5A - Respiration Flashcards
How many types of respiration are there?
2
What are the two types of respiration?
Aerobic and anaerobic
What do both types of respiration produce?
ATP
What stage do both types of respiration start with?
Glycolysis
What is the main purpose of glycolysis?
To make pyruvate from glucose
What does glycolysis involve?
Splitting one molecule of glucose (with 6 carbons - 6C) into two smaller molecules of pyruvate (3C).
Where does glycolysis happen?
Cytoplasm.
What is glycolysis?
The first stage of respiration (aerobic and anaerobic).
Is glycolysis aerobic or anaerobic?
Anaerobic - so doesn’t need oxygen to take place.
How many stages are there in glycolysis?
2
What are the 4 main stages of respiration?
Glycolysis
Link reaction
Krebs cycle
Oxidative phosphorylation
How many main stages of aerobic respiration are there?
4
What are the 2 stages of glycolysis?
Phosphorylation and oxidation.
What happens in the first stage of glycolysis?
- Glucose is phosphorylated using a phosphate from a molecule of ATP. This creates one molecule of glucose phosphate and one molecule of ADP.
- ATP is then used to add another phosphate, forming hexose bisphosphate.
- Hexose bisphosphate is then split into 2 molecules of triose phosphate.
What happens in the second stage of glycolysis?
- Triose phosphate is oxidised (loses hydrogen), forming 2 molecules of pyruvate.
- NAD collects the hydrogen ions, forming 2 reduced NAD.
- 4ATP are produced, but two were used up in stage one, so there’s a net gain of 2ATP.
What is the second stage of glycolysis called?
Oxidation
What is the first stage of aerobic respiration called?
Glycolysis
What is the second stage of aerobic respiration called?
Link reaction
What is the third stage of aerobic respiration called?
Krebs cycle
What is the fourth stage of aerobic respiration called?
Oxidative phosphorylation
What is the net gain of ATP in glycolysis?
2ATP
What do NAD and FAD do?
Transport hydrogen between molecules (so they can reduce various substances).
What does coenzyme A do?
Transfers acetate between molecules.
What is pyruvate converted to in anaerobic respiration after glycolysis?
Ethanol or lactate.
What happens to the two molecules of reduced NAD produced in glycolysis in aerobic respiration?
They go to oxidative phosphorylation.
What happens to the two pyruvate molecules produced in glycolysis in aerobic respiration?
They are actively transported into the matrix of the mitochondria for the link reaction.
In what is pyruvate converted into ethanol in anaerobic respiration?
In plants and yeast (alcoholic fermentation).
In what is pyruvate converted into lactate in anaerobic respiration?
Animal cells and some bacteria (lactate fermentation).
What converts the pyruvate produced in glycolysis into ethanol/lactate in anaerobic respiration?
Reduced NAD.
What does the production of ethanol/lactate do?
Regenerates oxidised NAD.
What does the production of ethanol/lactate mean can happen?
Means glycolysis can continue even when there isn’t much oxygen around, so a small amount of ATP can still be produced to keep some biological processes going.
What is the second part of aerobic respiration?
The link reaction.
What is the main thing that happens in the link reaction?
Pyruvate is converted to acetyl coenzyme A.
What are the steps to the link reaction?
1) Pyruvate is decarboxylated (one carbon is removed from pyruvate in the form of CO2).
2) Pyruvate is oxidised to form acetate and NAD is reduced to form reduced NAD.
3) Acetate is combined with coenzyme A (CoA) to form acetyl coenzyme A (acetyl CoA).
4) No ATP is produced in this reaction.
How much ATP is produced in the link reaction?
None.
How often does the link reaction occur?
Occurs twice for every glucose molecule.
Why does the link reaction happen twice for every glucose molecule?
Because two pyruvate molecules are made for every glucose molecule that enters glycolysis meaning that the link reaction and the third stage ( the Krebs cycle) happen twice for every glucose molecule.
How many molecules of acetyl coenzyme A go into the Krebs cycle for each molecule of glucose?
2
How many molecules of CO2 are released as a waste product of respiration for each molecule of glucose?
2
How many molecules of reduced NAD are formed and go to the last stage (oxidative phosphorylation) for each molecule of glucose?
2