3.3 Respiration Flashcards
(27 cards)
What is oxidative phosphorylation?
When ATP is synthesises through either a redox or oxidation reaction, as electrons are passed through an ETC. It requires oxygen.
Where does oxidative phosphorylation occur?
Within the inner mitochondrial membrane
What is substrate level phosphorylation?
When a phosphate group is transferred directly to ADP to synthesise ATP. Does not require oxygen.
What is an obligate aerobe?
An organism that relies on aerobic respiration to synthesise ATP, can not respire without the presence of oxygen.
What is an obligate anaerobe?
An organism that can only respire anaerobically and can not live in conditions present with oxygen.
What is a facultative anaerobe?
Organisms that usually respire aerobically but can switch to anaerobic respiration if necessary.
Where does glycolysis occur and in what type of respiration?
Occurs in cytoplasm of both anaerobic and aerobic respiration.
Outline the stages of glycolysis?
1) Glucose is phosphorylysed ( the addition of 2 phosphate groups) by two molecules of ATP to create glucose phosphate, this is much more reactive.
2) The glucose phosphate then splits into two triose phosphates.
3) The triose phosphates are each converted into pyruvate by dehydrogenation. The triose phosphates lose a hydrogen each which is accepted by NAD to create NADH. This redox reaction generates 2 ATP molecules.
What are the products of Glycolysis?
- Pyruvate
- ATP
- NADH
What is the NET gain of ATP and NADH in glycolysis?
- 2 ATP
- 2 NADH
What products are used in the link reaction?
- Pyruvate
Where does the link reaction occur?
Within the mitochondrial matrix
Outline the stages of the link reaction.
- Pyruvate (3C) enters the mitochondrial matrix and is oxidised to acetate (2C) to release hydrogen to create NADH and CO2.
- Co enzyme A from the Krebs cycle then reacts with Acetate to create AcetylCoenzymeA
Outline the stages of the Krebs cycle
1) AcetylCoenzyme A reacts with a 4C compound to create a 6C Citric acid.
2) The 6C Citric acid is then dehydrolysed and decarboxylates to create a 5C compound. This generates NADH and CO2.
3) The 5C compound then dehydrogenates and decarboxylates to create a 4C compound to create NADH, ATP and C02.
4) The 4C compound dehydrogenates to create FADH.
5) The 4C compound dehydrogenates again to create NADH.
What are the products and values of the Krebs cycle?
- 3NADH
- 1FADH
- 1 ATP
- 2 CO2
How many times does dehydrogenation occur in the Krebs cycle?
4
How many times does decarboxylation occur in the Krebs cycle?
2
How many molecules of ATP does one NAD produce?
3 ATP, as its associated with 3 proton pumps.
How many molecules of ATP does one FAD produce? Why?
2 ATP, as its associated with 2 proton pumps.
Where is the ETC located?
Within the cristae of mitochondria
How would the presence of cyanide affect the ETC?
Cyanide is a non competitive inhibitor, it stops oxygen receiving the electrons from the last proton pump causing a build up of electrons so the ETC can no longer work.
If oxygen is not present how would this affect respiration?
Only glycolysis could occur, the Krebs cycle and link reaction would not.
How does anaerobic respiration occur in animals?
Glycolysis still continues but without the presence of oxygen pyruvate becomes the last hydrogen acceptor. Lactic acid is formed.
How does anaerobic respiration occur in yeast?
Glycolysis occurs and pyruvate is decarboxylated forming ethanal and releasing carbon dioxide. NADH releases its electrons to ethanal to produce ethanol.
