Sources of Energy
Higher Human Biology
Lesson Aims
• To compare the differences between
mono-, di- and poly-saccharides
• To examine the structure of lipids and
their various roles in cells and organisms
• To study protein degradation and their
use as an alternative respiratory
substrate
Monosaccharides
• Made up of six-sided unit
• Described as reducing sugars
Disaccharides
• Made of two monosaccharides joined
together
Polysaccharides
• A polysaccharide is a carbohydrate
composed of many monosaccharide
molecules joined together.
• ALL CARBOHYDRATES ARE RICH
SOURCES OF ENERGY
Lipids
Includes fats, oils, phospholipids and
steroids.
Contain C, H and O.
Triglyceride (Simple lipid)
Phospholipids
Steroids
Roles of Lipids
•
•
•
•
•
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Energy store
Thermal and nerve insulation
Fat pads
Vitamin transport
Hormones
Major components of the plasma
membrane
Proteins
• Proteins broken down into amino acids.
• Excess amino acids cannot be stored in the
body.
• They are deaminated into urea and organic
compounds.
• These organic acids enter the respiratory
pathway to produce some ATP
Marathon Running
• In the first few minutes the body uses
glucose from muscle glycogen
• Blood glucose mainly from liver glycogen
is used for the next 30 minutes
• As glucose supplies decrease fatty acids
become the energy supply
The Facts You Need To Know
• page 3
• from “carbohydrates may be ….”
• to “fat pads beneath the skin…”