sbi4u - biochemistry macromolecules 1 carbohydrates

SBI4U - Biochemistry

Macromolecules 1

Carbohydrates

Macromolecules

• macromolecules are large molecules that are often composed of repeating sub-units

• some of the biologically important macromolecules are:– carbohydrates -lipids– proteins -nucleic acids

Carbohydrates

• carbohydrates are the most important energy source

• animals cannot synthesize carbohydrates; they must be consumed in plant material

Monosaccharides

• single sugars in straight chain or ring form

• C:H:O usually in 1:2:1 ratio (glucose is C6H12O6)

• examples: fructose, galactose, ribose, deoxyribose

Monosaccharides

• some monosaccharides are isomers, e.g., glucose, fructose, and galactose

Glucose Isomers

Disaccharides

• made from 2 single sugars

• examples: sucrose, maltose, lactose

Dehydration Synthesis

• disaccharides are formed by a dehydration synthesis (condensation) reaction

• See animation: http://www.youtube.com/watch?v=UyDnnD3fMaU

Dehydration Synthesis

Hydrolysis Reaction

Find the sugars…

“Healthy” Clif bars continued…

Polysaccharides

• oligosaccharides are shorter-chain sugars with 3-10 single sugars

• longer chain carbohydrates are called polysaccharides

• examples: starch, cellulose, glycogen, chitin

Polysaccharides

Low-Carb Diets

Low-Carb Diets

• Names of popular low-carb-diets?

• What kinds of foods are you allowed/not allowed to eat?

• What are the benefits of the diet?

• What are possible risks of the diet?