18.2 Linking glycolysis and the Krebs cycle Flashcards
What’s the role of the link reaction/ oxidative phosphorylation
links glycolysis, which occurs in the cytoplasm
to Kreb’s cycle, which occurs in the mitochondrial matrix
Where does the link reaction take place
mitochondrial matrix
(pyruvate from glycolysis acts as reactant in link reaction, so must be actively transported into mitochondria)
Outline the process of the link reaction
Pyruvate from glycolysis actively transported into mitochondrial matrix using carrier proteins
pyruvate undergoes decarboxylation (removal of CO2)
NAD oxidises by removing hydrogen, NAD + pyruvate ⟶ NADH + Acetyl group
Acetyl group + Coenzyme A ⟶ Acetyl coenzyme A,
Acetyl coenzyme A delivers acetyl group to Kreb’s cycle
How does actyl coenzyme A act ad a coenzyme during the link reaction
transfers group of atoms from 1 reaction to another in a multi-step pathway:
coenzyme A accepts acetyl group during oxidative decarboxylation
supplies it to a later stage during Kreb’s cycle
What’s the function of the outer mitochondrial membrane
allows for compartmentalisation
by separating mitochondrion from rest of cell
What’s the function of the inner mitochondrial membrane
contains electron transport chains & ATP synthase membrane proteins
for chemiosmosis
Where are cristae found and what’s their function
projections of inner membrane
increases surface area over which oxidative phosphorylation can occur
What’s the function of the inner membrane space in the mitochondria
gap where protons are pumped into by electron transport chain
small, so used to create high concentrations of molecules
What’s the function of the mitochondrial matrix
contains mitochondrial DNA, & enzymes
for Kreb’s cycle & link reaction
____ + Coenzyme A + NAD ⟶ ____ + CO2 + ____
pyruvate, acetyl coenzyme A, NADH
What can occur to the CO2 removed during oxidative decarboxylation?
diffuse into bloodstream & removed as waste
used for photosynthesis in autotrophs
What occurs to oxidise the pyruvate molecule
removal of hydrogen atom
(hydrogen removed by NAD, forming NADH)
Pyruvate is a product of glycolysis, which occurs in the cytoplasm.
How does it enter the mitochondrial matrix to be processed in the link reaction?
Via active transport using specific carrier proteins
What are the products of the link reaction
Acetyl coenzyme A, NADH, CO2
How many times does the link reaction happen for each molecule of glucose
Twice
