Energy (Krebs etc ) please finnish Flashcards
How do cells obtain energy?
Cells can get energy from carbohydrates, Proteins and lipids
Nutrients undergo biochemical reactions, known collectively as metabolism
These processes are:
Anabolic processes- create larger molecules. Require energy. Example: bonding of amino acids to make proteins,
Catabolic processes- larger molecules are broken down to smaller ones. Release energy . Example: glucose breakdown
Cells conserve some of the energy to generate a metabolic currency (ATP)
How do cells generate energy from nutrients?
Glycolysis- anaerobic break down of glucose to pyruvate. Small amount of ATP generated by substrate level phosphorylation
Krebs’ Cycle- oxidation of Acetyl CoA to CO. generates coenzymes: NADH and FADH2
Oxidative phosphorylation- transduction of energy derived from fuel oxidation to high energy phosphate. Generates large amounts of ATP.
where does glycolysis occur
in cytosol
is glycolysis anaerobic or aerobic
Aerobic
what are the products of glycolysis
2 ATP, 2 NADH, 2 Pyruvate
What is the rate limiting enzyme in glycolysis?
Phosphofructokinase-1
Draw a glycolysis diagram with the words or each product + enzymes involved
Compare to diagram from ppt
In glycolysis ATP: is an inhibitor of _______
phosphofructokinase-1
in glycolysis what are the regulators of Phosphofructokinase-1
ATP, AMP, Citrate, fructose,2,6,bisphasphate
In glycolysis how does AMP regulate PFK1
Increasing levels of AMP from used up ATP relieves the inhibition of PFK-1 by ATP. i.e activates PFK1
In glycolysis how does citrate regulate PFK1
first product of kreb’s also allosterically inhibits PFK-1.
Increase citrate levels is a signal that the cycle does not need more fuel.
Which 2 cellular conditions may the fate of pyruvate fall under
Aerobic and anaerobic respiration
what is the fate of pyruvate under aerobic conditions
Pyruvate enters mitochondria converted to Acetyl CoA and CO2 by Pyruvate Dehydrogenase.
Acetyl CoA can enter Krebs for more energy production
what is the fate of pyruvate under anaerobic conditions
Lactate formation, catalysed by lactate dehydrogenase
Regeneration on NAD+
Draw anaerobic and aerobic fates of pyruvate
compare to ppt
is aerobic conversion of pyruvate
a)reversible
b)irreversable
b
Where does Krebs occur and under which conditions
mitochondrial matrix
aerobic conditions
what is the first stage of krebs
Acetyl CoA combines with oxaloacetate
forms Citrate using citrate synthase
What is the second stage of Krebs
Citrate is converted to Isocitrate by aconitase
What is the third stage of krebs
Isocitrate is oxidized and decarboxylated by isocitrate dehydrogenase to form alpha-ketoglutarate
What is the 4th stage of Krebs
alpha-ketoglutarate converted to succinyl CoA by alpha-ketoglutarate dehydrogenase
What is the 5th stage of Krebs
Succinyl CoA converted to Succinate as CoA is subtracted and GDP is phosphorylated by succinyl CoA synthetase
Generates ATP through substrate level phosphorylation
What is the 6th stage of krebs
Succinate oxidized to Fumarate by succinate dehydrogenase ( complex II part of the ETC), reducing FAD in process
What is the 7th stage in Krebs
Fumarate converted to Malate by fumarase, adding H20 in the process
What is the 8th(final) stage of Krebs
Malate converted back to oxaloacetate by malate dehydrogenase
further oxidized, and NAD+ is reduced.
What is the total energy gain from 1 cycle of krebs
2 ATP
2 FADH
6NADH
Where does oxidative phosphorylation occur and under which conditions
mitochondrial membrane
Aerobic conditions
