Chapter 6

Question 1

Cellular respiration

Answer 1

Allows cells to break down the high-energy molecule ATP
Aerobic cellular respiration OR anaerobic fermentation

Question 3

Cellular respiration process

Answer 3

1. Glycolysis
2. The Krebs cycle
3. The electron transport chain

Question 4

Mitochondria

Answer 4

Double membrane bound organelle that is the site of the second and third stages of aerobic cellular respiration
Matrix (2nd stage)
Cristae (3rd stage)
Outer membrane
Inner membrane

Question 5

Glycolysis

Answer 5

1st stage of cellular respiration
Occurs in cytosol
Breakdown of 6 carbon glucose to 3 carbon pryuvate molecules
2ADP + 2Pi = 2ATP
glucose = 2 pryuvate
2NAD+ + 2H+ = 2NADH

Question 6

difference between aerobic and anaerobic

Answer 6

Aerobic - oxygen available
Anaerobic- no oxygen

Question 7

The Krebs cycle

Answer 7

generates lots of high energy and proton carriers
Occurs in the matrix

Question 8

The link reaction

Answer 8

Link glycolysis and Krebs cycle
2 acetyl-CoA = 4 carbon dioxide
2ADP + 2Pi = 2ATP
6NAD+ + 6H+ =6NADH
2FAD + 4H+ = 2FADH2

Question 9

Electron transport chain

Answer 9

Majority of ATP is produced in the process of aerobic cellular respiration
Occurs in cristae
6 oxygen = 6 water
26 or 28 ADP + 26 or 28 Pi = 32 or 34 ATP
10NADH = 10 NAD+ + 10H+
2FADH2 = 2FAD + 4H+

Question 10

Overall production of atp from aerobic cellular respiration

Answer 10

Glycolysis produces 2 ATP
Krebs cycle produces 2 ATP
electron transport chain produces 26 or 28 ATP

Question 11

Anaerobic fermentation

Answer 11

Involves the breakdown of glucose and ATP production via glycolysis in the absence of oxygen.it allows for the replenishment of nad+ for continued use in glycolysis

The conversion of pyruvate to lactic acid in animals and to ethanol and carbon dioxide in yeast.

Question 12

Anaerobic fermentation in animals

Answer 12

. When oxygen availability is insufficient animals undertake lactic acid fermentation after glycolysis
Glucose = 2 lactic acid + 2ATP

Question 13

Anaerobic fermentation in yeasts

Answer 13

Involves glycolysis, but pyruvate is instead converted to ethanol and carbon dioxide
2 ethanol + 2CO2 + 2ATP

Question 14

Biofuel from fermentation

Answer 14

Biofuels are made from organic materials known as biomass, which is plant and animal material that can be sourced from many existing industries
Renewable

Question 15

Carbon neutral

Answer 15

A state in which there is no net release of carbon dioxide into the atmosphere

Question 16

Steps of creating biofuel

Answer 16

1. Deconstruction - the biomass is treated to help break it down to make the fermentation process more efficient
2. Digestion by enzymes - the broken down biomass is then exposed to enzymes which break down the starch and cellulose and convert them into glucose and other sugars
3. Ethanol fermentation - yeast is used to facilitate the anaerobic fermentation of the sugars
4. Purification and dehydration - ethanol is distilled via the removal of water therefore biofuel

Question 17

Bioethanol

Answer 17

Derived from fermentation of plant sugars

Question 18

Biodiesel

Answer 18

Produced via the formation f fatty acids from natural oils

Question 19

Implications of bio fuel

Answer 19

→ sustainability
→ carbon neutrality

Pros: climate impact
Energy security
Localised energy

Cons: food vs fuel
Cost and availability