Respiration Flashcards
Aerobic and anaerobic respiration?
Aerobic:
O2 + More ATP produced + mitochondria
Anaerobic
No O2 + Less ATP + in the cytoplasm + only glycolysis + produces lactic acid
Aerobic Respiration 4 stages
Glycolysis = cytoplasm
Link Reaction = Inner membrane of mitochondria
Krebs cycle = Matrix of mitochondria
Electron Transport Chain = In Cristae on enzymes
Glycolysis
See Book diagram
Converts large glucose molecules to smaller ones which can be converted into pyruvate and transported into mitochondria
2ATP are needed to phosphorylate glucose
Phosphorylated glucose (hexose bisphosphate) immediately splits into 2 3C Tripose phosphates
TP is oxidised to pyruvate by NAD forming NADH. A total of 4 ADP formed through substrate level phosphorylation
End products of Glycolysis?
2ATP (net gain)
2 NADH
2 pyruvate
Link reaction
See book diagram
Pyruvate crosses the mitochondrial membrane into the matrix
Pyruvate oxidised by NAD forming NADH
Pyruvate is decarboxylated forming CO2
Resulting 2 carbon molecule is picked up by co-enzyme A to from Acetyl CoA
Krebs Cycle
See book diagram
Occurs in matrix
Acetyl CoA enters krebs cycle and combines with axalocetane
Forms Citrate (6C)
Citrate undergoes 2 decarboxylation reactions removing 2 CO2s + a series of oxidation reactions
3NAD –> 3 reduced NAD (NADH +H+)
FAD –> reduced FAD (FADH2)
After first decarboxylation a 5C molecule is made
ATP is produced as a result of substrate-level phosphorylation
Results of this series of reactions is the production of 4C oxaloacetate - cycle goes round again
Products of Krebs cycle
4x CO2 by decarboxylation
6x NADH by redox
2x FADH2 by redox
2x ATP by substrate level phosphorylation
Electron transport chain
Cristae
NADH+, H+ and FADH2 are dehydrogenated releasing H+ and e-
e-s pass down the complex of proteins (ETC) releasing energy as they do
Used to pump H+ against their concentration gradient across the inner mitochondrial membrane
H+ (proton) gradient created
H+ move through ATP synthase down the concentration gradient forming ATP (ADP + Pi = ATP)
O2 acts as a terminal electron acceptor binding with H+ and e- to from H20
Anaerobic respiration in animal
Occurs in cytoplasm in absence of O2
2ATP are needed to phosphorylate glucose
Phosphorylated glucose immediately splits into 2 3C Tripose phosphates
TP is oxidised to pyruvate by NAD forming NADH and 2 ATP forming
Net gain of 2 ATP
Pyruvate further reduced by NADH to NAD forming Lactate
Anaerobic respiration in yeast
Occurs in cytoplasm in absence of O2 2ATP are needed to phosphorylate glucose Phosphorylated glucose immediately splits into 2 3C Tripose phosphates TP is oxidised to pyruvate by NAD forming NADH and 2 ATP forming Pyruvate is decarboxylated - loss of CO2 Ethanal formed NADH to NAD Ethanol formed
Anaerobic respiration regeneration
Production of lactate or ethanol regenerates oxidised NAD
Glycolysis can continue when there isn’t much oxygen so a small amount of ATP can still be produced
How many ATP can be made from one glucose molecule?
32
How can ATP production be affected?
Mitochondrial diseases:
Affect proteins involved in oxidative phosphorylation or the krebs cycle function, reducing ATP production
May cause anaerobic respiration to increase - ATP shortage
May cause lots of lactate to form - muscle fatigue or weakness
Other upstarts in aerobic respiration?
Fatty acids from lipids
Amino acids
Investigating Factors affecting respiration in single-celled organisms - aerobic respiration?
Decide on different temperatures for dependent variable
Known volume and concentration of substrate solution in a test tube + buffer solution to keep pH constant
Place in water bath set at one of the temperatures
Leave for 10 mins for substrate to stabilise
Add known mass of dried yeast and stir for 2 mins
When dissolved add a bung on test tube attached to a gas syringe which is set to zero
Measure CO2 formed
At regular intervals measure CO2 released
Control with no yeast
Repeat at different temperatures
Find mean rate of CO2 production
