3.1/3 respiration and ATP Flashcards
What is ATP and what is it used for?
A nucleotide that is the energy source in all cells. Used in:
-Active transport
-Cell division
-Nerve transmission
What does universal energy currency mean?
It is used for all reactions in all cells in all organisms
What is in ATP?
1 ribose
1 adenine
3 phosphate groups
Describe ADP to ATP
-Endergonic (takes in energy)
-Condensation
-Catalysed by ATPsynthase
Describe ATP to ADP
-Exergonic (releases energy)
-Hydrolysis
-Catalysed by ATPase
What are the positives of ATP?
-Only 1 enzyme for breakdown
-Release energy quickly and in small amounts
-Cell can synthesise its own ATP
-If all energy was released, heat would damage cells
What are the products of glycolysis? (per glucose)
-2 ATP
-2 NADH
-2 Pyruvate
How is ATP produced in anaerobic conditions?
Glycolysis occurs, and pyruvate is converted to lactate, oxidising NADH to NAD
What are the products of link reaction? (per glucose)
- 0 ATP
-2 NADH
-2 CoA
-2 CO2
What enzymes are used in link reaction?
-Decarboxylase
-Dehydrogenase
What are the products of the Krebs cycle? (per glucose)
-2 ATP
- 4 CO2
-6 NADH
-2 FADH2
How much ATP can 1 molecule of NADH produce?
3 ATP
How much ATP can 1 molecule of FADH2 produce?
2 ATP
What are the causes of not reaching maximum yield of ATP?
-Leaky membranes
-Loss of energy as heat
-ATP used for active transport of pyruvate
-Not optimum pH/temp for enzymes
Explain why leaky membranes can cause inefficiency
H ions leak through inner mitochondrial membrane instead of going through ATPsynthase and producing ATP
What is the role of electrons in chemiosmosis?
They undergo redox reactions whilst being passed through electron carriers, powering H pumps
How does cyanide affect chemiosmosis?
Stops flow of electron, preventing it from being accepted by Oxygen, So FADH2 and NADH can’t be oxidised, ATP synthesis will stop
What is substrate level phosphorylation?
Enzymes remove high energy phosphate from substrate and directly transfers it to ADP
What is oxidative phosphorylation?
Electrons moving through ETC and the production of proton-motive force that drives ATP production
What happens to lactate?
-Most is produced in skeletal muscle cells
-Lactate diffuses into blood and taken to hepatocytes (liver)
-Some converted to pyruvate and enters aerobic respiration when Oxygen is available
-Some converted to glycogen and stored
What is the plant equivalent of lactate?
Ethanol
What is anaerobic respiration in plants called?
Fermentation
Explain the respiration of lipids?
-Glycerol enters as Triose Phosphate
-Yields 39 kj/g
-Exact number depends on length of hydrocarbon chain of fatty acid fragments
-When chain is broken down to Acetyl CoA, H is released and picked up by NAD and fed into ETC
How is protein respired?
-yield is 17kj/g
-NH2 group removed in liver (deamination)
-Keto-acids enter krebs cycle or glycolysis to form pyruvate
What is the equation for the respiratory quotient?
Volume of CO2 out/ Volume of O2 in
What is the order for which the food groups would be respired?
1) Carbohydrates
2) Lipids
3) Protein
