Photosynthesis and Respiration- Aerobic Respiration Flashcards
What is the process of the link reaction?
- Pyruvate is decarboxylated
- Pyruvate is oxidised to form acetate and NAD is reduced to form reduced NAD
- Acetate is combined with CoA to form acetyl COA
How many times does the link reaction occur for every glucose molecule?
Twice
Where does the Krebs cycle take place?
In the matrix of the mitochondria
What is the process of the Krebs cycle?
- Acetyl CoA combines with oxaloacetate (4C) to form citrate (6C)
- Decarboxylation occurs to make 6C molecule a 5C molecule and dehydrogenation occurs, and the hydrogen is used to produce reduced NAD from NAD
- 5C molecule then converted to a 4C molecule (decarboxylation) and dehydrogenation occurs, and a 1 molecule of reduced FAD and 2 molecules of reduced NAD are produced
- ATP is produced by the direct transfer of a phosphate group from an intermediate compound to ADP
- Citrate has now been converted into oxyloacetate
What are the products of the Krebs cycle?
1 coenzyme A, oxaloacetate, 2 CO2, 1 ATP, 3 reduced NAD, 1 reduced FAD
Where does 1 coenzyme A go?
Reused in the next link reaction
Where does oxaloacetate go?
Regenerated for use in the next Krebs cycle
Where does 2 CO2 go?
Released as a waste product
Where does 1 ATP go?
Used for energy
Where does 3 reduced NAD go?
To oxidative phosphorylation
Where does 1 reduced FAD go?
To oxidative phosphorylation
What is oxidative phosphorylation?
The process where the energy carried by electrons, from reduced coenzymes is used to make ATP
What does oxidative phosphorylation involve?
The electron transport chain and chemiosmosis
What happens to the hydrogen atoms in oxidative phosphorylation?
Hydrogen atoms are released from reduced NAD and reduced FAD as they’re oxidised to NAD and FAD, and the H atoms split into protons and electrons
What happens to the electrons in oxidative phosphorylation?
They move down the electron transport chain, losing energy at each carrier
How is the energy used in oxidative phosphorylation?
It is used by the electron carriers to pump protons from the mitochondrial matrix into the intermembrane space
What happens to the concentration of protons in oxidative phosphorylation?
It is higher in the intermembrane space than in the mitochondrial matrix which forms an electrochemical gradient
How do protons move in oxidative phosphorylation?
Down the electrochemical gradient, back across the inner mitochondrial membrane and into the mitochondrial matrix via ATP synthase- this drives the synthesis of ATP from ADP and inorganic phosphate
What is chemiosmosis?
The process of ATP production driven by the movement of H+ ions across a membrane
What happens in the mitochondrial matrix at the end of the transport chain in oxidative phosphorylation?
The protons, electrons and O2 combine to form water- oxygen is the final electron acceptor
