5.7 RESPIRATION

Question 1

Define respiration

Answer 1

• The release of energy stored in organic molecules (glucose)

Question 2

State the full path of the energy released during respiration

Answer 2

• Uses the energy to form ATP by joining a molecule and ADP and inorgnaic phosphate (Pi)
• When energy is required, ATP is hydrolysed back into ADP and Pi to release energy for processes

Question 3

State five biological processes that rely on energy

Answer 3

1) Active transport
2) DNA replication
3) Cell division
4) Endocytosis/exocytosis
5) Movement (flagellum/motor proteins)

Question 4

Which groups of organic moelucules store energy

Answer 4

• Proteins/Lipids/Carbohydrates

Question 5

Draw and label a mitochondria

Answer 5

Question 6

Define the mitochondrial envelope

Answer 6

• The inner and outer membrane of a mitochondria

Question 7

Define the outer membrane

Answer 7

• Smooth phospholipid composition (similar to cell surface membrane)
• Allows entry of pyruvate

Question 8

Define inner membrane

Answer 8

• Lipid bilayer thats folded into cristae to enhance surface area
• Less permeable than outer membrane
• Site of oxidative phosphorilation

Question 9

Define matrix

Answer 9

• Fluid-filled inner part, contains mitochondrial ribosomes and looped mitochondrial DNA

Question 10

Define inter-membrane space

Answer 10

• Space between inner and outer membrane

Question 11

Define and describe the role of the matrix

Answer 11

• Fluid-filled inner part
• Where kreb cycle and link reaction occur
• Contains enzymes that catalyse the stages of the reaction
• Contain coenzymes NAD and FAD
• Contain looped mitochondrial DNA to code for mictochondrial enzymes/proteins
• Contain mitochondrial ribosomes to assemble these proteins

Question 12

Describe the roles of inner and outer membrane

Answer 12

• Outer membrane is highly permeable to allow movement of pyruvate into the mitochondria
• Inner membrane is less permeable and the site of oxidative phosphorilation
• Mitochondrial membrane responsible for formation/maintanance of H+ proton gradient across inner membrane due to the proton build up in the intermembrane space
• Inner membrane contains electron carriers/ATP synthase/proton pumps

Question 13

Draw the overall pathway of respiration

Question 14

State the four steps of aerobic respiration

Answer 14

1) Glycolysis
2) Links reaction
3) Kreb cycle
4) Oxidative phosphorilation

Question 15

State the two steps for anaerobic respiration

Answer 15

1) Glycolysis
2) Lactate fermentation or ethanol fermentation

Question 16

State where glycolysis occurs

Answer 16

• The cell cytoplasm (not mitochondria)

Question 17

Outline the three stages of glycolysis

Answer 17

1) Phosphorylating glucose into hexose biphosphate using ATP
2) Splitting the hexose biphosphate into two triose phosphate molecules
3) Oxidation of triose phosphate to pyruvate

Question 18

Define glycolysis

Answer 18

• Converting glucose into pyruvate

Question 19

State the products of glycolysis

Answer 19

1) Two molecules of ATP
2) Two molecules of reduced NAD
3) Two molecules of pyruvate

Question 20

Describe phosphorilation during glycolysis

Answer 20

• One molecule of ATP is hydrolysed and the released phosphate group is added to glucose to make hexose biphosphate