Summary Energy for Biology Processes

TOPIC 5 notes
5.1 Aerobic respirati on

i Know that cellular respiration yields ATP which is used as a source of energy for metabolic
reactions, and the process also generates heat.

C6H12O6 + 6O2  6CO2 + 6H2O

ii Know the different stages in aerobic respiration, including:

Glycolysis in the cytoplasm

5.2 Glycolysis

i Understand the conversion of monosaccharides to pyruvate during glycolysis in the cytoplasm,
including:

 the phosphorylation of hexose molecules by ATP
 breakdown to glycerate 3-phosphate (GP)
 production of reduced coenzyme (NADH) and ATP (details of intermediate compounds and
other reactions are not required).




SIMPLIFIED

, STAGE 1: substrate level phosphorylation

a) glucose is phosphorylated by adding 2 phosphates from 2 molecules of ATP molecules
b) 2 molecules of triose phosphate are created and 2 molecules of ATP are used

STAGE 2: oxidative conversion

a) Each triose phosphate is oxidised, forming two molecules of pyruvate
b) Each NAH+ collects the H forming reduced 2NADH
c) 4 ATP produced, 2 used at start so net product of 2



5.3 Link reaction and Krebs cycle

i Know that the link reaction and Krebs cycle take place in the mitochondrial matrix.

ii Understand that during the complete oxidation of pyruvate the events of the link reaction and the
Krebs cycle result in the removal of carbon atoms to produce:

 carbon dioxide
 reduced coenzyme (NADH)
 ATP (detailed knowledge of the intermediate compounds in the Krebs cycle is not required).

Coenzymes are organic non-protein molecules that bind to enzymes to allow it to carry out its
function

Link reaction

Both the link reaction and
Krebs cycle occur in the
mitochondrial matrix