CATABOLIC CORE OF METABOLISM

when does glycolysis occur

most of the time in tissues

what is glycolysis controlled by

mass action (substrates and products) and allosteric regulation of enzymes

which enzyme which converts blood glucose into glucose 6-P

hexokinase

which enzyme converts fructose 6-P into fructose 1,6-BP

PFK (Phosphofructokinase)

which enzyme converts PEP into pyruvate

pyruvate kinase

What is hexokinase inhibited by?

inhibited by glucose 6 phosphate

what is PFK inhibted and stimulated by

Inhibited: ATP,Citrate,H+

Stimulated: AMP

what is pyruvate kinase inhibited by and stimulated by

Inhibited: ATP

Stimulated: Fructose 1,6-BP

what is pyruvate converted into

acteyl CoA

what happens to pyruvate in anaerobic conditions

its converted into lactate as the ETC cant accept any more electrons

what is the link reaction

pyruvate converted into acetyl CoA

(Connects glycolysis to CAC)

which enzyme is involved in the link reaction

pyruvate dehydrogenase

what inhibits and stimulates pyruvate dehydrogenase

Inhibits: ATP and NADH and Acetyl CoA

Stimulates: Pyruvate, Calcium and Insulin

what is produced during the krebs cycle

1 CoA

3 NADH

1 FADH2

2 Co2

2 H+

what happens during the electron transport chain

NADH binds to complex 1 and donates 2 electrons, the energy transferred is used to pump 4 protons into the intramembranous space, shuttle passes the 2 electrons to another complex and 2 protons are pumped across, which then passes the 2 electrons to another shuttle which is passed along to the last complex where oxygen comes along with 2 protons and the 2 electrons are added resulting in water and 4 more protons are pumped across at the last complex

This created a gradient to generate the ATP

at the end of the ETC what molecule is found

ATP synthase

how is ATP synthase involved in the formation of ATP

3 protons move through the complex, this rotates a 1/3 of a turn and each 1/3 of a turn results in the formation of an ATP from ADP and Pi

Actually need 4 protons as it needs an extra proton to move the ATP out of the mitochondria into the cytosol for it to be used in another process

what can the proton gradient be disrupted by

uncoupling agents which generate heat

what does non- shivering thermogenesis involve

hibernating animals, some neonates) - brown fat tissue has lots of mitochondria to produce lots of thermogenesis

what protein is found in non shivering thermogenesis and what does it do

Thermogenin - acts to transfer protons down the conc gradient form the cytosol to the mitochondrial matrix and heat is produced. - wasting energy by speeding up metabolism

what does DNP do to the the electochemical gradient

DNP can carry protons over the inner mitochondrial membrane and thereby dissipate the proton motive force. (membrane becomes permeable to protons) no ATP is produced as there is no gradient to form the ATP of hydrogen (protons)

Electro and chemical gradient is dissipated by DNP but with valinomycin on the electro gradient is affected and so some ATP is still produced but the amount is reduced