A level Respiration

1. Respiration – A2
A Stangroom

2. Life requires a continuous supply of
energy.
Organic molecules can be used as building
blocks or as potential chemical energy
which is released from the breakdown of
molecules in respiration
This energy is used to do work

3. Energy is required in the form of
ATP

4. ATP ADP + Pi + 30.5 KJ mol-1
ADP AMP + Pi + 30.5 KJ mol-1
AMP Adenosine + Pi + 14.2 KJ mol-1
ATP + H2O ADP + H3PO4 + 30.5 KJ mol-1
At rest an average person uses 40Kg of ATP in 24
hours only 5g is present at any time
During exercise ATP is broken down at the rate of
0.5g per minute

5. ATP is the universal intermediary
molecule
between energy yielding and energy
requiring cell reactions
energy currency
transfer is inefficient; some is lost as
thermal energy
Energy storage molecules are:
Long term: glycogen, starch, fat
Short term: glucose, sucrose

6. Energy is required for WORK :
Anabolic reactions (synthesis)
e.g. amino acids proteins
Active transport
Movement against diffusion gradient
e.g.sodium/potassium pump

7. Movement
cilia, flagella, cytoplasmic streaming and
muscles
Energy is used to bring about the movement
of two protein strands relative to each other
Muscle made of
muscle fibres, made
of bundles of
myofibrils
They are elongated
cells containing
myofilaments – actin
and myosin

8. actin (thinner) and myosin (thicker) are protein
strands
The cells also have many mitochondria
And specialised ER called sarcoplasmic reticulum
which releases calcium
Myosin has a rod shaped region attached to a
globular head that acts as ATP-ase
the head can attach to actin
Actin is made of two helical protein strands twisted
together
myosin
Actin