OCR A2 Biology F214 - Respiration

Everything you need to know about respiration. Comment with anything you think needs either editing or adding into the document. Thank you!

HideShow resource information
Preview of OCR A2 Biology F214 - Respiration

First 489 words of the document:

A2 F214 Respiration Revision Notes
Active Transport - Moving ions and molecules across a membrane against a concentration gradient e.g. Na+/K+ pump.
Activation of Chemicals - E.g. glucose is phosphorylated at the beginning of respiration to make the molecule unstable and
easier to break down.
Anabolic Reaction - Synthetic reactions where small molecules are built up into larger more complex molecules (Usually
requiring ATP).
Adenosine Triphosphate - High energy compound, it is a phosphorylated nucleotide and is known as universal energy
Autotroph - An organism that makes its own food using simple inorganic molecules, such as carbon dioxide, water and
Catabolic Reaction - Break down reactions where larger more complex molecules are hydrolysed into smaller ones (Usually
requiring yielding).
Chemiosmosis - Diffusion of ions though a partially permeable membrane. It refers to the flow of H+ ions (protons) across a
membrane, which is coupled to generate ATP during respiration.
Dehydrogenation - The removal of Hydrogen from a molecule from a substrate molecule -always catalysed by a
Dehydrogenase Enzyme.
Endocytosis - Bulk movement of large molecules or substances into cells (requiring ATP) e.g. phagocytosis.
Energy - Is the ability to do work. It is measured in joules or kilojoules. (The potential to do jobs in the body).
Heterotroph - An organism that gains its nutrients from complex organic molecules. It digests them to simpler, soluble
molecules and then respires some of them to obtain energy, or uses the products of digestion to synthesise the organic
molecules it needs.
Hydrogenation - The addition of Hydrogen to a molecule (equivalent to `Reduction')
Hydrolysis - An enzyme-catalysed reaction which splits large molecules into smaller molecules with the addition of water.
Oxidation - A chemical reaction involving the loss of electrons, gain of oxygen or loss of hydrogen atoms.
Reduction - A chemical reaction involving the gain of electrons, gain of hydrogen atoms or loss of oxygen atoms.
Replication - Of DNA and organelles before cells divide.
Respiratory Substrate - An organic molecule which is broken down in respiration to release energy; for example lipids,
carbohydrates, proteins etc.
Secretion - Large molecules exported by exocytosis e.g. secretion of insulin by cells.
Substrate Level Phosphorylation - When a phosphate group (Pi) from an organic molecule is added to an ADP to form ATP-it
does not rely upon chemiosmosis and ATP synthase.
Synthesis - Of large molecules from smaller ones e.g. proteins from amino acids.
ATP and NAD structure -
`ATP' is Adenosine Triphosphate, it is formed from a Ribose Sugar, Adenine base and 3 phosphate groups, and it therefore
looks very much like a nucleotide.
ATP is the `universal energy currency', moving small amounts of energy between processes in the cell.

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

ATP is constantly being recycled between ADP + Pi ATP. When ADP has Pi added to it the bond between them is able to
store 30.6 KJ of energy, when the bond is broken ATP ADP + Pi this energy is released to do `work'.
Energy is released immediately into the cells in small, manageable amounts that will not damage the cell and will not be
Energy is needed for all the reactions that take place within an organism, collectively known as metabolism.…read more

Page 3

Preview of page 3

Here's a taster:

The hydrogen atoms are combined with coenzymes such as NAD. These carry the hydrogen atoms, which can
later be split into hydrogen ions and electrons, to the inner mitochondrial membranes. Here they will be involved in the
process of oxidative phosphorylation, which produces a lot of ATP. Delivery of the hydrogens to the cristae reoxidises the
coenzymes so they can combine with more hydrogen atoms from the first three stages.…read more

Page 4

Preview of page 4

Here's a taster:

Hexose Bisphosphate (6C) then splits into two molecules of Triose phosphate (3C).
4. In a series of reactions, each molecule of triose phosphate is converted into Pyruvate or pyruvic acid (3C).
5. During this series of reactions, enough energy is released to make 4 ATP molecules per triose phosphate.
There is a net gain of 2 ATP molecules when one glucose molecule is split by glycolysis.
6.…read more

Page 5

Preview of page 5

Here's a taster:

The reduced NAD is used in the final stages of aerobic respiration ­ Oxidative Phosphorylation.
The CO2 is given off as a waste gas.
2 Pyruvate + 2 NAD+ + 2 CoA 2 CO2 + 2 Reduced NAD + 2 Acetyl CoA
NAD+ indicates NAD in the oxidised state. Two molecules of pyruvate are considered in the equation as two molecules of
pyruvate are derived from each molecule of glucose. No ATP is produced.…read more

Page 6

Preview of page 6

Here's a taster:

The 5C compound is Dehydrogenated and Decarboxylated to form a 4C compound (Succinate), CO2 and
reduced NAD is formed.
5. At this stage, enough energy is released to form a molecule of ATP by Substrate level phosphorylation.
6. The 4C compound is Dehydrogenated to form another 4C compound intermediate (Malate), this time the
carries FAD picks up the hydrogen and becomes Reduced FAD.
7. Finally the 4C compound (Malate) is Dehydrogenated to form a 4C compound called Oxaloacetate, reduced
NAD is formed.
8.…read more

Page 7

Preview of page 7

Here's a taster:

Enough energy is released at 2 stages to make ATP from ADP and Pi.
7. The electrons are passed along a chain of electron carriers and then donated to molecular oxygen.
8. As electrons flow along the ECT, energy is released and used by coenzymes associated with some of the electron
carriers to pump the protons across to the intermembrane space.
9.…read more

Page 8

Preview of page 8

Here's a taster:

When there is a limited supply of O2 for respiration all four stages stop!
This is because without O2 to act as the Final Hydrogen Acceptor all the NAD stays reduced as reduced NAD.…read more

Page 9

Preview of page 9

Here's a taster:

Mitochondria ­ are organelles found in eukaryotic cells. They are the sites of aerobic stages of respiration i.e. Link Reaction,
Krebs Cycle and Oxidative Phosphorylation.…read more

Page 10

Preview of page 10

Here's a taster:

Adaptations of the mitochondrion to Respiration:
1. Ribosomes to allow synthesis of proteins required for respiration, e.g. ATPsynthase.
2. Loop of DNA which codes for the proteins required for respiration, e.g. ATP synthase and dehydrogenase
3. Enzymes required for the Krebs Cycle, Dehydrogenase and Decarboxylase, are at high concentration in the liquid
4. The Mitochondria is surrounded by a double membrane - inner and outer.…read more


No comments have yet been made

Similar Biblical Hebrew resources:

See all Biblical Hebrew resources »See all resources »