respiration Flashcards
name the 4 stages in aerobic respiration
glycolysis, link reaction, krebs cycle, chemiosmotic theory
where does glycolysis happen?
in the cytoplasm
what is the process of glycolysis
- atp provides energy to glucose = more reactive
- atp -> adp, donates 2 phosphates to make phosphorylated glucose
- splits into 2 triosephosphate
- co enzyme nad pulls 1 hydrogen from each TP (becomes NADH)
- 4 ADPs remove phosphates from TP, becoming ATP
- leaves you with 2 pyruvate
what are the products of glycolysis?
2 x pyruvate
ALSO: ADP, ATP, NADH
where does the link reaction occur?
in the matrix (mitochondria)
explain the process of the link reaction
- 2 pyruvate transported through a protein channel in mitochondrial membrane
- NAD removes a hydrogen from pyruvate, making NADH & oxidised pyruvate
- co2 is removed from oxidised pyruvate (decarboxylation)
- co enzyme A (coA) is added which binds to the 2 2C compounds
- forms 2 acetyl coA
what are the products of the link reaction?
2 acetyl coA
ALSO: NADH, CO2
where does the krebs cycle occur?
in the matrix (mitochondria)
explain the process of the krebs cycle
- acetyl coA combines with a 2C sugar to form a 6C sugar
- NAD removes a hydrogen from 6C sugar (oxidising it and reducing NAD — NADH)
- co2 is removed - 6C is decarboxylised, becomes 5C sugar
- 2 NAD and FAD further oxidise 5C sugar (becoming 2x NADH + 2H and FADH + H)
- this oxidisation produces energy to add a phosphate from ADP to form ATP
- 5C sugar is decarboxylated to form a 4C sugar
- 4C sugar combines with acetyl coA
what are the products of the krebs cycle?
CO2, NADH + H, ATP, FADH + H
where does chemiosmotic theory happen?
in the membrane between the matrix and the intermembranal space
explain the process of chemiosmotic theory
- NADH arrives from krebs at first protein complex 1
- NADH oxidised back to NAD, releasing 2 electrons and protons
- electrons taken up by next protein and travel along the electron transport chain
- protein gaining electrons produces energy
- used to pump through protons into the inter membrane space
- 2 electrons associate with oxygen to form water
- end up with huge protein gradient
- pass through ATP synthase, producing enough energy to synthesise 3 ATP + protons
how is ethanol produced in plants & yeast during anaerobic respiration?
- pyruvate loses a molecule of co2
- accepts hydrogen from NADH to produce ethanol
- pyruvate + reduced NAD —> ethanol + co2 + oxidised NAD
how is lactate produced in animals during anaerobic respiration?
to make up oxygen debt:
• pyruvate takes hydrogen atoms from reduced NAD to form lactate
• pyruvate + reduced NAD —> lactate + oxidised NAD
how is energy from cellular respiration derived? (2 ways)
- substrate level phosphorylation in glycolysis & krebs
2. oxidative phosphorylation in electron transport chain
