5.2.2 - Respiration

Question 1

Respiration

Answer 1

Process by which energy stored in complex organic molecules is released and immediately transferred to ATP
Energy is released through hydrolysis (making new bonds)

Question 2

Why do animals need energy

Answer 2

Active transport 
Endo/exocytosis
Synthesis of protein
DNA replication 
Cell division 
Movement 
Activation of a chemical (phosphorylation)

Question 3

Catabolic

Answer 3

Releasing energy

Question 4

Anabolic

Answer 4

Energy consuming

Question 5

ATP

Answer 5

Intermediary between catabolic and anabolic reactions
Relatively stable, only broken down by hydrolysis by enzyme catalysis (energy released can be controlled)
Easily moved around a cell when in solution

Question 6

Hydrolysis of ATP

Answer 6

Catalysed by ATPase
ATP is hydrolysed to produce ADP then again to produce AMP
ATP –> ADP (-30.5), ADP –> AMP (-30.5), AMP —> A (-13.8)

Question 7

Structure of ATP

Answer 7

Ribose attached to adenine (phosphodiester bond)
3 inorganic phosphate groups
Phosphorylated nucleotide

Question 8

Processes in aerobic respiration

Answer 8

Glycolysis
Link reaction
Krebs cycle
Oxidative phosphorylation

Question 9

Glycolysis

Answer 9

Occurs in cytoplasm
Phosphorylation —> hexose biphosphate (2 phosphate groups from 2 ATP)
Hexose biphospahe splits into two
Oxidation (removal of H atoms) - accepted by NAD to make NADH
Breaks down glucose into pyruvate (3C), 2 NADH and 2 ATP

Question 10

Where does glycolysis occurs

Answer 10

Cytoplasm

Question 11

Why are ATP used in the first stage of glycolysis

Answer 11

Provide activation energy

Question 12

Where does oxidative phosphorylation occur

Answer 12

Cristae

Question 13

Role of ATP in the cell

Answer 13

Universal currency of energy
Phosphates can be removed by hydrolysis to release 30 kJ/mol energy
Energy used in metabolic reactions
Energy released in small quantities to prevent cell damage

Question 14

Where does the Kreb’s cycle occur

Answer 14

Matrix of mitochondria

Question 15

Coenzymes in leaf

Answer 15

NAD and FAD can be reduced to NADH and FADH2 and act as hydrogen carriers
Coenzyme A carries acetate to Kreb’s cycle

Question 16

Link reaction

Answer 16

Pyruvate is decarboxylated to acetate (+ CO2)
Combines w/ CoA to make acetyl coenzyme A
Happens twice for glycolysis
Produces 2 NADH

Question 17

Kreb’s cycle

Answer 17

CoA is recycled back to link reaction
Acetate combines with oxaloacetate to make citrate
Decarboxylated 2x to give orig. 4C compound, oxaloacetate
Produces 6 NADH, 2 FADH2 , 2 ATP and 4 CO2 (substrate level phosphorylation)

Question 18

Which cofactor is part of the ETC

Answer 18

Fe^2+

Question 19

What’s found in the matrix

Answer 19

Enzymes 
NAD
FAD
Oxaloacetate 
Mitochondrial DNA
Mitochondrial ribosomes

Question 20

Mitochondrial DNA

Answer 20

Codes for mitochondrial enzymes and other proteins

Question 21

Mitochondrial ribosomes

Answer 21

Where proteins are assembled

Question 22

Where can fatty acids be used in respiration

Answer 22

Fatty acids can produce acetate and enter the Kreb’s cycle directly

Question 23

Where can glycerol be used in respiration

Answer 23

Can be converted to purivate and enter the link reaction

Question 24

Where does the link reaction occur

Answer 24

Matrix of mitochondrion

Question 25

Theoretical yield of ATP from 10 NADH

Answer 25

25

Question 26

Total theoretical yield of ATP

Answer 26

25 - NADH 2 - FADH2 3 - Krebs cycle 2 - glycolysis =32

Question 27

Why is the yield of ATP not 100%

Answer 27

ATP has to be used for active transport of pyruvate and NADH

Question 28

RQ

Answer 28

Vol. of CO2/ Vol. of O2 per unit time

Question 29

RQ value for glucose

Answer 29

1

Question 30

RQ value for AA

Answer 30

0.8/0.9

Question 31

RQ value for triglycerides

Answer 31

0.7

Question 32

Investigating respiration rates of yeast

Answer 32

Put a known vol. and conc. of a substrate sol. into a tt Add a known vol. of buffer soln. - keep pH constant Place tt in water bath (25 degrees) Add known mass of dry yeast After yeast has dissolved , place a bung on the tt which is attached to a gas syringe (should be set to 0) Start the stopwatch Record vol. of CO2 produced at regular intervals and calculate rate

Question 33

Using a respirometer to measure O2 consumption

Answer 33

Set up respirometer - one w/ glass beads and the other w/ woodlice of same vol. Add KOH to both - absorbs CO2 produced Use syringe to set fluid in manometer to known level Measure distance travelled by liquid in manometer - gives you vol. of O2 used up (pi r^2 h - need diameter of capillary tube)

Question 34

Why does the liquid move in the manometer

Answer 34

As the woodlice use up the O2, pressure decreases causing coloured liquid in manometer to move towards tt

Question 35

Limitation of using respirometer

Answer 35

Diff to accurately read the meniscus of the fluid in the manometer

Question 36

Substrate level phosphorylation

Answer 36

ATP is formed by the direct transfer of Pi to ADP