Respiration

Question 1

Name 3 cellular activities that require ATP energy

Answer 1

Muscle contraction
Protein synthesis
Active transport

Question 2

Describe 3 advantages of ATP for its function

Answer 2

It is soluble and easily transported around the cell
An immediate source of energy as only one enzyme is needed to hydrolyse it
Releases energy in useable amounts that are matched closely to the energy required in coupled reaction

Question 3

In aerobic respiration what are the ways in which ATP can be synthesised and describe them

Answer 3

Substrate level phos > where an enzyme transfers a phosphate group from a substrate directly to ADP with no involvement of the ETC

Oxidative Phos where glucose is oxidised in a series of redox reactions that provide the energy to synthesise ATP. Oxygen must be present as the TEA

Question 4

Explain how ADP is involved in making energy available for cells

Answer 4

ADP combined with Pi( an inorganic phosphate) to produce ATP, this reaction is catalysed by the enzyme ATPsynthetase. In order for ATP to release energy the terminal phosphate group is hydrolysed releasing 30.6KJmol-1 of energy. This reaction is catalysed by the enzyme ATPase

Question 5

What is the terminal electron acceptor in aerobic respiration

Answer 5

Oxygen

Question 6

Draw and label a mitochondria

Answer 6

Check

Question 7

What is the origin of the electrons that are passed alone the electron transport chain

Answer 7

Hydrogen atoms, which split to form H+ and E-

Question 8

Why is SLP referred to as the simplest and oldest way to make ATP

Answer 8

Has no involvement of the ETC, no oxygen is needed and needs no pumps or carriers

Question 9

Why does the diameter of the mitochondria not exceed 10 um

Answer 9

Because the diffusion pathway for O2 and CO2 must be as short as possible to be efficient

Question 10

Why does the concentration of oxygen fall sometimes

Answer 10

Because oxygen is the terminal electron acceptor, it combines with H+ and E- to form water so the concentration of pure oxygen falls

Question 11

What is produced in glycolysis

Answer 11

4 ATP and NADH2

Question 12

How is reduced NAD used in aerobic respiration

Answer 12

Supplies high energy electrons to the ETC and protons to the proton pumps in the ETC

Question 13

How is reduced NAD used in anaerobic respiration

Answer 13

Reduces pyruvate to lactic acid

Question 14

Where does the Krebs cycle occur and why here

Answer 14

In the mitochondrial matrix because the enzyme required for the Krebs cycle are located here

Question 15

Explain the process of Krebs cycle

Answer 15

Acetyl CoA enter the cycle and combines with a 4C acid to form a 6C compound
The 6C acid is dehydrogenated, making NADH2 to regenerate the 4C acid
(ATP is also made here by SLP)
The 4C acid can combine with more acetyl coA and the cycle is repeated

Question 16

Why is it important that the 4C acid is regenerated in the Krebs cycle

Answer 16

In order for it to combine with Acetyl coA, to prevent it from accumulating

Question 17

Explain why the overal count of ATP is not always 38

Answer 17

ATP is used to move pyruvate, ADP NADH2and FADH2 across the mitochondrial membrane
The proton gradient may be compromised by proton leakage across the inner mitochondrial membrane rather than passing through ATP synthetase
Molecules may also leak through the membrane preventing ATP from being generated

Question 18

Where is the ETC located

Answer 18

On the cristae of the inner mitochondrial membrane

Question 19

Name the molecules that show net movement into the mitochondrion

Answer 19

Pyruvate
CO2
o2
ADP+pi
NADH2

Question 20

Name the molecules that sow net movement out of the the mitochondria

Answer 20

H20
ATP
NAD

Question 21

Explain why anaerobic respiration yields less ATP than aerobic

Answer 21

Anaerobic is the incomplete breakdown of glucose only producing 2 molecules of ATP per glucose molecule as energy still remains in lactate and ethanol, and oxygen does not act as the terminal electron acceptor

Question 22

Describe the process of anaerobic respiration in animal cells

Answer 22

Pyruvate becomes the terminal electron acceptor, where it is reduced and accepts the H+ from NADH2 and is converted into lactate

Question 23

State the way in which anaerobic respiration in a yeast cell differs from that in the animal cell

Answer 23

In yeast cells ethanol and carbon dioxide are produced in animals lactate is produced

Question 24

Which part of aerobic respiration can lead to greater ATP production

Answer 24

Krebs cycle

Question 25

Give a reason why ATP is used in the process of glycolysis

Answer 25

ATP activates glucose to convert into hexose biphosphate by accepting the Pi from the ATP

Question 26

What provides the electrons in respiration

Answer 26

NADH2