Unit 1 Learning Outcomes
Section C- Energy Release
Content
A. The role and production of ATP.
Notes
LO 1. State what the initials ATP, ADP and Pi ATP
is
Adenosine
Triphosphate.
stand for.
Composed of one adenosine molecule and
three inorganic phosphate molecule. The
LO 2. Explain the role of ATP in living cells.
third phosphate is joined by a high
energy bond. When broken energy is
LO 3. Explain the relationship between ADP, Pi released.
and ATP energy, and write this relationship as When energy is released and the third
an equation.
phosphate is broken off you are left
with ADP (Adenosine Diphosphate) and
an inorganic phosphate.
When other molecules are broken down
(oxidised) energy is released. This
energy can be used to join the inorganic
phosphate onto the ADP.
ATP is found in all living cells and is the
immediate source of energy for most
biological
reactions
(muscular
contraction, active transport, nerve
conduction, cell division etc).
Extra
B. Glycolysis.
Respiration is the process by which
energy is released from a foodstuff by
oxidation.
LO 4. Name the most common respiratory Metabolism is the sum of all the
substrate and give other respiratory chemical processes in a living organism.
substrates used in exceptional circumstances. Respiration occurs in 3 stages:
Glycolysis, Krebs cycle and the
LO 5. Describe the breakdown of glucose (6C) cytochrome system.
to pyruvic acid (3C) with a net production of
ATP.
Glycolysis occurs in the cytoplasm of
the cell.
LO 6. Complete the equation for aerobic Glucose is the most common substrate
respiration.
for glycolysis but fats and proteins can
also be used.
LO 7. Name the three stages in aerobic Glucose: C6H12O6
respiration.
Glycolysis means splitting glucose. 6
carbon glucose is split into two 3 carbon
LO 8. State where each stage of aerobic Pyruvic acid molecules.
respiration occurs in cells.
This uses 2 ATP molecules and produces
4 ATP molecules. Meaning a net gain of
LO 9. Describe the first stage of aerobic 2ATP’s.
respiration, glycolysis (equation, raw materials, Hydrogen is released during glycolysis
products, location, carbon count).
which is accepted by NAD (nicotinamide
adenine dinucleotide) becoming NADH2
LO 10. Explain how the process of respiration Oxygen is not required for glycolysis.
is involved in the regeneration of ATP.
C. Krebs (Tricarboxylic acid, Citric acid) cycle. Krebs cycle takes place in the matrix of
The production of carbon dioxide and the mitochondria.
hydrogen.
Pyruvic acid is converted into a 2 carbon
acetyl group and carbon dioxide is
LO 11. Describe the second stage of aerobic released.
respiration, Krebs cycle (equation, raw Acetyl group combines with coenzyme A
materials, products, location, carbon count)
to give acetylCo A.
This combines with a 4 carbon compound
to form a 6 carbon compound, Citric
acid.
Citric acid is converted into a 5 carbon
and then the original 4 carbon
compound.
Each time a carbon is lost it is released
as carbon dioxide. Hydrogen is also
released. This is collected by NAD to
become NADH2.
The final 4 carbon compound completes
the cycle by reacting with the next
acetylCo A.
This is an aerobic phase of respirationOxygen is required. This is because the
hydrogen released cannot leave the
system without a final acceptor. Oxygen
is the final acceptor, creating water.
D. The cytochrome system.
The production of ATP and water.
The hydrogen from earlier stages is
LO 12. Describe the third stage of aerobic carried to the cytochrome system. The
respiration, Cytochrome system (diagram, raw cytochrome system is found attached to
materials, products, location).
each cristae.
The hydrogen is passed along a series of
carriers. At each step enough energy is
released to synthesis one ATP from ADP
and Pi.
Oxygen is the final hydrogen acceptor,
creating water.
E. Mitochondrion structure
A mitochondrion is a sausage shaped cell
LO 13. Describe and draw a mitochondrion organelle found in the cytoplasm. It is
organelle showing details of its structure,
bound by 2 membranes. The inner
membrane is folded into many plate-like
LO 14. Give examples of cells containing extensions
called
Cristae.
These
mitochondria,
increase the surface area. Cristae
project into the fluid-filled space called
the central matrix.
Each cristae is covered in stalked
particles where the hydrogen transfer
takes place.
F. Distinction between aerobic and anaerobic
phases of respiration with reference to the
level of ATP production and final metabolic
products.
If oxygen is present then respiration
can take place to its completion. Glucose
is fully broken down.
Glycolysis produces 2 ATP molecules.
The second stage produces 18 ATP
LO 15. State the number of molecules of ATP molecules per pyruvic acid, totalling 36
produced from aerobic respiration of 1 ATP’s. This gives a total of 38 ATP
molecule of glucose.
molecules from one glucose molecule.
LO 16. Describe the process of anaerobic I there is no oxygen then only glycolysis
respiration in plants and animals (equations, takes place, producing 2ATP’s in total
raw materials, products, location).
per glucose molecule.
LO 17. Compare the processes of aerobic
respiration and anaerobic respiration in cells
(equations, raw materials, products, ATP
produced, efficiency, location).
In animal cells anaerobic respiration
causes the pyruvic acid to be converted
into Lactic acid. This is a reversible
reaction, as lactic acid is converted back
into pyruvic acid in the presence of
oxygen. This is called an oxygen debt.
In plant cells anaerobic respiration
causes the pyruvic acid to be converted
into ethanol and carbon dioxide. This is
irreversible as carbon dioxide is lost to
the environment.
Anaerobic respiration is less efficient
than aerobic respiration.