Cellular respiration ( Catabolic)

Anaerobic Respiration and energy yield

Respiration that does not require oxygen and occurs in the cytoplasm. Low energy yield (2 ATP per glucose).

Aerobic Respiration

Respiration that requires oxygen and occurs in the cytoplasm and mitochondria.

energy yield (30-38 ATP per glucose).

Glycolysis

Glycolysis: splitting of glucose

Location: cytosol/cytoplasm

Reactants: 1 glucose

Products:

• 2 pyruvate

• lactic acid (cramp) in muscle

  • Also transported to the liver by blood to combine with oxygen to form glucose → glycogen through aerobic respiration

ATP yield: net gain of 2 (needs 2 atp but gains 4 atp)

• Oxygen not required

Pyruvate oxidation

→ before entering next stage (precursor)

Pyruvate is mixed with Coenzyme A in the presence of oxygen to form Acetyl CoA → when 1 of the 3 CO2 is removed from pyruvate

• occurs in mitochondrion

• no atp in this process

• need oxygen

Krebs Cycle

Kerb cycle: Carbon atoms in acetyl CoA are released in carbon dioxide

location: outer membrane (matrix)

Reactants: 2 acetyl CoA ( cycles twice)

Products:– 2 CO₂, 3NADH and FADH₂ ( one every cycle)

ATP yield: Net gain of 2 (1 per cycle)

• Oxygen requried

Electron Transport Chain

Location: mitochondria - inner surface

Reactants: NADH and FADH₂ → produced during kerbs and glycolysis

Product: H₂O

ATP yield: net gain of 26-34

oxygen required and used to form water

• produce water

• yield 26-34 ATP.

End Products of Aerobic Respiration

Carbon dioxide and water are produced as end products.

End Product of Anaerobic Respiration

Lactic acid is produced as the end product.

Role of ATP in the Body

ATP serves as an energy source by releasing energy when a phosphate group is removed, allowing the body to perform various functions.

How ATP is used in the body

60% of energy released as heat → body temperature (homeostasis)

40% of energy incorporated into ATP

• Building complex molecules

• Cell division and growth

• Movement of cell organelles

• Movement of whole cell

• Maintaining cell organisation

• Active transport

• Transmission of nerve impluses