Respiration

Question 1

products of glycolysis

Answer 1

2 pyruvate molecules
2 NADH2 molecules
overall net of 2 ATP molecules

Question 2

where does glycolysis occur?

Answer 2

the cytoplasm of all living cells

Question 3

does glycolysis require oxygen?

Answer 3

no

Question 4

Outline the link reaction

Answer 4

pyruvate molecule is converted to acetate by oxidative decarboxylation.
the acetate combines with coA to form acetylcoA which then travels to the Krebs Cycle

Question 5

where does the link reaction occur?

Answer 5

the matrix of the mitochondria

Question 6

does the link reaction require oxygen?

Answer 6

yes

Question 7

outline key steps of Krebs Cycle

Answer 7

acetate is carried intot he krebas cycle where it joins onto oxaloacetate (4C) to form citric acid (6C). via a series of oxidation-reduction reactions, the citric acid is converted to oxaloacetate which will join onto a new acetate molecule to restart the cycle

Question 8

what are the products of ONE turn of the Krebs Cycle?

Answer 8

one turn generates; 
3 NADH2 molecules 
1 FADH2 molecule 
1 ATP molecule 
2 CO2 molecules

Question 9

where does the Krebs cycle occur?

Answer 9

in the matrix of the mitochondria

Question 10

siginificance of the Krebs cycle (4)

Answer 10

1- breaks down macromolecules into smaller ones (pyruvate into carbondioxide)
2-produces H2 carried by NAD to the electron transport chain and provides enough energy for oxidative phosphorylation, lading to production of ATP that provides metabolic energy for the cell
3-regenerates the 4C molecule, oxaloacetate, that binds with acetylcoenzymeA, which would otherwise accumulate
4-source of intermediate compounds used by cells to produce other important substances such as fatty acids,AA,chlorophyll

Question 11

outline the process of oxidative phosphorylation

Answer 11

NADH2 donates the hydrogen its carrying and it returns to the Krebs cycle
hydrogen split into protons and electrons
energy is released- used for ATP generation
protons pumped (into intermembranal space)
sets up proton gradient
protons diffuse down the conc gradient
protons accumulate in the intermembraneous space so they flow out of the protein channel ATPsynthase
this flow of hydrogens causes ATPsynthase to change shape to catalyse ATP synthesis
electrons combine with protons and oxygen to form water- oxygen is the final electron acceptor. this is catalysed by cytochrome C?

Question 12

where does oxidative phosphorylation occur?

Answer 12

occurs in the cristae
protons go from the matrix of the mitochondria, through the inner membrane, accumulate in the intermembraneous space and then they flow back into matrix through ATP synthase

Question 13

products of oxidative phosphorylation

Answer 13

34 ATP molecules

Question 14

distinguish between an obligate anaerobe and a facultative anaerobe

Answer 14

obligate anaerobe- respires only anaerobically

facultative- can respire either anaerobically or aerobically eg yeast