Bell Task

1
Bell Task

• Write down 3 features of mitochondria which help
  them carry out respiration.
• Name the useful substances produced in the Krebs
  cycle.
• Name the 3 stages of oxidative phosphorylation.
• Explain the term chemiosmosis.

2
Homework Problem Areas

• ATP as a universal energy currency.
• Uses of ATP in plant cells.

3
Today..

• Anaerobic pathways
• Respiratory substrates and RQ
• Respirometer

4
Anaerobic Pathways

• Oxidative phosporylation cant happen without
  oxygen
• Glycolysis does happen
• Lactate or Ethanol pathway follows glycolysis so
  H carriers can be reused.

5

• How many ATPs can be made per glucose in the
  anaerobic pathways?

6
Which pathway?

• Ethanol yeast and some plant tissues
• Alcoholic fermentation
• Lactate pathway other microbes and mammalian
  muscles when oxygen deprived

7
Pathways page 12

• Both pathways involving providing a H acceptor

8

• Ethanol pathway not reversible
• Lactate can be reversed
• liver converts it back to pyruvate
• or liver oxidises it to carbon dioxide and water
• Or liver converts it to glycogen
• Oxygen needed to get rid of lactate oxygen debt

9
Aerobic vs Anaerobic
10
Respiratory substrates

• Name the 3 possible respiratory substrates for
  cells.
• Explain why having more H in a substrate
  increases its energy value.
• Name the substrate with the greatest energy
  density.
• Name the piece of apparatus used to determine the
  energy value of a substrate

11
RQ

• Compares oxygen used to carbon dioxide produced
• Glucose produces 11 ratio
• Other substrates differ
• Write down RQ formula
• List RQ values for the 3 substrates.
• What does a high RQ value indicate?
• Answer SAQ 1.8 (hint balanced equation)

12
Respirometer

• Produce a labelled diagram of a respirometer and
  explain why the following are involved
• Soda lime
• U tube containing fluid.
• Control tube with glass beads
• Syringe with a tap (on the control tube)