CARBOHYDRATES

CARBOHYDRATES Made of C, O, H Functions: Monomers = monosaccharides empirical formula: (CH2O)n or CnH2nOn Functions: Quick energy source in all organisms Structural role (i.e. cellulose) Cell-to-cell recognition Monomers = monosaccharides Polymers = polysaccharides

“simple carbohydrates” = SUGARS! “complex carbohydrates” = whole grains, potatoes, beans, etc.

Monosaccharides (monomers) 5 carbon monosaccharides (C5H10O5) Deoxyribose Ribose What do you think these are involved in?

Monosaccharides (monomers) 6 - carbon monosaccharides (C6H12O6) called “hexoses” Examples glucose fructose, galactose Structural isomers = same molecular formula but different arrangement of atoms

Glucose

Fructose

Galactose It may look a lot like glucose, but there are differences. OH

Can you spot the difference? OH Glucose Galactose

Can you spot the difference? OH Glucose Galactose

Making Disaccharides 2 monomers join via _____________, results in a disaccharide. Bonds are called glycosidic bonds. Famous disaccarides include: glucose + glucose = maltose glucose + fructose = sucrose glucose + galactose = lactose

Maltose - A Second Look

3 Important Polysaccharides Glycogen Main sugar storage (in muscles & liver) of animals Polymer of glucose Molecule is highly branched

Main storage form of sugar in plants Polymer of glucose B. Starch Main storage form of sugar in plants Polymer of glucose Doesn’t branch nearly as much as glycogen

Starch – a polysaccharide

C. Cellulose 1. Structural support in plants 2. Long chains 3 C. Cellulose 1. Structural support in plants 2. Long chains 3. Linkage between carbon atoms of adjacent sugar chains is different 4. No mammal can break this bond so is therefore indigestible 5. Most prevalent polysaccharide on Earth 6. Molecule is unbranched

Cellulose vs. Starch Unusual / flipped glycosidic bonds of cellulose

Why Fibre?