respiration (key notes) Flashcards
max ATP produced in aerobic respiration is 32, but usually only 30 is produced. Why?
- energy lost as heat
- some ATP used in active transport of pyruvate into mitochondria
- Protons may leak through membranes and not travel through ATP synthase enzyme
similarities between structure of NAD and ATP
- both have ribose sugar
- both have adenine base
- both have phosphate group
differences between structure of NAD and ATP
- NAD has one phosphate, ATP has 3
- NAD has 2 nitrogenous bases, ATP only has one
- NAD is di-nucleotide, ATP is nucleotide
symbol equation for anaerobic respiration in yeast
glucose -> ethanol + carbon dioxide
symbol equation for anaerobic respiration in humans
glucose -> lactic acid
After glycolysis has occurred, there is no more NAD left to be reduced… explain how we reoxidise NADH with oxygen again?
activate the lactate fermentation pathway in animals and ethanol fermentation pathway in fungi.
how does lactate fermentation work so that NAD can be reused in glycolysis again?
pyruvate binds with NADH which becomes oxidised (loses H ion). This is transferred to pyruvate which becomes lactate catalysed by lactate dehydrogenase enzyme. The products are lactate and NAD.
how does ethanol fermentation work so that NAD can be reused in glycolysis again?
stage 1: pyruvate broken down using pyruvate decarboxylase into ethanal and carbon dioxide.
stage 2: ethanal binds with NADH and is catalysed by ethanol dehydrogenase to form ethanol and NAD.
why do we continue to breath heavily after exercise?
this provides extra oxygen to liver cells to enable them to metabolise lactate.
why might athletes experience fatigue?
reduction in pH caused by presence of lactate - this will reduce enzyme activity in muscles
why do brewers place their yeast in aerobic conditions first?
to allow them to respire to grow and produce really fast.
what is the hydrogen acceptor in lactate fermentation
pyruvate
what is the hydrogen acceptor in ethanol fermentation
ethanal
which fermentation pathway produces CO2?
ethanol fermentation
enzyme used in lactate fermentation
lactate dehydrogenase
enzyme used in ethanol fermentation
pyruvate decarboxylase and ethanol dehydrogenase
where does oxidative phosphorylation occur?
inner membrane
what are the products of link reaction?
2 x CO2
2 x acetyl coA
2x NADH
what is oxidative phosphorylation
formation of ATP in presence of oxygen
what do coenzymes in inner membrane do?
pumps H ions into inner membrane and uses energy released to cause proton-electrochemical gradient
how is water made at the end of an electron transport chain?
- electrons are passed from the last electron carrier in the chain and donated to oxygen which acts as final electron accepter.
- H ions also join so oxygen is reduced to water.
state the equation for the making of water in ETC
2h+ + 4e- + O2 —–> 2H20
why do lipids have higher energy content than that of carbs and proteins?
they have higher proportion of h atoms compared with C and O. These H ions are used in oxidative phosphorylation of so they produce lots of ATP.
why are lipids useful in glycolysis?
when lipids are broken down into fatty acids these are concerted into TP which is used in glycolysis to make pyruvate.
