Key Concepts 18

Question 1

state and describe four stages of glycolysis

Answer 1

phosphorylation. using making hexose bisphosphate

lysis making triose phosphate

phosphorylation making triose bisphosphate

dehydrogenation and formation of 4 ATP, 2NADH and two pyruvate

Question 2

state and describe four stages of respiration and where they occur

Answer 2

Glycolysis cytoplasm
Oxidative decarboxylation matrix
Krebs matrix
Oxidative phosphorylation cristae

Question 3

how does pyruvate enter the mitochondrial matrix

Answer 3

by active transport via specific carrier proteins

Question 4

describe the steps of oxidative decarboxylation

Answer 4

pyruvate undergoes oxidative decarboxylation. so H is removed and CO2 is removed

removed hydrogens are donated to NAD to make one NADH per pyruvate molecule (the used in OP)
acetyl group made binds to CoA to make 2C acetyl CoA

Question 5

what happens to the CO2 removed from oxidative phosphorylation?

Answer 5

either diffuse away and be removed from the organism as metabolic waste, or in autotrophs it could be used as a raw material in photosynthesis

Question 6

the steps of the Krebs cycle

Answer 6

CoA is removed. then the 2C acetyl group reacts with 4Coxaloacetate to make 6C citrate

citrate undergoes decarboxylation and dehydrogenation to make 1 red NAD and CO2. making 5C compound

5C compound undergoes further decarboxylation and dehydration reactions. after 2 rounds and CO2& NADH ATP FADH then NADH, oxaloacetate is regenerated

Question 7

two parts of respiration that include substrate level phosphorylation

Answer 7

Krebs

Glycolysis

Question 8

importance of Coenzymes in respiration

Answer 8

transfer protons
electrons
and functional groups between many of the enzyme catalysed reactions

Question 9

what are coenzymes derived from?

Answer 9

vitamins. Coenzymes are mostly recycled and vitamins are an essential micronutrients

Question 10

describe the role of NAD

Answer 10

• takes part in all stages of cellular respiration
• accepts one hydrogen
• oxidised at the start of the ETC releasing protons an electrons
• make 3ATP

Question 11

describe the role of FAD

Answer 11

• only accepts hydrogen in the krebs cycle
• accepts two hydrogens
• oxidised further along the ETC releasing protons an electrons
• makes 2 ATP

Question 12

describe the process of OP

Answer 12

H atoms that have been collected by FADH and NADH are delivered to ETC present in the membranes of the cristae of the mito

h atoms dissociate into hydrogen ions and electrons. those electrons used to make ATP by chemiosmosis and energy released during redo reactions as the electrons reduce and oxidise the electron carriers ass they flow along the ETC .

energy used to make a proton gradient therefore there’s a diffusion of protons through atp synthase so makes ATP

at the end of the etc, electrons combine with h+ and oxygen to make water. Oxygen is the final electron acceptor and the ETC cant operative without oxygen present.

Question 13

why respiration is described as aerobic

Answer 13

requires the full breakdown of glucose and therefore aerobic

Question 14

why doesn’t the hydrogen released from NAD and FAD combine directly with 02 to released energy as the bonds that make up H20 are formed?

Answer 14

the energy wouldn’t be used to make ATP

Heat released in the exothermic reaction would just raise the temperature of the cell

Question 15

how is substrate level phosphorylation different to oxidative phosphorylation

Answer 15

couples the flow of protons own the electrochemical gradient through ATP synthase to the phosphylation of ADP to make ATP

Question 16

ATP production of anaerobic vs aerobic respiration

Answer 16

2 vs 38

Question 17

When does anaerobic respiration occur

Answer 17

Oxygen can’t be supplied fast enough to the cells or
When theres no oxygen
To keep vital processes functioning

Question 18

Why does anaerobic produce less atp that aerobic

Answer 18

The organic compound, eg glucose, aren’t fully broken down

Question 19

Where does alcoholic fermentation occur

Answer 19

Yeast and some plant root cells

Question 20

Where does fermentation occur

Answer 20

Animal cells

Question 21

What happens when theres no oxygen to act as the final electron acceptors at the end of the etc

Answer 21

Flow ofnelectrons stop and making atp by chemosmosis stops too
Red NAd and fad aren’t able to be oxidised as theres nowhere for their electrons to go so the nada and fad cant be regen. Link and Krebs stop because no coenzyme to accept the H being removed

Question 22

Describe the process of lactate fermentation in mammals

Answer 22

Pyruvate can act as a hydrogen acceptor from the nad
Catalysed by lactate dehydrogenase
Pyruvate to lactate and NAD regent to keep glycolysis going
Aerobic is still happening

Question 23

What happens to the lactic acid that made in fermentation

Answer 23

Converted back to glucose in the liver but oxygen needed for this process, jence the oxygen debt and need to breath heavy after exercise

Question 24

Why lactate fermentation can occur forecer

Answer 24

Reduced quantity of ATP made not nuff to maintain vital process for a long time

Accumulation of lactic acid causes decrease pH leading to dentures enzymes . Respiratory enzymes and muscles filaments are made from proteindnand will not fiction at low ph

Question 25

How does increasing fitness affect lactate fermentation

Answer 25

Increases blood supply and flow through muscles

Increases rate of lactic acid removal and intensity and duration of exercise can increase

Question 26

Alcohol fermentation

Answer 26

Irreversible
Can happen forever
Ethanol is a toxic waste product to yeast
Can’t survive in over 15 percent ethanol which is allowed to happen in wine makeonh

Question 27

Why do lipids release more ATP in respiration than carbs

Answer 27

They have a greater proportion of CH bonds

Question 28

Why lipids have a lower rq than carbs

Answer 28

They hive more CH bonds that require more O to break them down, lipids releases relatively less CO2

Question 29

How to determine the substrate being used

Answer 29

Measure the vol of o2 in and CO2 out suring resp of a particular substrate. Measure rq and you can roughly determine

Question 30

Whats the value of rq during anaerobic and why

Answer 30

Over one. But not easy to measure as the point anaerobic starts isn’t easy to pinpoint