3.1/3 ATP and respiration Flashcards
what is ATP
a phosphorylated nucleotide
what features does mitochondria have
inter membrane space
outer mitochondrial membrane
inner mitochondrial membrane
matrix
cristae
ring of DNA
70s ribosome
what is the purpose of glycoloysis
to break down glucose, as it won’t go into mitochondria.
what does glycolysis happen
to break glucose into smaller molecules to carry on the rest of respiration to make ATP
what does phosphorylated mean
adding a phosphate
what does glycolysis start with
glucose
what happens to glucose in glycolysis
glucose is phophorylated, an ATP is added and hydrolysed
glucose goes into hexose phosphate
what does hexose phosphate go to
an ATP is added and goes to hexose diphosphate
what happens to hexose diphosphate
it is unstable so dissociates into 2x triose phosphate
what is NAD
a co-enzyme used with dehydrogenase enzymes
what happens to 2x triose phosphate
oxidation/dehydrogenation reaction
triose phosphate is oxidised by NAD
NAD goes to NADreduced
what happens between 2x triose phosphate and 2x glycerate 3 phosphate
2 ATP are made by substrate level phosphorylation
what happens to glycerate 3 phosphate
2x pyruvate
and another 2 ATP are made by substrate level phosphorylation
how many ATP are used per glucose
(glycolysis)
2
how many ATP are made per glucose
(glycolysis)
4
net ATP per glucose
(glycolysis)
2
NAD reduced
per glucose
(glycolysis)
2
FAD reduced
per glucose
(glycolysis)
0
CO2 produced
(glycolysis)
0
how many times does the link reaction happen per glucose
twice
where does glycolysis happen
in the cytoplasm
where does the link reaction happen
in the mitochondrial matrix
what happens to pyruvate in the link reaction
it is oxidised
CO2 is removed and co-enzyme A is added
NAD goes to NAD reduced
how many carbons in the following:
glucose
hexose phosphate
hexose diphosphate
2x triose phosphate
2x glycerine 3 phosphate
2x pyruvate
6
6
6
2 x 3c
2x3c
2x 3c
how many carbons in the following:
pyruvate
acetyl co-enzyme A
3c
2c
per glucose
link reaction
ATP used
ATP made
Net ATP
NAD reduced
CO2 produced
0
0
0
2
0
2
purpose of the Krebs cycle
to reduce NAD
where does the Krebs cycle happen
mitochondrial matrix
what goes into the Krebs cycle and what happens
acetyl CoA goes into the Krebs cycle and joins to the 4c to make a 6c. the CoA is regenerated
6c to 5c
decarboxylation reaction (CO2 removed)
6c is oxidised, oxidation reaction NAD to NAD reduced
5c to 4c
decarboxylation reaction (CO2 out)
5c is oxidised
NAD to NAD reduced
4c (1) to 4c (2)
oxidation reaction
FAD to FAD reduced
4c (2) to 4c (3)
oxidation reaction NAD to NAD reduced
where does the electrons transport chain occur
on the inner membrane of the mitochondria
what increases the surface area in the inner membranes
infoldings called Cristae
what are in the ETC
electron carriers and proton pumps within the inner membrane and ATP synthetase enzyme
what happens in the ETC
electrons pass through a series of electron carriers in the inner mitochondrial membrane by REDOX reactions which produces energy
explain oxidative phosphorylation
reduced NAD and FAD are reoxidesided. the NAD and FAD return to glycolysis, links and Krebs
they donate 2H and splits into 2 electrons and 2 protons
in the ETC what happens to the and hydrogen ions eventually
what are electrons mopped up by?
oxygen-
called the final electron acceptor
what is the energy from the ETC used for
used to actively transport H+ from the matrix to the inter-membrane space. this creates an electrochemical gradient
what can an electrochemical gradient also be known as
pH gradient/ proton gradient
explain what happens to the H+ ions after the electrochemical gradient
the H+ pass through the protein channel to return into the matrix by diffusion (down the concentration gradient) this is called chemiosmosis
how is ATP produced
as the H+ pass through the protein channel, they rotate the enzyme ATP synthetase (attached to a stalked particle) this catalysed ADP+Pi goes to ATP
H+ mopped up by o2
fully explain oxidative phosphorylation
- reduced NAD becomes oxidised, splits into a proton and electron
- electrons fuel the protons pumps
- energy allows the proteins to pump protons from matrix to inter-membrane space (electrochemical gradient)
- reduced FAD oxidised splitting into a proton and electron
- protons then diffuse back across the inner membrane from the inter-membrane space to the matrix (down concentration gradient) via ATP synthetase
- as the reduced NAD fuels three pumps, 3 molecules of ATP are generated
- reduced FAD fuels 2 pumps, 2 ATP made
- oxygen= final electron acceptor and combines with the electrons and protons to from water. helps maintain concentration gradient
what’s the importance of oxygen as the final electron acceptor
helps to maintain the concentration gradient
how many ATP’s are made in glycolysis by:
- substrate level phosphorylation
-reduced NAD
-reduced FAD
2
6 (2x3)
0
how many ATP’s are made in the link reaction
-substrate level phosphorylation
- reduced NAD
-reduced FAD
-0
-6 (2x3)
-0
how many ATP are made in Krebs
-sub-level phosphorylation
-reduced NAD
- reduced FAD
- 2
- 18 (6x3)
- 4
how many ATP’s are made in total
38 altogether
function of the loop of DNA found within the mitochondrion
- so they can self replicate
- so that it can code for making enzymes
where does anaerobic respiration happen
cytoplasm
explain anaerobic respiration in animals
glycolysis happens
then
2x pyruvate undergoes oxidation reaction
2x reduced NAD to 2NAD
into lactate (lactic acid)
explain anaerobic respiration in yeast and plants
glycolysis
2x pyruvate has a decarboxylation reaction, CO2 leaves into 2 ethanol
reduced NAD to NAD
into 2 ethanol
what needs to be done before respiration can happen with non-carbohydrates
molecules must be hydrolysed by the cell
lipids are broken down to fatty acids and glycerol
proteins are broken down into amino acids
when are other molecules used instead of glucose in respiration
respiration of lipids is carried out when there’s no glucose
protein is only used in cases of extreme shortage of other substrates
explain respiration of lipids
the glycerol part of the lipid has 3c. it’s phosphorylated using ATP and enter the chain as a triose phosphate molecule. fatty acid broken into 2c acetyl fragments can go in and be picked up by Coenzyme A and go on to enter the Krebs cycle
how many ATP molecules are produced from the single glycerol molecule
and each acetyl fragments
18
12
why is fat a useful energy storage molecule in animals and plants
level potential ATP production is much higher with lipids for a molecule of glucose
what’s a possible issue with the respiration of lipids
huge oxygen demand it requires. the large numbers of turns of grebes for each fatty acid produce an even larger number of reduced hydrogen acceptors which in turn require an equally large number of oxygen molecules to re-oxidise them. (difficult)
explain respiration of proteins
amino acid enters at various points within the Krebs cycle
problems of respiring amino acids
we need the amino acids to make our own polypeptide, protein, hormones, muscles etc. so we don’t want to be wasting them on respiration
explain why ATP is described as the universal energy currency
it is used in all cells in all metabolic reactions
advantages of ATP for its function as a source of energy
- only needs one enzyme to release energy
- released in small amounts (30.6) efficient, not wasted
-it’s soluble can move around the cell
explain why the two hydrogen acceptors NAD and FAD lead to the production of different numbers of ATP molecules
because NAD can fuel three proton pumps, FAD can only fuel two proton pumps
ETC for NAD has more electron carriers than FAD
