5.1 Flashcards
cellular respiration
process by which energy from food is transferred to ATP
respiratory substrate
food/substance broken down in respiration
aerobic respiration
form of cellular respiration that happens with oxygen
glucose + oxygen –> carbon dioxide + water + ATP
aerobic respiration steps
glycolysis
link reaction
Krebbs cycle
electron transport chain
glycolysis
cytoplasm
phosphorylation occurs
6c glucose is broke down by atp to form glucose 6 phosphate
phosphorylation occurs again
phosphorylated sugar splits to give 2 molecules of 3c sugar
atp, h+ and nadh produced
pyruvate is the product
link reaction
links glycolysis and Krebbs cycle as glucose is too large to enter the mitochondria
pyruvate contains chemical energy
when o2 is available pyruvate will enter the mitochondrial matrix by active transport and matrix joins in link reaction
-pyruvate is oxidised by enzymes to produce acetate and co2 requiring the reduction of nad to nadh
-combination with coenzyme A to form acetyl coenzyme A 2c
-co2 reduced and nadh is oxidised
acetyl coenzyme a can now enter krebbs cycle
Krebb cycle
2c acetyl coenA combines with the 4c compound to form 6c citrate (oxidised)
citrate looses co2 forming citric acid
5c citric acid now goes through cyxlical reactions where it is broken down to the original 4c compound
two further co2 molecules are removed and used as waste
4c then combines with more 2c acecoA and cycle begins again
nadh and fadh enter the etc
ezymes formed in ribosome
products of Krebbs cycle
3 molecules of reduced nadh
1 redfuced fad
1 atp
electron transport chain
occurs in cristae
oxidative phosphorylation reaction
nadh (hydrogen acceptor) transfer H+ ion from coenzyme to coenzyme along an electron transport chain by a series of redox reactions
h+ passed into intermembrane space
h+ flow back through stalked particles by chemiosmosis
energy is used to synthesis atp from adp and pi by a condensation reaction
oxygen is the the terminal acceptor of electrons
water is produced and chain ends
alcholic fermentation
Yeast and other fungal microorganisms
in the first step of the pathway pyruvate is decarboxylated to ethanal, producing CO2
reduced NAD transfers its hydrogens to ethanal reducing it to ethanol
by the enzyme alcohol dehydrogenase
Ethanal is the hydrogen acceptor
Ethanol cannot be further metabolised; it is a waste product
lactate fermentation
Bacteria and mammalian muscle cells
In this pathway reduced NAD transfers its hydrogens to pyruvate to form lactate
Pyruvate is reduced to lactate by enzyme lactate dehydrogenase
Pyruvate is the hydrogen acceptor
The final product lactate can be further metabolised
anaerobic respiration
There is no final acceptor of electrons from the electron transport chain
The electron transport chain stops functioning
No more ATP is produced via oxidative phosphorylation
Reduced NAD and FAD aren’t oxidised by an electron carrier
No oxidised NAD and FAD are available for dehydrogenation in the Krebs cycle
The Krebs cycle stops
glycolysis occurs
some reduced nad is used to reduce pyruvate to lactic acid 3c that disassociates to form lactate and hydrogen ions
only two molecules of atp is formed per glucose
atp is formed directly in glycolysis
why can lipids only be respired in aerobic conditions
in anearobic pyruvate used to reoxidise NADH so no krebb cycle
no oxygen as terminal electron acceptor
reduced NAD cannot be reoxidised
so no coenzyme to bind to H+
respiration of lipids compared to carbs
more atp
-high proportion of hydrogen
-more reduced coenzyme
-more H+ ions for oxidative phosphorylation
chromatography method
add pigment to start
dry and repeat
place paper in solvent
wait until reach near top
