3.3.11

Evaluate the relative contributions of the three energy systems during different types of exercise.

3.3.10

Discuss the characteristics of the three energy systems and their relative contributions during exercise.

Based on the information in the chart:

Evaluate each energy system and their roles during different types of exercise (endurance athlete, baseball player, sprinter), as well as the main nutrient(s) used and the byproducts produced

3.3.9

Describe the production of ATP from glucose and fatty acids by the aerobic system.

In the presence of oxygen, pyruvate is processed by the Krebs cycle, which liberates electrons that are passed through the electron transport chain producing energy (APT).

Fats are also broken down by beta-oxidation that liberates a greater number of electrons thus more ATP. In the presence of oxygen and in extreme cases protein is also utilized.

Acetyl-CoA

3.3.8

Explain the phenomena of oxygen deficit and oxygen debt.

Oxygen deficit – when oxygen need and oxygen supply do not match during the first moments of exercise.

Oxygen debt – (now better known as Excess Post-exercise Oxygen Consumption…. (EPOC)) – During recovery from exercise, oxygen consumption continues at a greater rate than needed at rest.

• O2 consumption remains elevated after exercise:

1. To rebuild ATP and Pcr stores in the cells
2. O₂ is “borrowed” from hemoglobin, especially myogloblin during initial stages of exercise and must be “repaid”

• Oxygen cost to help offset increase body temp following intense exercise

3.3.7

Describe the production of ATP by the lactic acid system.

Also known as anaerobic glycolysis- the breakdown of glucose to pyruvate without the use of oxygen. Pyruvate is then converted into lactic acid, which limits the amount of ATP produced (2 ATP molecules).

3.3.6

Describe the re-synthesis of ATP by the ATP-CP system.

Creatine phosphate (a high energy molecule) is broken down to provide a phosphate molecule for the re-synthesis of ATP that has been utilized during the initial stages of exercise.

3.3.5

Explain the role of ATP in muscle contraction.

                 

The break down of ATP to ADP releasing a phosphate molecule provides energy for muscle contraction.

Phosphorylation of a protein = a conformational change in that protein

3.3.4

Explain how adenosine can gain and lose a phosphate molecule.

• The ATP molecule acts as a chemical 'battery', storing energy when it is not needed, but able to release it instantly when the body requires it.
• ATP works by losing the endmost phosphate group when instructed to do so by an enzyme.
• This reaction releases a lot of energy, which can then be used to build proteins, contract muscles, etc.

• The end product is adenosine diphosphate (ADP), and a phosphate molecule. 
• Additional energy can be extracted by removing a second phosphate group to produce adenosine -monophosphate (AMP).
• When the body is resting and energy is not immediately needed, the reverse reaction takes place and the phosphate group is reattached to the molecule using energy obtained from food.