Module 8: Cell Respiration and Photosynthesis (Option C for SL only) 8.1 Cell Respiration

Module 8:Cell Respiration and

Photosynthesis(Option C for SL only)

8.1 Cell Respiration

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.

Word Meaning

Oxidation Electrons lostOxygen gainedHydrogen lost (H+ also called proton)

Reduction Electrons gainedOxygen lostHydrogen gained (H+)

Phosphorylation The addition of a phosphate group

Decarboxylation The removal of a carbon

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

(G3P)

(fructose-1,6-bisphosphate)

Reduction

Substrate level phosphorylation – phosphate added directly onto ADP

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

Label: Cristae, inner membrane, outer member, intermembrane space, matrix, ribosomes

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.

• Pyruvate enters mitochondrion• Enzymes in matrix remove a carbon (decarboxylation) and

hydrogen (oxidation)• Hydrogen is accepted by NAD+ (forms NADH)• The whole process is called oxidative decarboxylation• The product is an acetyl group that reacts with coenzymeA

(CoA)• Acetyl CoA then enters the Krebs Cycle

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.

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

• Occurs in matrix of mitochondrion• Decarboxylation occurs• Oxidation/removal of hydrogen by NAD and FAD• Substrate level phosphorylation

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.

http://highered.mcgraw-hill.com/olc/dl/120071/bio11.swf

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.

• Transfer of hydrogen to inner membrane carriers• Hydrogen is pumped across inner membrane• Creates a concentration gradient• Electrons transferred between carriers• Chemiosmosis• Hydrogen ions passes down concentration gradient through

ATP synthase• Oxygen is the final electron acceptor and this forms water

8.1.5 Explain oxidative phosphorylation in terms of chemiosmosis.

• This involves the movement of protons (H+) to provide energy for the phosphorylation of ADP to form ATP using the electron transport chain (ETC)

• ATP synthase found on the inner mitochondrial membrane uses the H+ gradient to make ATP

• H+ move passively down the concentration gradient back

into the matrix• 1 NADH = 3 ATP• 1 FADH2 = 2 ATP

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

• Cristae increase SA for ETC function• Membranes provides barrier for proton accumulation• Enzymes embedded in membranes in order for ETC and

chemiosmosis to occur.

Location Reactants Products Oxygen required?

Glycolysis

Link Reaction

Krebs Cycle

ETC + Chemiosmosis

Summary Chart (1 glucose)

Task: Try filling the chart out!

Location Reactants Products Oxygen required?

Glycolysis Cytoplasm 1 glucose2 ATP

2 pyruvate2 ATP2 NADH

No

Link Reaction Mitochondrial matrix

2 pyruvate 2 acetyl CoA2 NADH

No (but will occur in the presence of O2)

Krebs Cycle Mitochondrial matrix

2 acetyl CoA 2 ATP6 NADH2 FADH2

4 CO2 (released)

No

ETC + Chemiosmosis

Inner mitochondrial membrane + intermembrane space

6 NADH2 FADH2

3 x 6NADH = 182 x 2FADH2 =422 ATP

Yes

Summary Chart (1 glucose)

ATP used ATP made NADH, FADH2 made

Total ATP

Glycolysis 2 4 2 NADH x 3 = 6 (but 2 ATP are used to transport pyruvate into mitochondria)

8

Link Reaction 0 0 2 NADH x 3 = 6 6Krebs Cycle 0 2 ------------------- 2ETC and chemiosmosis

0 0 6 NADH x 3 =

182 FADH2 x 2= 4

22

Total 38

ATP Count