Energy Systems

Topic 3.3

Labels for an animal cell

• Rough endoplasmic reticulum

• nucleus

• ribosomes

• golgi apparatus

• mitochondria

Labels for the mitochondria

• Inner matrix/ membrane

• Outer smooth surface

• Cristae

Cell respiration

The controlled release of energy in the form of ATP from organic compound cells

How does adenosine gain/lose a phosphate molecule

ATP is broken down by ATPase, and energy is created as a bond is broken.

The phosphate is gained back through the resynthesis of ATP

ATP in muscle contraction

ATP is broken down to release energy, which then powers muscle contraction

How can ATP be resynthesized?

1. Phosphocreatine System

2. Lactic Acid System

3. Aerobic System

ATP-PC system

• Anaerobic reaction in cytoplasm of muscle cells

• Produces 1 ATP, but is resynthesized very quickly

• e.g. 50m sprint

Lactic Acid System (Anaerobic Glycolysis)

• The breakdown of glucose into ATP in the cytoplasm of muscle cells

• Glycogen is broken down via glycogenesis into glucose, which produces 2 ATP,

• Glucose is then broken down into pyruvic acid, which creates lactic acid due to lack of oxygen

Aerobic System (Krebs Cycle)

• Occurs in the matrix and cristae of the mitochondria

• Produces 36-38 ATPs, but is resynthesized slowly

• Glucose is broken down into pyruvate, since O2 is present, the pyruvate is broken down into acetyl COA