1. (7) Cellular Respiration
(E) Regulation of pathways through feedback inhibition
(A) Role of ATP & Phosphorylation
(B)
The metabolic pathway of respiration: Glycolysis and the citric acid cycle
(C) The metabolic pathway of respiration: electron transport chain & ATP synthesis
(D)
Substrates for Respiration

2. Cellular Respiration (d)
State 5 alternative substrates for respiration and in which stage(s) they can be used

3. Glucose the substrate Think of this paperclip as glucose
During cellular respiration, this glucose molecule is broken down.
But what if glucose was not available? Would the cell still be able to carry out respiration?
YES!!!
(if you said ‘no’ you just killed that organism! No respiration = no life!)

4. Alternative substrates: Carbohydrates
Glucose :
Maltose :
Simple sugar
Simple sugar
Starch :
Sucrose :
Complex carbohydrate stored in plants
Simple sugar
Starch and glycogen are broken down to glucose for use as a respiratory substrate.
Other sugar molecules can be converted to glucose or glycolysis intermediates for use as respiratory substrates.
Glycogen :
Complex carbohydrate stored in animals in the LIVER

5. Demo: Investigating the use of 3 different sugars as a respiratory substrate
Read pages 108 and 109 before setting up the experiment

7. Alternative substrates: Fats
Fats can also be broken down into 1 glycerol and 3 fatty acid molecules.
These are intermediates of glycolysis and the citric acid cycle.

8. Alternative substrates: Proteins
Proteins can be broken down to amino acids and converted to intermediates of glycolysis and the citric acid cycle for use as respiratory substrates.
Proteins are only used as an energy source as a last resort when the body has used up all other respiratory substrates, such as carbohydrates and fats (in cases such as starvation or anorexia)

9. Tasks Copy diagrams: 7.18 on page 107 7.19 on page 108
Read the case study on page 110 and 111
Make a summary note on ‘the use of respiratory substrates during exercise and starvation’

10. Cellular Respiration (d)
State 5 alternative substrates for respiration and in which stage(s) they can be used