Unit 5B: Respiration

Question 1

Structure of ATP

Answer 1

Adenine, ribose, 3 phosphates

Question 2

Features of ATP

Answer 2

• immediate energy source
• cannot be stored so constantly produced

Question 3

Equation of aerobic respiration

Answer 3

C6H12O6 + 6O2&raquo_space;> 6CO2 + 6H2O

Question 4

Use of aerobic respiration

Answer 4

• transporting substances across membranes
• anabolic reactions
• movement
• maintaining body temperature

Question 5

Examples of use of aerobic respiration

Answer 5

• sodium potassium pump
• expcytosis
• synthesis of DNA
• synthesis of proteins
• cellular movement of chromosomes
• mechanical contraction

Question 6

Four stages of aerobic respiration

Answer 6

1) glycolysis
2) link reaction
3) krebs cycle
4) oxidative phosphorylation

Question 7

What are coenzymes

Answer 7

• molecules that aid enzymes by transferring a chemical group between molecules

Question 8

Process of glycolysis

Answer 8

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&raquo_space;> 4ATP

Question 9

Products of glycolysis

Answer 9

• 2 NADH is used for oxidative phase
• 2 pyruvate is used for link reaction
• 2 ATP is used for energy

Question 10

Process of link reaction

Answer 10

• 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

Question 11

Products of link reaction

Answer 11

2 acetyl CoA - krebs cycle
2 CO2 - waste product
2 NADH - oxidative phosphorylation

Question 12

Main steps of the krebs cycle

Answer 12

1) formation of 6C compound
2) formation of 5C
3) regeneration of oxaloacetate

Question 13

What is the formation of 6C

Answer 13

• 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

Question 14

What is the formation of 5C

Answer 14

• carboxyl group removed from citrate, producing CO2
  -hydrogen reduces NAD
• 5C (ketoglutarate)

Question 15

What is the regeneration of oxaloacetate

Answer 15

• decarboxylation produces CO2
• dehydrogenation
• FADH and NADH
• 3NAD + 1FAD -> 3NADH + H+ + FADH2
• phosphorylation, transferred from an intermediate compound to ADP
• citrate converted to oxaloacetate

Question 16

Products of krebs cycle

Answer 16

• 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

Question 17

Process of oxidative phosphorylation

Answer 17

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

Question 18

Anaerobic respiration process

Answer 18

• 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