Note!

Please see 3.7 Cell Respiration Core prior to using this presentation.

Assessment Statements

8.1.1 State that oxidation involves the loss of electrons from an element, whereas reduction involves a gain of electrons; and that oxidation frequently involves gaining oxygen or losing hydrogen, whereas reduction frequently involves losing oxygen or gaining hydrogen.

8.1.2 Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP formation.

8.1.3 Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs.

8.1.4 Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen.

8.1.5 Explain oxidative phosphorylation in terms of chemiosmosis.

8.1.6 Explain the relationship between the structure of the mitochondrion and its function.

8.1.1

State that oxidation involves the loss of electrons from an element, whereas reduction involves a gain of electrons; and that oxidation frequently involves gaining oxygen or losing hydrogen, whereas reduction frequently involves losing oxygen or gaining hydrogen.

OILRIG

Oxidation Is LossReduction IsGain

Loss and gain of what?

Oxidation Reduction

XX

X+X+X

X X

X X

X

X+ e-

+ O2O O

H + H+ H

electrons

+ e-

oxygen

+ O2

hydrogen

+ H+ X

Respiration involves oxidation and reduction.

An organic compound (glucose) is oxidised

while ADP is reduced to ATP

In cell processes biochemical processes

are coupled to the oxidation of ATP to ADP

8.1.2

Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP formation.

Aerobic respiration, gives a higher yield of

ATP.

ADP + Pi

ATP

Aerobic respiration

glycolysis link reaction

Kreb’s cycle

electron transport chain

oxidative phosphorylation

Glycolysis (sugar splitting)

CC

CC

C C C C

C

CC

CC

C C C C

C

CC

C

CC

C

Glucose 6C

PP

P

P

CYTOPLASM

ATP

ADP + Pi

phosphorylation

lysis

oxidation

2 x 3C pyruvate

NAD+

NADH+ + H+

Phosphorylation

2 ATP

2 ADP + Pi

Energy

Time

There is an increase in

energyPhosphorylation uses 2 ATP to add 2 phosphate groups to glucose.

This makes the glucose molecule more unstable so it becomes easier to break bonds.

The phosphate groups also allow the hexose bisphosphate to bind more effectively with its enzyme.

Lysis

hexose diphosphate

triose phosphate

Triose phosphate or TP is an intermediate in many biochemical reactions.The phosphate groups help the TP to bind to its enzyme.

Oxidation (ATP formation)

NAD+

NADH+ + H+

2 ADP + Pi

2 ATP

There are 2 TP molecules made from each glucose.

A total of 4 ATP molecules are made.

But, we used 2 during phosphorylation.

So, we have a net production of 2 ATP

reduction oxidation

What is NAD+?

Watch the video and then summarise of the key points of glycolysis

Summary

Takes place in the _________

No _________ needed

6C ________ is converted into 3C _________

__ ATP made and __ ATP used

Net gain

2 ATP

2 NADH+ + 2H+

2 3C pyruvate

cytoplasmoxygen

glucose pyruvate

4 2

8.1.3

Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs.

8.1.6

Explain the relationship between the structure of the mitochondrion and its function.

Mitochondria

Site of aerobic respiration

Pyruvate is further oxidised to release more ATP.

Only found in eukaryotic cells.

Cells that need a lot of energy will have many mitochondria ( liver cell) or can develop them under training (muscles cells).

Features of mitochondria

Surrounded by a double membrane.

Inner membrane folded to form 'cristae'. LSA for ATP production.

Space between the two membranes which is narrow creating a place to concentrate H+

The inner space is called the matrix.

It contains the enzymes needed for respiration.especially those of the Kreb’s cycle.

An example of compartmentalisation (isolation of substances needed for a particular function)

Mitochondria also contain some of their own DNA (mDNA). http://genome.wellcome.ac.uk/doc_WTD020876.html

PPQ Review

(a) Draw a labelled diagram showing the structure of a mitochondrion as seen in an electron micrograph (4)

(b) Explain the relationship between the structure of the mitochondrion and its function (3)

(a) Award marks for any of the following clearly drawn and correctly labelled.

cristae;

inner membrane;

outer membrane;

intermembrane space;

matrix;

ribosomes;

DNA; 4 max

(b) cristae provide surface area for oxidative phosphorylation;

inner membrane contains electron transport chains/ATP synthase (which

carry out oxidative phosphorylation);

outer membrane separates the mitochondrion from the rest of the cell;

mitochondrial DNA/ribosomes make (mitochondrial) proteins;

small volume intermembrane space allows for higher concentration

of protons;

matrix has enzymes for the Krebs cycle; 3 max

8.1.4

Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen.

Link Reaction

CoA

NAD+

NADH + H+C

CO2

C C

CoA

Acetyl CoA

Decarboxylation - removal of carbon from the pyruvate

Carbon forms carbon dioxide

2C Acetyl group binds temporarily with Coenzyme A

Kreb’s Cycle

C C

CC C C

CC C C C C

citric acid

CC C C C

NAD+

NADH + H+

C CO2

CC C C

NAD+

NADH + H+

C

CO2

NAD+

NADH + H+

FADFADH2

ADP + Pi

ATP

This is a metabolic cycle.

Each step requires enzymes to reduce the activation energy.

The reactions take place in the mitochondrial matrix.

This reaction occurs within the matrix where each intermediate becomes the substrate for the next step.

Watch this:

8.1.5

Explain oxidative phosphorylation in terms of chemiosmosis.

Watch these:

Task

Reorder the sentences in the booklet to explain the process of chemiosmosis

(answers on the next page)

The inner membrane is folded into cristae and

embedded in this membrane are proteins

which form an electron transport chain

Reduced NAD+ and FAD are oxidised releasing electrons and H+ ions.

The electrons are passed along the chain while the

H+ are pumped by the membrane proteins into the inner membrane space.

These H+ ions accumulate and their concentration increases.

When they diffuse back to the matrix they pass through

a membrane protein called ATP synthase.

The flow of electrons through ATP synthase

drives an enzyme reaction which converts ADP + Pi to ATP.

ATP synthase is an enzyme embedded in the cristae membrane.

H+create an electrochemical gradient (chemical potential energy).

The H+pass through a channel in the enzyme driving the motor.

The motor spins bringing together ADP and Pi to produce ATP

NADH + H+, FADH2, O2

ATP, H2O, NAD+, FAD