Respiration

• Gylcolysis is the first stage of both anaerobic and aerobic respiration as it does not use oxygen.
• There are three steps in glycolysis:

  Glucose is phosphorylated to glucose phosphate by ATP.

  Glucose phosphate breaks down into two triose phosphate molecules

  Triose phosphate is oxidised to produce pyruvate producing a net gain of 2xATP and 2xNADH
• 2 ATP is needed to phosphorylate glucose to glucose phosphate but 2 ATP molecules are produced for each pyruvate molecule meaning there is a net gain of 2.
• Pyruvate is oxidised to acetate, reducing NAD to NADH and producing Carbon dioxide and acetate (2C)

  coenzyme A combines with acetate to form acetylcoenzyme A
• What are the products of the link reaction?

  2 x AcetylCoA

  2 x CO2 Released

  2 x NADH
• Acetylcoenzyme A binds to a four carbon molecule to form a six carbon molecule. 2 CO2 molecules are released, an ATP molecule is hydrolysed, 3 NAD and 1 FAD are reduced. This produces four carbon molecule.
• What are the products of one cycle of the calvin cycle?

  3 x NADH

  1 x FADH

  1 x ATP
• In the electron transport chain, electrons released from the break down of NADH to NAD and FADH to FAD pass through electron carrier proteins, releasing energy as they do. This energy is used to pump H+ ions across the inner mitochondrial membrane.

  A hydrogen ion gradient is established across the membrane, and H+ ions move down this membrane by passing through ATP synthase where they are used to produce ATP.

  The electrons from the ETC are accepted by oxygen. H+ ions that have passed through ATP synthase bond with the oxygen that accepted the electrons to form H2O