12. RESPIRATION Flashcards
Explain why mitochondria have many cristae
To provide a large surface area for respiration enzymes for a faster rate of respiration
Write a full and balanced symbol equation for aerobic respiration
C6H12O6 + 6O2 → 6CO2 + 6H2O
Describe the function of a coenzyme
To transport particles from one reaction to another
Name the four stages of aerobic respiration
Glycolysis, link reaction, Kreb’s cycle and oxidative phosphorylation
Where does glycolysis occur?
Cytoplasm
Is glycolysis anaerobic or aerobic?
Anaerobic (because it does not require oxygen)
How is glucose phosphorylated to glucose phosphate in the first stage of glycolysis?
Two phosphate ions are added from two molecules of ATP
In glycolysis, glucose phosphate splits into two 3 carbon molecules. What are they called?
Triose phosphate
Describe how pyruvate is formed from triose phosphate in the final stage of glycolysis
Triose phosphate is oxidised by the removal of hydrogen atoms, which are used to reduce NAD to NADH.
How many molecules of ATP are required in the oxidation of triose phosphate to pyruvate in glycolysis?
2 ATP per triose phosphate, so 4 ATP in total
How many carbon atoms does each pyruvate molecule contain?
3 carbons each (6 carbons in total)
Name all the reactants of glycolysis
1 x Glucose, 2 x ATP, 4 x ADP, 2 x NAD
Name all the products of glycolysis
2 x Pyruvate, 2 x ADP, 2 x NADH, 4 x ATP
Why can we say there is a net production of 2 ATP in glycolysis?
Because two ATP are required for the phosphorylation of glucose phosphate, but four ATP are produced in the oxidation of Triose Phosphate
Where does the link reaction occur?
Mitochondrial matrix
Name the two reactions that happen to pyruvate when it is converted to acetate?
Oxidation and Decarboxylation
Describe how pyruvate is oxidised to acetate in the link reaction?
Pyruvate is oxidised through the removal of hydrogen atoms which are used to reduce NAD to NADH
Describe the decarboxylation of pyruvate to acetate
A carbon atom is removed from pyruvate and is used to produce one molecule of carbon dioxide
How many carbon atoms does acetate contain?
Two
Desribe how acetate is converted to acetyl coenzyme A in the final stage of the link reaction
Acetate and coenzyme A are combined to form Acetyl Coenzyme A
Name all the reactants of the link reaction per pyruyvate molecule
1 x Pyruvate, 1 x NAD, 1 x Coenzyme A
Name all the reactants of the link reaction per glucose molecule
2 x Pyruvate, 2 x NAD, 2 x Coenzyme A
Name all the products of the link reaction per pyruvate molecule
1 x Acetylcoenzyme A, 1 x Carbon Dioxide, 1 x NADH
Name all the products of the link reaction per glucose molecule
2 x Acetylcoenzyme A, 2 x Carbon Dioxide, 2 x NADH
Describe what happens to acetylcoenzyme A in the first stage of the Krebs cycle
Acetylcoenzyme splits into acetate and coenzyme A
Describe what happens to the coenzyme A produced from the splitting of acetylcoenzyme A in the Krebs cycle
It goes back to the link reaction to bond with another molecule of acetate
Describe what happens to the acetate produced from the splitting of acetylcoenzyme A in the link reaction
It bonds with a 4 carbon molecule to produce a 6 carbon molecule
In the krebs cycle, the 6C molecule undergoes a series of what type of reactions?
A series of redox reactions