State the stages of glycolysis where Task State the stages of glycolysis where ATP is used ATP is produced NAD is reduced

State the stages of glycolysis where: Task : 5 minutes State the stages of glycolysis where: ATP is used: ATP is hydrolysed and glucose is phosphorylated to form glucose 6-phosphate. ATP hydrolysed and fructose 6-phosphate is phosphorylated to produce fructose 1,6-bisphosphate. The energy from ATP activates the hexose sugar and prevents it from leaving the cell: hexose 1,6 bisphosphate

ATP is produced: During the oxidation of triose phosphate 2 molecules of ATP are formed by substrate level phosphorylation and when triose phosphate is converted to pyruvate another 2 molecules of ADP are phosphorylated to 2 molecules off ATP NAD is reduced: During the oxidation of triose phosphate 2 hydrogen atoms are removed from each TP molecule to produce 2 molecules of reduced NAD

Learning outcomes: Explain, with the aid of diagrams and electron micrographs, how the structure of mitochondria enables them to carry out their functions Ensure you collate yourself good labelled diagrams and EM of Mitochondria I have put 3 slides from OCR next to help you in this.

Structure of a mitochondrion © Pearson Education Ltd 2009 This document may have been altered from the original

Diagram showing the structure of the inner membrane and the flow of electrons between electron carriers and the flow of protons into the intermembrane space © Pearson Education Ltd 2009 This document may have been altered from the original 6

The structure of ATP synthase © Pearson Education Ltd 2009 This document may have been altered from the original 7

Where does cellular respiration take place? Glycolysis: cytoplasm The rest in Mitochondria........ TASK: Draw and annotate a mitochondria SYNOPTIC

Have an inner and outer phospholipid membrane making up the envelope The folds are called cristae/ crista Inner folded membrane Outer smooth membrane THE POWERHOUSE OF THE CELL The surfaces of the cristae are studded with minute spheres Intermembrane space Fluid matrix of inner compartment

Stalked particles on inner surface of cristae: ATP synthesis The matrix: Mixture of proteins and lipids site of Krebs cycle and link reaction (enzymes) Ribosomes: use mitochondrial DNA to synthesise proteins and enzymes Intermembrane space: H+ ions accumulate to set up concentration gradient (chemiosmosis) Stalked particles on inner surface of cristae: ATP synthesis ATPase Cristae: greatly increases surface area allowing more electron transport chains: oxidative phosphorylation + synthesis of ATP Outer membrane: controls entry/exit of substances e.g carbon dioxide, pyruvate

Mitochondrial matrix This is where the link reaction and the Krebs cycle take place It contains Enzymes Molecules of coenzyme NAD Oxaloacetate (4C compound that accepts acetate from the link reaction) Mitochondrial DNA Mitochondrial ribosomes

Outer Membrane Phospholipid layer It contains Protein channels or carriers to allow pyruvate to pass through Other proteins act as enzymes

Inner membrane Has a different membrane structure and is impermeable to small ions (e.g. hydrogen ions) Folded into cristae to give a large surface area Contains electron carriers and ATP synthase enzymes

ATP Synthase enzymes: good link watch Large and protrude from inner membrane into matrix Known as stalked particles Allow protons through (H+) Protons flow down a proton gradient (chemiosmosis) From intermembrane space to matrix The force drives the rotation part of the enzyme and allows formation of ATP from ADP and Pi

Electron Transport chains: Each electron carrier is an enzyme Enzymes with non protein haem cofactors (containing iron) The iron atoms become reduced Fe³+ to Fe²+by accepting an electron (e-) then re-oxidised to Fe³+ by passing the electron onto the next carrier Oxidoreductase enzymes are involved in the oxidation and reduction reactions Electron carriers also have a coenzyme that pumps hydrogen ions from the matrix into the intermembrane space: energy from where?? Inner membrane is impermeable to small ions the protons accumulate in the intermembrane space (lower pH)

Tasks Can you draw and label a mitochondria? Can you explain using diagrams/EM how structure is related to function? Complete the summary sheet on The Structure and Function of Mitochondria Answer the questions on next slide Exam questions in booklet: Figure 1.2 is an EM of a mitochondria…(2 marks) Figure 3.1 is a diagram representing a mitochondria (4 marks)

Questions Suggest how the structure of a mitochondrion from a skin cell would differ from that of a mitochondrion from the heart muscle tissue Explain the following terms: proton motive force, oxidoreductase enzyme It has been suggested that mitochondria are derived from prokaryotes. What features of their structure support this suggestion?

Questions Suggest how the structure of a mitochondrion from a skin cell would differ from that of a mitochondrion from the heart muscle tissue Mitochondria in a skin cell would be smaller and have fewer and shorter cristae as they are not as metabolically active as heart muscle cells Explain the following terms: proton motive force, oxidoreductase enzyme The force generated by the flow of protons through ATP synthase channels down their concentration gradient. Enzyme that catalyses a reduction reaction that is coupled with an oxidation reaction It has been suggested that mitochondria are derived from prokaryotes. What features of their structure support this suggestion? Their size, which is similar to bacteria, and they have circular DNA