Respiration

Question 1

3 Enzyme-controlled pathways in Aerobic Respiration

Answer 1

Glycolysis, Krebs Cycle, Electron transport chain

Question 2

Glycolysis 1st chemical pathway (Aerobic + Anaerobic) “doesn’t require O2”

Answer 2

Occurs in the Cytoplasm of the cell. - Each glucose molecule is broken down into 2 pyruvate molecules.
- 2 molecules of ATP are produced in the break down.

Question 3

Aerobic Respiration Equation

Answer 3

Glucose + Oxygen —–> Carbon Dioxide + Water + Energy

Chemical Equation:
C6H12O6 + 6O2 –> 6CO2 + 6H2O + 38ATP

Question 4

Krebs Cycle stage 2

Answer 4

Occurs in the Matrix ( secreted with enzymes) of mitochondria
- cyclic series of enzyme controlled reactions using the products of glycolysis (pyruvate) and produces H and CO2 atoms.
- ONLY occurs if OXYGEN is present
- CO2 is released as a waste product ( we breathe it out and it goes to our blood stream and diffuses through our lungs and out through our nose)
Carrier H+ electron molecule to ETC:
- NAD+ —> NADH (Co enzyme)
- 2ATP created

Question 5

Electron Transport Chain (ETC)
Final stage

Answer 5

Occurs in the Cristae ( folds of inner membrane)
- the H atoms are ionised and their energy is used to form ATP from ADP.
At the end of the ETC, the electrons are returned to the H ions which become atom and combine with 02 and forms H2O water as a by produced which is sweated out or urinated.
- produces the most 34 ATP finally 38 ATP is produced total .

Question 6

Parts of Mitochondria

Answer 6

Outer Membrane

Inner membrane ( Cristae) :
Contains multiple folds which increases the surface area of the membrane which increases the efficiency of ETC as it allows for a longer i.m. and therefore more ETC can happen at the same time)

Matrix:
Space within the inner membrane, secreted with multiple enzymes used in the ETC.

Question 7

Anaerobic Respiration ( just 1 step)
NO OXYGEN REQUIRED

Answer 7

Occurs in the Cytoplasm of the cell
- glucose breaks down into pyruvate and only produces 2 ATP
- pyruvate acid -> ethanol and CO2 in plants
-pyruvic acid -> lactic acid in animals
Lactic acid build up causes muscle fatigue and cramps and could be harmful to humans

Question 8

Anaerobic Respiration Equation

Answer 8

Glucose —> Lactic acid + 2 ATP
C6H12O6 —> CH3CHCOOH + 2ATP

Question 9

Advantages/ Disadvantages of Aerobic vs Anaerobic