Unit 5B: Respiration Flashcards
Structure of ATP
Adenine, ribose, 3 phosphates
Features of ATP
- immediate energy source
- cannot be stored so constantly produced
Equation of aerobic respiration
C6H12O6 + 6O2»_space;> 6CO2 + 6H2O
Use of aerobic respiration
- transporting substances across membranes
- anabolic reactions
- movement
- maintaining body temperature
Examples of use of aerobic respiration
- sodium potassium pump
- expcytosis
- synthesis of DNA
- synthesis of proteins
- cellular movement of chromosomes
- mechanical contraction
Four stages of aerobic respiration
1) glycolysis
2) link reaction
3) krebs cycle
4) oxidative phosphorylation
What are coenzymes
- molecules that aid enzymes by transferring a chemical group between molecules
Process of glycolysis
1) phosphorylation - 2 phosphate molecules are added to glucose to make it more reactive
2) splitting of glucose - for each triose phosphate, NAD is reduced, 4 ATP is produced, 2 pyruvate produced
3) production of ATP - 4Pi + 4ADP»_space;> 4ATP
Products of glycolysis
- 2 NADH is used for oxidative phase
- 2 pyruvate is used for link reaction
- 2 ATP is used for energy
Process of link reaction
- pyruvate loses an electron forming CO2
- 2C complund then forms acetyl group where it loses H+ atoms, NAD is reduced
- acetyl compound transferred to coenzyme A to form acetyl CoA
- glycolysis splits glucose into 2 pyruvate molecules, link reaction occurs twice per glucose
Products of link reaction
2 acetyl CoA - krebs cycle
2 CO2 - waste product
2 NADH - oxidative phosphorylation
Main steps of the krebs cycle
1) formation of 6C compound
2) formation of 5C
3) regeneration of oxaloacetate
What is the formation of 6C
- coenzyme A releases acetate group
- coA goes back into link reaction
- acetate (2C) is joined by oxaloacetate 4C
- makes citrate 6C
- citrate is converted back to oxaloacetate in series of redox reaction
What is the formation of 5C
- carboxyl group removed from citrate, producing CO2
-hydrogen reduces NAD - 5C (ketoglutarate)
What is the regeneration of oxaloacetate
- decarboxylation produces CO2
- dehydrogenation
- FADH and NADH
- 3NAD + 1FAD -> 3NADH + H+ + FADH2
- phosphorylation, transferred from an intermediate compound to ADP
- citrate converted to oxaloacetate
Products of krebs cycle
- CoA goes to link reaction
- oxaloacetate goes to regenerating for next krebs
- CO2 is a waste product
- ATP is used for energy
- NADH goes to oxidative phosphorylation
- FADH goes to oxidative phosphorylation
Process of oxidative phosphorylation
1) hydrogen atoms released from reduced NAD and reduced FAD, into e- and H+
2) electrons move down ETC, losing energy as they move down
3) energy is used to pump protons from the matrix across the inner mitochondrial membrane into inner membrane space
4) conc of protons is mow higher in the inner membrane space than the matrix, forming an electrochemical gradient
5) protons move down the gradient via ATP synthase, synthesising production of ATP by chemiosmosis
6) protons and electrons combine with oxygen to form water
Anaerobic respiration process
- pyruvate is converted into ethanol (alcoholic fermentation) in plants and yeast
- pyruvate is converted into lactate (lactic acid) in lactate fermentation in animal cells and some bacteria
- get regeneration of NAD (as it is oxidised)
- meaning that glycolysis can continue when there isnt much oxygen
