5.8 Respiration Flashcards
Why do organisms need to respire?
- Active transport
- Anabolic reactions
- Movement
- Mitosis
- Exocytosis
- Endocytosis
(AAMMEE)
Describe the structure of the mitochondria
- Mitochondrial DNA
- Matrix
- Inner mitochondrial membrane (folded) including the Cristae
- Outer mitochondrial membrane
- Ribosomes
Describe the process of respiration
respiration is the process which allows cells to produce ATP from glucose or other complex organic molecules.
What are the four stages of aerobic respiration?
Stage 1 - glycolysis
Stage 2 - the link reaction
Stage 3 - the Krebs cycle
Stage 4 - oxidative phosphorylation
where does glycolysis occur?
In the cytoplasm of a respiring cell
where does the link reaction occur?
In the mitochondrial matrix
where does the Krebs cycle occur?
In the mitochondrial matrix
Where does oxidative phosphorylation occur?
in the Cristae of the inner mitochondrial membrane
explain the process of glycolysis.
- Glucose phosphorylation from Glucose to Hexose Bisphosphate by two ATP molecules
- Splitting of hexose bisphosphate into 2 triose phosphate
- Triose phosphates are oxidised by NAD to form NADred and two ATP molecules per triose phosphate are made. Substrate level phosphorylation.
What are the products of glycolysis?
:
- 2 net ATP
- 2 x pyruvate
- 2 x NADred
explain the process of the link reaction
- Pyruvate is decarboxyalted (- CO2) and reduced by NAD to make acetyl and NADred
- Acetyl combines with coenzyme A (CoA) to form acetyl-CoA.
What are the products of link reaction?
:
- 2 x CO2
- 2 x NADred
- 2 x acetylCoA
Explain the process of the Krebs cycle
- AcetylCoA releases acetyl (2C) which combines with oxaloacetate (4C) to form citrate (6C)
- Citrate undergoes, decarboxylation and reduction by NAD. This forms at 5C compound
- The 5C compound undergoes decarboxylation and reduction too to form a 4C compound
- The 4C compound undergoes substrate level phosphorylation to produce ATP from ADP + Pi
- The 4C compound then undergoes reduction by FAD and NAD to reform oxaloacetate.
What are the products of the Krebs cycle?
For every 2 turns
- 2 x ATP
- 6 x NADred
- 2 x FADred
- 4 x CO2
what is the electron transport chain?
(in respiration)
it’s a series of carrier proteins embedded in the membrane of the Cristae. They produce ATP by oxidative phosphorylation via chemiosmosis during aerobic respiration.
