2.8 Flashcards
Cell respiration
Cell respiration is the controlled release of energy from organic compounds to produce ATP
Main organic compound used in cell respiration
The main organic compound used for this process is carbohydrates (glucose), although lipids and proteins can also be digested
There are two main types of cell respiration:
Anaerobic and Aerobic
Anaerobic cell respiration
Anaerobic respiration involves the partial breakdown of glucose in the cytosol for a small yield of ATP
Aerobic cell respiration
Aerobic respiration utilises oxygen to completely break down glucose in the mitochondria for a larger ATP yield
ATP (adenosine triphosphate) is…
a high energy molecule that functions as an immediate source of power for cell processes
One molecule of ATP contains three…
covalently linked phosphate groups – which store potential energy in their bonds
When ATP is hydrolysed it forms?
ADP + Pi, the energy stored in the phophate bond is released to be used by the cell
Cell respiration uses energy stored in…
organic molecules to regenerate ATP from ADP + Pi (via oxidation)
glycolysis
glycolysis begins with the anaerobic breakdown of glucose in the cytosol. Both anaerobic and aerobic respiration pathways begin with this.
Glycolysis breaks down glucose (6-C) into
two molecules of pyruvate (3C), and also produces:
- Hydrogen carriers (NADH) from an oxidised precursor (NAD+)
- A small yield of ATP (net gain of 2 molecules)
Anaerobic respiration proceeds in the absence of…
oxygen and does not result in the production of any further ATP molecules
pyruvate in animals
In animals, the pyruvate is converted into lactic acid (or lactate)
pyruvate in plants and yeast
In plants and yeasts, the pyruvate is converted into ethanol and carbon dioxide
The purpose of anaerobic respiration is to…
restore stocks of NAD+ – as this molecule is needed for glycolysis
- By restoring stocks of NAD+ via anaerobic pathways, the organism can continue to produce ATP via glycolysis