Aerobic Respiration (Glycolsysis/Link/Krebs/Oxidative Phosphorylation) Flashcards
Where does glycolysis occur?
Cyptoplasm
Describe the stages of glycolysis
1) Glucose is phosphorylated, by 2ATP—>2ADP, forming 2x triose phosphate (3C)
2) Triose phosphate is oxidised by two molecules of NAD which becomes 2x NADH, forming the final product of 2x pyruvate (3C)
3) 4 ADP +Pi is converted into 4ATP
What’s the net gain of ATP in glycolysis?
2 ATP (4 in total but 2 used up)
Name the products of glycolysis
2 pyrvuate, 2ATP, 2NADH
Name the first stage of aerobic respiration
Glycolysis
Name the second stage of aerobic respiration
Link Reaction
Where does the link reaction occur?
Mitochondrial matrix
What product enters the link reaction that was made in glycolysis?
Pyruvate (3C)
Describe the stages of the link reaction
1) Pyruvate is decarboxylated producing one a molecule of CO2
2) Pyruvate loses a hydrogen to form acetate, reducing NAD to NADH
3) Acetate combines with CoA to form acetyl CoA (2C)
how much ATP is produced in the link reaction?
None
How many times does the link reaction occur per glucose molecule?
Twice as two pyruvate made for every glucose molecule (2x CO2 produced, 2x NADH, 2 acetyl CoA)
What type of product is CO2 in the Link Reaction?
It’s a waste product
Where does acetyl CoA go after link reaction?
Enters the Krebs Cycle
Where does the Krebs cycle take place?
Mitochondrial matrix
How many times does the Krebs cycle happen per glucose molecule?
Happens once per pyruvate and two pyruvate molecules produced in glycolysis so happens twice for every glucose molecule
- What product from the link reaction combines with another product to form citrate (6C)
Acetyl CoA (2C) combines with oxaloacetate (4C) to produce citrate (6C)
- Describe the second step of Krebs cycle
Citrate (6C) is decarboxylated, to produce a molecule of CO2 and dehydrogenated, to produce a molecule of NADH.
A 5C molecule is produced.
- Describe the third stage in Krebs cycle
The 5C molecule is decarboxylated to produce CO2 and dehydrogenated to produce one molecule of FADH and two of reduced NADH.
ATP is also produced from the transfer of a phosphate group (from an intermediate) to ADP.
Name the products of Krebs cycle for one turn
2x CO2 (waste) 3x NADH (OP) 1x FADH (OP) 1x ATP (energy) Oxaloacetate (Krebs) 1x CoA (used in link)
What does OP have to be in presence of to work?
Oxygen as it’s needed as the final electron acceptor
Where does OP take place?
Inner mitochondrial membrane
Where do the protons and electrons come from for OP?
NADH and FADH donate hydrogen atoms which are split into protons and electrons
Describe the stages of OP
1) Electrons move along the electron transport chain and are accepted by the ‘final electron acceptor’ of oxygen with combines with protons and electrons to form water
2) Meanwhile electron movement provides energy for protons to be pumped across the mitochondrial membrane, from the matrix into the inter membrane space. This provides an electrochemical gradient.
3) The protons diffuse through ATPase (facilitated diffusion) to matrix which provides energy to convert ADP + Pi into ATP, known as chemiosmosis
What’s the waste product of OP
Water
What happens to NAD and FAD at end of OP?
Put back into Krebs cycle
How many ATP are made from one molecule of NADH?
3 ATP
How many ATP are made from one molecule of FADH?
2ATP
How many ATP molecules produced per glucose?
38
