3.5.2 Respiration Flashcards
3.5.2 Respiration
what is it meant by the term phosphorlation
the addition of the phosphate group to a molecule
what are the two main types of phosporilation found in respiration
Oxidative phosphorylation – occurs during aerobic respiration where ATP is formed in the electron transport system. “Oxidative” refers to the energy of oxidation/reduction reactions, not oxygen gas.
normally done with the aid of channel or carrier proteins
Substrate level phosphorylation – the formation of ATP by the direct transfer of a phosphate group from a reactive intermediate to ADP
normally done when ATP — ADP
normally does not require Pi as it is found on the substraite
what is respiration
A series of enzyme controlled reactions which produce chemical energy in the form of ATP from organic molecules (mainly glucose)
It can be done aerobically (with oxygen) or anaerobically (without oxygen)
give the general equation for respiration
C6H12O6 + 6O2 —> 6CO2 + 6H2O + (energy)
what is the definition of a co-enzyme
Coenzymes bind with a specific enzyme or substrate, helping to catalyze a reaction. Coenzymes transfer a chemical group (like hydrogen) from one molecule to another.
waht are the three main co-enzymes in respiration and what do they do
NAD (nicotinamide adenine dinucleotide)
transfer hydrogen from one molecule to another (so can oxidise or reduce a molecule)
FAD (flavine adenine dinucleotide)
transfer hydrogen from one molecule to another
Coenzyme A
transfers acetate between molecules
what is it called when you remove a hydorgen
Dehydrogenation: The removal of hydrogen (using dehydrogenase enzymes). Can also therefore be called oxidation.
caould also say deprotonation
what is it called when you remove a carbon to form CO2
Decarboxylation: Removal of carbon (in the form of COOH, using decarboxylase enzymes) to form carbon dioxide
what are the four stages of respiration
glycolysis
the link reaction
krebs cycle
the electron transport chain
where does glycolysis take place , and why
Glycolysis happens in the cytoplasm because the glucose is too large to pass through the outer membrane of the mitochondria
where does the link reaction take place
the matrix of mitochondria
draw out the glycolysis chain reaction and then list the steps
also list the compounds made during these steps
glucose —> glucose phosphate —> hexose biphosphate —> 2x triose phosphate —> 2x pyruvate
1) Glucose is phosphorylated using a phosphate from the hydrolysis of ATP (from a supply in the cytoplasm). giving 1 mol of ATD and one mole of Glucose phosphate
2) phosphorilation from ATP, making hexose biphosphate and ADP
3) lysis of hexose biphosphate making 2 x triose phosphate
4) two triose phosphate is dehydogenated forming two pyruvates
4)B) 2 NAD are then reduced forming reduced NAD , when triose phosphate —-> pyruvates
4)C) 4 ADP and Pi are substraite level phosporliated to produce 4 ATP
what is the net production of ATP in glycolysis
2
you make 4 but loose two to make those two
does glycolysis need oxygen
no it can be done during anerobically or arobically however is a anarobic PROCESS
draw out a mitochondria
https://studymind.co.uk/notes/the-structure-of-mitochondria/
can the link reaction be undergon in arobic respiration and anarobic respiration
no it can only be undergone during aerobic respiration
describe the stages of the link reaction
show the order of compounds made
pyruvate (3c)—> acetate(2c) —–> acetyle CoA (2c)
1) Pyruvate is decarboxylated (carbon removed) in the form of carbon dioxide One carbon is removed
while also reducing 1 NAD to reduced NAD (dehydrogenation)
the end product is acetate (2c)
2) acetate combinds with Coenzyme-A to produce acetyle CoA
remember 2 Acetyle CoA are made per glucose molecules
no ATP is made during this stage
where does the Krebs cycle take place
in the matrix of the mitochondria
what are the stages of the krebs cycle
acetyleCOa drops off CoA and combines with Oxaloacetate to produce citrate (6c)
Citrate –> decarboxilation (produces CO2) —-> NAD to reduced NAD —> decarboxilation (produces CO2) —-> NAD to reduced NAD —-> ADP +Pi goes to ATP —-> FAD to reduced FAD —-> NAD to reduced NAD —–> oxaloacetate
why is reduced FAD produced rather than reduced NAD
The amount of energy released in this part of the Kreb’s cycle is not enough to drive the reduction of NAD to NADH and so FAD is used.
Reduced FAD does not contain as much energy as reduced NAD.
what are the two processes of the electron transport chain
1) Electron Transport Chain
2) Chemiosmosis
where does the electron transport chain take place
in the inner membraine of the mitocondria
what are the steps of the electron transport chain
1) Hydrogen atoms are released from reduced NAD and reduced FAD. They become oxidised to NAD and FAD
The hydrogen atoms split into protons (H+) and electrons (e-)
2)The electrons move along the electron transport chain from one electron protein carrier to another in a series of redox reactions. which is made up of three electron carriers
They lose energy at each carrier
3) The energy that is lost as the electrons moved along the electron transport chain is used by electron carriers .
Electron carriers pump protons from the matrix into the intermembrane space
4) The concentration of protons is now higher in the intermembrane space than in the matrix
This forms an electrochemical gradient (a concentration gradient of ions)
5) Protons can now move down the electrochemical gradient back across the inner membrane and into the matrix
This happens via ATP synthase
This movement drives the synthesis of ATP from ADP and inorganic phosphate (Pi)
6)Protons can now move down the electrochemical gradient back across the inner membrane and into the matrix
This happens via ATP synthase
This movement drives the synthesis of ATP from ADP and inorganic phosphate (Pi)
what is chemiosmosis
Chemiosmosis is the movement of ions across a semipermeable membrane bound structure, down their electrochemical gradient. An important example is the formation of adenosine triphosphate (ATP) by the movement of hydrogen ions (H+) across a membrane during cellular respiration or photosynthesis.
what is oxygen commonly refered to as in the electron transport chain and why
Oxygen is said to be the final electron acceptor
In the matrix, at the end of the transport chain, the protons, electrons and oxygen (from the blood) combine to form water
what happens if you do not have any oxygen in the electron transport cahin
No oxygen? – FAD and NAD cannot be reoxidised and so cannot act as hydrogen carriers. Krebs cycle cannot operate.
what two region does the electron transport chain take place
and also between where
the electron transport chain takes place between the inner mitochondrial membrane
it takes place in two regions called the matrix of the mitocondria and the innermembrane space of the mitocondria
how can fats be used as respiratory substances
Triglyceride is made of glycerol and fatty acids
Glycerol is 3C which is phosphorylated and converted to triose phosphate which enters the glycolysis pathway and subsequently the Krebs cycle. The fatty acids are broken down to 2 C fragments which combine with coenzyme A to form acetyl coenzyme A.
do fats produce a lot of ATP / energy
Fatty acid chains can be very long and so when hydrolysed they form many 2C fragments that can enter where acetyl coenzyme A enters.
The hydrogen atoms can be used to produce ATP during oxidative phosphorylation.
Hence Fats produce a great deal of ATP in respiration.
One gram of fat yields twice the energy of one gram of carbohydrate.
how can proteins be used as respiratory products
In cases of starvation tissue proteins are hydrolysed to amino acids.
Amino acids are deaminated (have the amino group removed) by the liver (urea is formed and eliminated by the kidney)
The remainder of the molecule enter the respiratory pathway at different points depending on how many carbon atoms it contains.
If the amino acid is glycine, it will form a 2C compound and can be used where Acetyl CoA joins the Krebs cycle. There would be Hydrogen to give up in oxidation reactions.
3C compounds formed are converted to pyruvate.
4C & 5C compounds are converted to intermediates in the Kreb cycle
when does anarobic respiration take place
when there is no oxygen
what is the definition of anarobic respiration
Anaerobic respiration is the incomplete intracellular breakdown of glucose or other organic compounds in the absence of oxygen that releases energy.
these questions are on alcoholic fermentation :
what organisums does this take place
This occurs in plants and funghi (yeast)
these questions are on alcoholic fermentation :
when pyruvate goes to ethanal what happens to the pyruvate
it is being decarboxylated
these questions are on alcoholic fermentation :
when ethal goes to ethanol what is happening to ethanl and what co-enzyme is being used
Ethanal is then reduced to form ethanol taking H from reduced NAD .
Oxidised NAD allows glycolysis to continue
what are the featurs of alcoholic fermentation
This occurs in plants and funghi (yeast)
The pyruvate is being decarboxylated to form ethanal
Ethanal is then reduced to form ethanol taking H from reduced NAD .
Oxidised NAD allows glycolysis to continue
Small amounts of ATP can still be produced even without O2
Ethanol becomes toxic to yeast when it accumulates
why is it bad for an acumilation of ethanol
can be toxic to yeast
describe to process of alcohol fermentation
pyruvate goes to ethanal this is done by pyruvate being decarboxilised
ethanl goes to ethanol by being reduced as reduced NAD gives a hydrogen turning it into NAD
what are the featurs of lacate fermentation
and the process
process : pyruvate is reduced to form lactate (lactic acid) in animals by accepting H from reduced NAD
Regenerated NAD means glycolysis can continue
Build up of lactate causes cramp
When O2 is available lactate is broken down in the liver and converted into glycogen.
The oxygen debt is the oxygen needed to break down the lactic acid built up (repaid by deep and rapid breathing).
happens in animals
anarobic respiration plant vs animal
decaboxilation
platns:
yes
animals ;
NO
anarobic respiration plant vs animal:
number of carbons atoms at end point
PLants :
2 carbons
animals :
3 carbons
anarobic respiration plant vs animal:
dehydrogenation
PLANTS :
no
animals :
NO
anarobic respiration plant vs animal
NAD regenerated
both NO
anarobic respiration plant vs animal
is ethanal formed
plants :
yes
animals :
no
anarobic respiration plant vs animal:
is lactic acid made ?
plants :
no
animals :
yes
anarobic respiration plant vs animal
is ethanol made :
plants :
yes
animals :
no
what is the significance of anaerobic respiration :
Ensures ATP production by glycolysis
Removes pyruvate so it does not build up and stop the process
Regenerates oxidised NAD from the reduced NAD produced to prevent it running out in anaerobic conditions (when oxygen is absent)
how much ATP does each reduced NAD produce
2.5 ATP
how much ATP does each reduced FAD produce
1.5
what is the significance of anarobic respiration
esdures ATP production by glycolysis
removes pyruvate so it does not build up and stop the process
regenerates oxidised NAD from the reduced NAD produced to prevent it running out anarobic condition (when oxygen is absent)
