2. Glycolysis: Aerobic and Anaerobic respiration

Where does glycolysis happen?

In the cytoplasm of cells.

What type of process is glycolysis?

Anaerobic.

1. What is gaining hydrogen/ electrons.

2. What is losing hydrogen/ electrons.

1. Reduction

2. Oxidation

What are the two stages of glycolysis?

1. Phosphorylation

2. Oxidation

What is the net gain of glycolysis?

2 ATP, 2 Reduced NAD, 2 pyruvate.

Describe the first stage of glycolysis: Phosphorylation - 4

• Glucose is phosphorylated using a phosphate from a molecule of ATP.

• This created 1 molecule of glucose phosphate and 1 molecule of ADP.

• ATP is then used to add another phosphate, forming hexose biphosphate.

• hexose biphosphate is then split into 2 molecules of triose phosphate.

Describe the second stage of glycolysis: Oxidation

• Triose phosphate is oxidised (loses hydrogen), forming 2 molecules of pyruvate.

• NAD collects the hydrogen ions, forming 2 reduced NAD.

• 4 ATP are produced, but 2 were used up in stage one, so there’s a net gain of 2 ATP.

Draw a diagram summing up glycolysis.

in book for now

Where does the two reduced NAD go to?

Oxidative phosphorylation

Where does the 2 pyruvate go and what is it used for?

Actively transported into the mitochondrial matrix for use in the link reaction.

Where does the 2 ATP go?

used for energy

What happens to the pyruvate produced in glycolysis during anaerobic respiration?

This is converted into ethanol (alcoholic fermentation) or lactate (lactate fermentation), using reduced NAD.

Where does alcoholic fermentation occur?

In plants and yeast

Write the 3 processes of alcoholic fermentation.

pyruvate → (release of CO2) → ethanal → (reduced NAD reduces the ethanal to release NAD) → ethanol.

Where does lactate fermentation occur?

Animal cells and some bacteria

Write the 2 processes of lactate fermentation.

pyruvate → (reduced NAD to NAD) → lactate (lactic acid)

How does anaerobic respiration work?

The production of lactate or ethanol regenerates oxidised NAD. This 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.