PH1123 - Energy and metabolism Flashcards
(42 cards)
what is the universal energy molecule?
- ATP
what is the structure of ATP?
- adenine
- ribose
- 3 phosphate groups
what bonding is present in ATP? (2)
- phosphate ester bonds
- phosphoanhydride bonds
what releases energy in ATP?
- hydrolysis of the phosphoanhydride bonds
what are the factors that result in the high energy release during the hydrolysis of phosphoanhydride bonds? (3)
- decrease repulsion between phosphate groups helps drive hydrolysis
- increased resonance in product
- electrostatic repulsion between negative charges in ATP
what are the different stages of energy production? (3)
- stage 1; no useful energy generated
- stage 2; small amounts of ATP generated (anaerobic no oxygen)
- stage 3; majority of ATP production aerobic with oxygen)
what is the energy supply for most organisms?
- metabolism of glucose and other sugars
why is the metabolism of fats and proteins important?
- important energy production when the supply of glucose and other sugars are limited
what is the initial stage of the metabolism of glucose (respiration) called?
- glycolysis
where does glycolysis take place ?
cytoplasm
what are the different reaction types in glycolysis? (6)
- type 1; phosphoryl transfer
- type 2; phosphoryl shift
- type 3; isomerisation
- type 4; dehydration
- type 5; aldol cleavage
- type 6; oxidation
what are the two parts that glycolysis is divided into? (2)
- the first reactions with 6 carbon units which requires energy (hexose stage)
- the reaction on the 3 carbon units which provides energy (triose stage)
what is the net output of ATP in glycolysis?
- 2 molecules of ATP
what does glycolysis produce?
- pyruvate x2
what are the fates of pyruvate? (3)
- conversion to acetyl coenzyme A
- conversion to lactate
- conversion to ethanol
what is acetate coenzyme A?
- compound used in the citric acid cycle and electron transport chain
where does formation of acetyl coenzyme A occur?
- mitochondira matrix
what enzymes is required for the conversion of pyruvate to acetyl CoA?
- pyruvate dehydrogenase
what enzymes is required for the conversion of pyruvate to lactate?
- lactate dehydrogenase
What are the bonds the hold the phosphates together called and what is special about them?
Phosphoanhydride bonds. They are unstable so are easily hydrolysed which generates a lot of energy.
When do organisms start to metabolise fats and proteins?
When the supply of glucose and other sugars is limited.
What are some important points about glycolysis?
Takes place inside of the cytoplasm, requires no oxygen and generates two molecules of NADPH and a NET of 2 ATP
What are the energy requiring steps in glycolysis?
Glucose to glucose 6 phosphate and
fructose 6 phosphate to fructose 1,6 bisphosphate.
What is the role of hexokinase?
Phosphorylates glucose to glucose 6 phosphate