Chapter 3: Molecules of Biology

• molecules and compounds that contain carbon - proteins, carbohydrates, lipids, nucleic acids

• molecules that do not contain carbon - exception: CO2

• 20 different monomers of proteins (the polymer) - memorize structure of the backbone of amino acid

• bond between polypeptide chains that is formed through dehydration synthesis (the removal of H2O) • OH of carboxyl group and H of amino group combine together • broken through hydrolysis (addition of H2O)

• enzyme • hormone • channels • structural elements • carriers • messengers

• unique: monosaccharide/a single saccharide (monomer) can be called a carbohydrate • made only of CHO… C:H:O ratio–> 1:2:1 • sugar molecules

• monosaccharide with formula C6H12O6 • differ in way double bonded oxygen is oientated • glucose can form a ring structure

-disaccharide formed from 2 glucose molecules through removal of one water C12H22O11

-disaccharide that is formed when one glucose combines with one fructose in dehydration synthesis C12H22O11

• more than two monosaccharides combined together • glycogen: animals store glucose • starch: plants store glucose • cellulose: forms the plant’s cell walls • differ in way glucose molecules are linked together

• energy storage compounds • components of cell membranes • provide insulation and cushioning

• monomer of lipids are fatty acids and glycerol • carbon atom with two hydrogen atoms bonded to it • hydrocarbon chains are typically 12-24 carbons long and are hydrophobic (nonpolar)

• triglycerides • cholestrol • phospholipids

• 3 fatty acids (hydrocarbon chain with carboxyl group at the end) bonded to a glycerol (alcohol with three carbon atoms) • fat is stored in this form

• 2 fatty acids, one phosphate group, 1 glycerol • polar (hydrophilic) on phosphate side (head), nonpolar on fatty acid end (tail) • form lipid bilayer

• hydrocarbons form rings • found only in animal cells in the cell membrane to maintain and build cell membrane • steroid hormones (hydrophobic) are derived from cholestrol • also found in blood and body tissues • good cholestrol: HDL • bad cholestrol: LDL

• typically found in nucleus of the cell • monomer: nucleotide • polymer: nucleic acid (polynucelotide), ex. are DNA and RNA • nucelotide: backbone (phosphate, sugar), base • nucleic acids are the different strands of DNA • order of the nucleotide changes the strand of DNA • C and G form triple hydrogen bond (more stable) • A and T form double hydrogen bond • A and G are purines (larger molecule) • C and T are pyridimines

• single-strandedness allows for it to assume many different shapes (not restricted by the double helix) • can form base pairs with itself • uracil instead of thymine

-fundamental units of the physical world

-composed of individual atoms combined together

-molecule with only one type of an atom

-molecule with different types of atoms combined in an ionic bond

-large organic molecule

-strings of repeated units