Respiration

• What is the first reaction in respiration?

  Glycolysis
• Where does glycolysis occur?

  Cytoplasm
• What is the first reactant in glycolysis?

  Glucose
• What is glucose converted to during glycolysis?

  Fructose bisphosphate
• How does glucose turn into fructose bisphosphate during glycolysis?

  Phosphorylation reaction using two ATP molecules per glucose
• What happens to fructose bisphosphate during glycolysis?

  It lyses into two glycerate 3-phosphate molecules
• How does glycerate 3-phosphate turn into pyruvate?


  It is oxidised (looses H) using NAD and an inorganic phosphate is added. Then the two phosphates are removed each releasing sufficient energy to synthesise ADP into ATP
• How many carbons in pyruvate?

  Three
• Explain the structure of fructose bisphosphate?


  Six carbon chain with a phosphate attached to either end
• What happens to pyruvate after it is produced in glyclolysis?

  Enters mitochondria via facilitated diffusion
• What is the overall input into glycolysis?

  1 glucose, 2 ATP, 2 NAD
• What is the overall output of glycolysis?

  2 Pyruvate, 4 ATP, 2 NADH
• What happens after glycolysis?

  The link reaction
• Where does the link reaction take place in the cell?

  Mitochondrial matrix
• What is the starting reactant in the link reaction?

  Pyruvate
• During the link reaction, what is the first thing pyruvate is turned into?

  Acetate
• How does pyruvate become acetate in the link reaction?

  Decarboxlated and oxidised (using NAD)
• What does acetate turn into in the next step of the link reaction?

  Acetyl CoA
• How does acetate turn into acetyl CoA?

  Acetate combines with CoA
• What is the overall input of the link reaction?

  2 Pyruvate, 2 NAD & 2 CoA
• What is the overall output of the link reaction?

  2 Acetyl CoA, 2 NADH, 2 Carbon dioxide
• What stage of respiration comes after the link reaction?

  The Krebs cycle
• Where does the Krebs cycle take place in the cell?

  Mitchondrial matrix
• What is the starting reactant of the Krebs cycle?

  Acetyl CoA
• What is acetyl CoA turned into before entering the Krebs cycle?

  Acetate
• How many carbons in acetate?

  Two
• What does acetate combine with at the start of the Krebs cycle?

  Oxaloacetate
• How many carbons are in a molecule of oxalocetate?

  Four
• What is formed when acetate and oxaloacetate combine at the start of the Krebs cycle?

  Citrate
• What is citrate produced from?

  Acetate and oxaloacetate
• How many carbons are in a molecule of citrate?

  Six
• In the Krebs cycle, how does citrate turn into the 5C compound?

  Decarboxylation means it looses a carbon. It is oxidised by NAD (looses H)
• In the Krebs cycle, how does the 5C compound turn into the 4C compound?

  Decarboxylation means it looses a carbon. It is oxidised by NAD (looses H)
• What happens to the 4C molecule (after it is generated from 5C) in order to turn it back into oxaloacetate?

  It is oxidised twice (looses H) by FAD & NAD coenzymes and synthesises ATP from ADP
• What is the overall input of the Krebs cycle (per original glucose)?

  2 Acetyl CoA, 6 NAD, 2 FAD & 2 ADP
• What is the overall output of the Krebs cycle (per original glucose)?

  4 Carbon dioxide, 6 NADH, 2 FADH & 2 ATP
• What stage of respiration occurs after the Krebs cycle?

  Oxidative phosphorylation
• What are the two key componenet of oxidative phosphorylation?

  Electron transport chain & chemiosmosis
• Where does oxidative phosphorylation take place in the cell?

  Across the inner mitochondrial membrane
• How does the first electron carrier protein get an electron during oxidative phosphorylation?

  NADH or FADH are oxidised to loose a hydrogen ion (proton) and electron