Topic 5- Energy transfers in organism Flashcards
where does glycolysis occur?
in the cytoplasm
what two types of respiration does glycolysis occur in?
aerobic and anaerobic
describe the process of glycolysis
1) 2 molecules of ATP hydrolysed to produce 2 ATP and 2 inorganic phosphate
2)phosphorylation of glucose to glucose phosphate
3)glucose phosphate split into triose phosphate
4)triose phosphate oxidised producing pyruvate
5)co enzyme NAD reduced to produce NADH
6)4 molecules of ATP produced through substrate-level phosphorylation
what reactions make up the process of aerobic respiration?
glycolysis, link reaction, krebs cycle, oxidative phosphorylation
what is the net gain of ATP in glycolysis?
2
where does the link reaction occur?
mitochondrial matrix
describe the process of the link reaction
1) pyruvate actively transported into the mitochondrial matrix
2)pyruvate is converted into acetate
3)molecule of carbons dioxide is produced through pyruvate decarboxylation and pyruvate is oxidised
4)hydrogen lost reduces NAD to NADH
5)acetate + CoA produced acetyl CoA
what is the overall equation for the link reaction?
pyruvate + NAD +CoA —>CO2 + NADH+ acetyl CoA
where does the krebs cycle occur?
mitochondrial membrane
how many times does the krebs cycle repeat?
twice
what is the net gain of ATP from the krebs cycle?
2
describe the krebs cycle
1)acetyl CoA loses the CoA and binds to oxaloacetate to form citrate (6c)
2)citrate is decarboxylated twice producing 2 carbon dioxide molecules
3)citrate is also dehydrogenated twice producing 2 NADH
4)the 4c compound created undergoes substrate level phosphorylation producing ATP
5)co enzymes, NAD and FAD, are reduced
6) cycle repeats again for each molecule of glucose
where does oxidative phosphorylation occur?
between the matrix and inter membrane space
how much ATP is produced from oxidative phosphorylation?
over 30 molecules
describe the process of oxidative phosphorylation
1)NADH and FADH travel towards the inner mitochondrial membrane
2)electrons donated to proteins in the membrane, producing NADH, FAD and protons when NADH and FADH2 are oxidised
3)electrons move along electron transfer chain through a series of redox reactions
4)as they travel, electrons provide the proteins with energy
5)energy is used to transport protons from the matrix to inter membrane space through active transport
6)this maintains a proton gradient
7)electrons at the end of the chain react with oxygen and protons to produce water
8)oxygen is known as the final electron acceptor
9)protons in the inter membrane space diffuse back into the matrix via ATP synthase in a process known as chemiosmosis
10)supplies ATP synthase with energy which is used to catalyse the production of ATP
where does the whole process of anaerobic respiration occur?
in the cytoplasm
what happens after glycolysis when anaerobic respiration occurs in animals?
lactate fermentation
what happens after glycolysis when anaerobic respiration occurs in yeast/plants?
ethanol fermentation
describe ethanol fermentation
1)pyruvate decarboxylated to form ethanal, losing carbon dioxide
2)NADH oxidised to NAD, reducing the ethanal to ethanol as it gains the hydrogen
3)the regenerated NAD is repeatedly used in glycolysis so ATP can continue to be made
describe lactate fermentation
1)NADH oxidised to NAD
2)pyruvate gains hydrogen reducing it to lactate
3)regenerated NAD repeatedly used in glycolysis so that ATP can continue to be made