Biological Chemistry

Thursday February 16th, 2006

http://charlescurtis.ca

Summary

CarbohydratesLipidsProteinsDenaturationNucleic Acids

Carbohydrates

Molecules which contain carbon, hydrogen and oxygen

Used as a source of energy for plants and animals

Monosaccharides

Simplest carbohydrateContains only one unit of a sugar

moleculeMost commonly contain six carbons

Disaccharides

Contains two sugarsMost common is sucrose (table sugar)

Polysaccharides (Complex Carbohydrates)

Insoluble in waterExamples include:

RiceWheat flourCornstarchPotatoesPasta

Cellulose

Different type of bond between monosaccharides

Humans can not digest

Chitin

Modified form of celluloseFound in hard exterior skeletons of

insects and crustaceans

Lipids

Like carbohydrates contain carbon, hydrogen and oxygen

Contain less oxygen then carbohydratesMore dominated by C-H, and C-C bonds

Triglycerides

Contains glycerol and three fatty acidsGlycerol section is always the same,

therefore it is the change in fatty acids that make up different triglycerides

What was different?

Saturated fatUnsaturated fat

Review of Carbon BondingForms four bondsBond can be single, double or tripleSingle bonds give overall straight fat structureDouble bonds produce a kink

Fats vs Oils

Waxes and Phospholipids

See page 30 of text bookWaxes

Contain carbon and hydrogenCompletely non-polar

PhospholipidsSimilar to triglyceride but with phosphate

bases and with only two fatty acids

Steroids

Made up of four carbon ringsExamples

Sex hormones: testosterone and estradiolcholesterol

Proteins

Are built from 20 amino acids8 are considered essential because the

body can not synthesis them from other molecules

The Peptide Bond

Polypeptide

Enzymes and Catalysts

Enzymes are proteins, which increase the rate of reaction. They allow reaction to occur at room temperature.

Enzymes and chemical, which speeds up the rate of a reaction are called catalysts.

Denaturation

Proteins will loose their shape when heated.

See page 32 of text – Figure 19a/bMay or may not be reversibleCan anyone give me an example,

possible one from breakfast?

Nucleic Acids

Contains three parts:A five carbon sugar (ribose or deoxyribose)

Ribose = RNADeoxyribose = DNA

A phosphate groupNitrogen containing organic group.

Adenine (A)Guanine (G)Thymine (T)Cytosine C)

Nucleotide

DNAComposed of two nucleotide strandsForms double helixContains genetic information, which is

passed from one generation to the nextRNA

Composed of a single nucleotideForms single helix

Please Read pages 33 and 34 for more information on Nucleic acid.

DNA – Double Helix

Homework

p35 Questions # 8-14