REGULATIONS OF AEROBIC CATABOLIC PATHWAYS

Catabolism

Breaking complex molecules

Anabolism

Forming complex molecules

Phosphofructokinase

Main control in glycolysis

Pyruvate Dehydrogenase

Main control in Krebs cycle

Positive Feedback

• High levels of ADP 

• Activate phosphofructokinase which makes more ADP

Negative Feedback

• This enzyme has an allosteric site for ATP 

  • Excess ATP binds and inhibits the enzyme thus stopping glycolysis (too much ATP)

Citrate

• Too much citrate can also inhibit phosphofructokinase

• Stopping glycolysis from allowing to go any further

NADH

Excess NADH inhibits the enzyme pyruvate dehydrogenase so that the reaction that converts pyruvate into acetyl-CoA  is stopped, therefore slowing cellular respiration

Deamination

• The first step in protein catabolism, involving the removal of the amino group of an amino acid as ammonia 

  • The rest of the amino acid is used in cellular respiration (Eg: leucine is converted into acetyl-CoA)

  • Amino acids energy is transferred to ATP

Gluconeogenesis

• Process that converts glycerol (of triacylglycerol)  into glucose 

  • May also turn into DHAP and glyceraldehyde 3-phosphate 

  • Will be sent to glycolysis 

B-Oxidation

• The sequential removal of acetyl groups in the catabolism of fatty acids 

  • Acetyl groups combine with coenzyme groups to make acetyl-CoA

  • Coenzymes get reduced and provide energy (ATP)