Energy Systems

I will be able to explain how my body converts food into a usable form of energy for my cells.

Goal:

How does the human body generate energy?

Carbohydrates Proteins Fats

Generating Energy

Carbohydrates

Glucose

• Among the most common organic compounds on earth.

· Digestion breaks down carbohydrates into glucose.

· Glucose is stored in the liver and skeletal muscles in the form of glycogen.

Metabolic pathways convert the chemical potential energy in foods we eat into ATP.

ATP fuels cellular processes in our bodies.

ADP + P + Energy → ATP

ATP video

Adenosine triphosphate (ATP)

Anaerobic process that occurs in the cytoplasm of cells.

First of the two anaerobic energy pathways. Makes enough ATP to sustain intense

activity for about 15 seconds. System involves breaking a phosphate

group off of phosphocreatine (PC) molecule and adding it to ADP creating ATP.

PC + ADP → ATP + creatine (Speed Skating Video – Men Team Pursuit)

Metabolic Pathways Pathway 1: ATP-PC System

Allows athletes to participate in a high level of performance for an additional 1-3 minutes.

Anaerobic process that occurs in the cytoplasm.

Products of this reaction include ATP and a molecule called pyruvate.

Pyruvate then moves on to the next pathway which is aerobic.

Pathway 2: Glycolysis

Pathway Overview Video

In the absence of sufficient oxygen, pyruvate is converted into lactic acid.

Lactic acid builds up in the muscle fibres and causes pain and reduces movement.

Lactic Acid

Read Chapter 5 (pgs 81 – 84)

1. List the three key energy nutrients. 2. What is the role of carbohydrates as an

energy source?3. Why is ATP essential for life?4. Compare anaerobic and aerobic systems.5. List the type of activities that would use the

ATP-PC system and Glycolysis.

CHECK H/W

Work: