetate
4 carbon compound
how many carbons is citrate
6 carbon compound
what happens to coenzyme A, when the acetyl group is used in the krebs cycle
goes back to the link reaction
what is citrate converted to
an intermediate 5 carbon compound
what happens when citrate is converted to a 5C compound
decarboxylation in the form of CO2, dehydrogenation where a hydrogen is removed which is used to produce NADH from NAD
what happens to the 5C intermediate
4C molecule is produced (oxaloacetate)
what is involved in turning the 5C intermediate into oxaloacetate
decarboxylation and dehydrogenation occur producing one molecule of FADH and two molecules of NADH
what is substrate level phosphorylation
when a phosphate group is directly transferred from one molecule to another
how does substrate level phosphorylation occur in the krebs cycle
ATP is produced from the direct transfer of a phosphate group from an intermediate compound with ADP to form oxaloacetate
what is oxaloacetate used for when produced
regenerated for use in the next krebs cycle
how many CO2 is produced from the krebs cycle
2
what is the CO2 used for
released as a waste product
how many ATP does the krebs cycle produce
1
what is the ATP used for
energy
how many NADH are produced
3
what is the NADH produced from the krebs cycle used for
oxidative phosphorylation
how many FADH are produced
1
what is the FADH produced from the krebs cycle used for
oxidative phosphorylation
