RespirationEquation:

Oxidation / Reduction

• What is oxidation?

• What is reduction?

Key Idea: When something is reduced it gains electrons and protons. These electrons and protons have usually come from another chemical, so that chemical has been oxidised. Therefore a REDOX reaction has taken place. This is also true if something is oxidised it has lost electrons and protons. These have usually been given to another chemical, sothat chemical has been reduced. Therefore this is also a REDOX reaction.

Coenzymes – NAD+ and FADHas this been oxidised or reduced?

NAD+ + 2e- + 2H+ NADH + H+

FAD + 2e- + 2H+ FADH2

Structure of NAD and FAD

What biochemical group do they belong to?

Evidence?

Structure of ATPNucleic acid

Components:

Synthesized from?

Enzyme used?

Key Ideas – Why turn glucose into ATP?Glucose is already a form of potentialchemical energy, why turn it into ATP?• Lots of little packets of energy (ATP) can be made

and used for lots of little jobs in the cell. A job seldom requires all the energy contained in one molecule of glucose. (therefore efficient, not wasteful!!)

• ATP will release energy quickly, glucose will not, therefore it is an instant source of energy for the cell

ATP the Universal Energy CurrencyWhy universal?Why currency?

Enables a cell to do work3 examples:

Energy can be released quickly, only one bond needs to be broken.

Enzyme used:Bond broken:Energy per mole 30.6KJ

Other features, soluble and easily transported across membranes

Key Ideas - Making ATP• To make ATP a phosphate group (Pi) has to be

added to ADP, this reaction is called phosphorylation

ATP + Pi ATPThe energy to add the Pi group can come in three

different ways:1. Substrate level phosphorylation – use the energy

released from chemical reactions2. Oxidative phosphorylation – use the energy from

high energy electrons produced during oxidation reactions

3. Photophosphorylation – use the energy from high energy electrons produced using light energy

Substrate Level PhosphorylationIn respiration it is produced in this way during glycolysis and the Krebs cycle

Triose phosphate to Pyruvate – 4 ATP produced

5C to 4C compound – 1 ATP produced each turn

Key Ideas - Chemiosmosis• The energy from high energy electrons can be

used to produce a proton gradient• A proton gradient can be used to produce ATP,

this called chemiosmosis• As protons flow down the gradient, energy is

released, this energy is used to add a Pi group to ADP

• Chemiosmosis is used to produce ATP in respiration and photosynthesis

Key Enzymes• Dehydrogenases

Involved in what type of reactions?

Catalyze the removal of?

• DecarboxylasesInvolved in what type of reactions?

Catalyze the removal of?

Glycolysis• What does it mean?

• Where are ATP needed?

• Where are ATP produced?

• Where does it take place?

• What are the net products?

• Where can glycerol enter?

After Glycolysis……If no oxygen is available

•What happens to the pyruvate?

•Why?

•Useful products produced?

After glycolysis….

If oxygen is available….

•What is this reactioncalled?

•Where does it take place?

•Why is it described as anoxidative decarboxylation?

• Where can fatty acids enter?

After the Link reaction….• What is this series

of reactions called?

• Where does it takeplace?

• What useful productsare produced per glucose molecule?

Mitochondrial Structure

The Electron Transport Chain

The Electron Transport Chain• Why is it called this?

• Where do the electron come from?

• What do they release as they are passed along?

• What is this used for?

• pH /chemiosmosis / stalked particles (ATP synthetase)

Number of ATP molecules produced• NAD leads to the production of 3 ATP molecules• FAD leads to the production of 2ATP molecules

Why? – Carrier systems are different – NAD linked to 3 pumps and FAD 2 pumps

Stage of Respiration Number of red NAD produced

Number of red FAD produced

Number of ATP produced

Glycolysis

Link Reaction

Krebs Cycle

Summary of aerobic respiration?