TOPIC 7 RESPIRATION 7.1 - 7.6 Flashcards
What are the Requirements of glycolysis
Not oxygen
First step of aerobic and anaerobic respiration
Steps of glycolysis - phosphorylation of glucose
two molecules of ATP are required to provide two phosphate needed for phosphorylation of glucose
Steps of glycolysis - phosphorylation of glucose
What does it produces
Two molecules of triose phosphates
Steps of glycolysis - oxidation of triose phosphate
After triose phosphate loses hydrogen it forms two molecules of pyruvate
The hydrogen ion are collected by NAD which reduces coenzyme
Steps of glycolysis - oxidation of triose phosphate what does it produces
Two reduced NAD
*even tho total of 4 ATP Were produced
Where does glycolysis
Cytoplasm
Where does link reaction occur
Mitochondrial matrix
Link reaction process
The pyruvate(3C) made in glycolysis is oxidised to acetate (2C)
—> decarboxylase remove carbon dioxide (1C)
NAD picks up hydrogen and becomes NADH —> dehydrogenase
Acetate(2C) the combines with coenzyme A in to produce acetylcoenzyme A (2C)
Products of link reaction occurs twice for every glucose molecules
2x acetyl CoA
2x CO2 released
2 NADH
Kreb cycle process
1) acetyl coenzyme A (product from link reaction) is combined with 4C molecules
2) 6C molecule undergoes oxidation as hydrogen atoms reduce 3x NAD and 1x FAD
3) two molecules of CO2 are released
4) phosphorylation of ADP produces ATP
Kreb cycle input
2x acetyl coenzyme A
6x NAD
2x FAD
2x ADP
Kreb cycle output
4x CO2
6X NADH
2X FADH2
2x ATP
Electron transport chain process
1) hydrogen atoms are donated by NADH and FADH2 from kreb
—> hydrogen atoms splits protons and electrons
2) high energy electron enters the ETC and release energy as they move through ETC
3)the energy released transport protons across the inner mitochondrial membrane from the matrix into the inter membrane space
4) a concentration gradient of proton is established between the inter membrane space and the matrix
5) chemiosmosis occurs - diffusion/net movement of protons down the electrochemical gradient through ATP synthase the proton return to the matrix via facilitated diffusion through the channel enzyme ATP synthase
6)movement of protons down their concentration gradient provide energy for for ATP synthasis
—> to bring ADP + Pi = ATP
7) oxygen acts as the ‘final electron acceptor’ and combines with proton and electron at the end of ETC to form H2O
Describe the role of the H+ gradient in making ATP
- H+ are more concentrated intermembranal space compared to the matrix into the intermembranal space by protein in the inner membrane of mitochondria
- H+ travel down their electrochemical gradient via the ATP synthase channel
-movement of H+ provides energy for the phosphorylation of ADP to form ATP
Electron transport chain input
10x NADH
2X FADH2
6X O2
~ 36X ADP
Electron transport chain output
10x NAD
2X FAD
6X H2O
~ 36X ATP
Process of glycolysis
1) phosphorylation
- glucose is phosphorylation to glucose phosphate using ATP (which gets converted into ADP)
- glucose phosphate is then phosphorylation to hexose biphosphate using another ATP molecules
-the or biphosphate is the hydrolysis into 2 molecules of triose phosphate
OXIDATION
-2 triose phosphate are oxidised forming 2 molecules of pyruvate
-NAD collects 2H+ ions forming 2 NADH
- 4 ATP are produced, but 2 were used up in phosphorylation so there is a net gain 2 ATP in glycolysis
Lactate fermentation animals formula
Pyruvate —> lactate —> glucose
Anaerobic respiration in mammals
Glucose —> lactic acid
C6H12O6 —> 2C3H6O3
Anaerobic respiration in plants and fungi
C6H12O6 —> 2C2H5OH + 2CO2
Glucose —> ethanol + carbon dioxide
Anaerobic respiration consequences
Little or no oxygen
There is no final acceptor of electron from the ETC
Electron transport chain stops functioning
No more ATP is produced via oxidative phosphorylation
NADH and FAH2 aren’t oxidised by an electron carrier
No oxidised NAD and FAD are available for dehydrogenation in the Kreb cycle
The Kreb cycle stops
Link reaction stops
Advantage of lactate
Can survive temporarily shoRage of oxygen
Used in strenuous exercise when the oxygen supply doesn’t match the demand
How does pyruvate form lactate
Each pyruvate molecules takes two hydrogen from NADH oxidising to NAD to form lactate
Pyruvate is reduced to lactate by enzyme lactate dehydrogenase
Pyruvate + NADH = lactate + NAD
Production of lactate
Once oxygen is available again
The lactate can be oxidised back into pyruvate
This can be further oxidised to release energy or converted into glycogen
How does lactate effect in muscle
Lactate caused cramp and muscle fatigue if left in the muscle tissue
Lactate is an acid, so changes the pH
pH changes effect the enzyme
Muscle has some tolerance to lactate but it still need to be removed by the blood taken to the liver and converted into glycogen
Lactate is carried to the liver in blood
Converted back to pyruvate and respires in the liver cells
Oxygen is needed to oxidise the pyruvate made from the accumulated lactate
.
How to make ethanol
Each pyruvate molecules lose a molecule of carbon dioxide (decarboxylated) to ethanal by pyruvate decarboxylase
NADH transfer H to ethanal to form ethanol alcohol dehydrogenase
Processing lactate
After lactate is produced:
-oxidised back to pyruvate which is then channelled into the Kreb cycle for ATP production
-can be converted into glucose by the liver cell for use during respiration or for storage
Oxidation of lactate back to pyruvate needs oxygen
-this extra oxygen is referred as oxygen debt
—> breathe deeper and faster after exercise
