Chemistry of Cells: Biochemistry Ch. 2, Section 3 Biology Ms. Haut

Carbon Compounds Organic Compounds Contain Carbon Derived from living things Carbon atom has four outer electrons, which can covalently bond with an electron from another atom

Carbon Compounds Carbon can bond with other carbon atoms, gives the ability to form long chains No other element can match the variety of molecules that carbon can form

Macromolecules Formed by process of polymerization Small compounds (monomers) are put together to form larger compounds (polymers)

Major Groups of Biological Molecules Carbohydrates Lipids Proteins Nucleic Acids

Carbohydrates Compounds made up of carbon, hydrogen, and oxygen 1C:2H:1O (C6H12O6) Monomer units are monosaccharides (simple sugars) Disaccharides are made up of 2 simple sugars Glucose ➞ ← Fructose Sucrose

Carbohydrates Polysaccharides —long chains of simple sugars Functions as storehouse of energy Starches —storage form of glucose in plants Glycogen —storage form of glucose in animals

Carbohydrates Polysaccharides —long chains of simple sugars Cellulose —tough fibers give plant strength and rigidity (found in wood and paper)

Lipids (Fats) Large nonpolar molecules, made mostly of carbon and hydrogen Fats Phospholipids Steroids waxes Can be used to store energy Carbon-hydrogen bond store a lot of energy

Fats 3 fatty acids joined to a glycerol molecule

Fats Saturated fatty acid —carbons contain the maximum number of hydrogen (animal fats, butter, lard) Unsaturated fatty acid—carbons have double bonds; chains get kinked (plant oils, some fish oils)

Phospholipids Make up the lipid bilayer of cell membranes

Lipids Waxes—effective hydrophobic coatings (insects, plants, even humans) Fatty acid linked to alcohol

Steroids Ringed structures Serve as chemical messengers in the body (hormones) Cholesterol-functions in the digestion of fats and starting material for hormones

Lipids Lipids store energy efficiently Have many more hydrocarbon (high energy) bonds than carbohydrates

Proteins Monomer units are amino acids 20 different amino acids found in nature—differ in the R group

Proteins Dipeptide—2 amino acids linked together through dehydration (condensation) rxn Amino acids linked by peptide bond—a covalent bond between nitrogen and carbon

Proteins Chains of amino acids are called polypeptides Joined together by covalent bonds called peptide bonds

Proteins Serve various functions Enzymes—speed up chemical rxns Cellular transport Structure—collagen Antibodies—protect body from infection

Protein Structure Primary—sequence of amino acids Secondary—parts of sequence coil or fold due to H-bonds Tertiary—3-D structure due to ionic bonds, disulfide bridges, H-bonds b/w side-chains of amino acids

Protein Structure Quaternary—2 or more polypeptide chains or subunits Enzymes—proteins that act as catalysts (speeding up reactions)

Nucleic Acids Monomer units are nucleotides Deoxyribonucleic acid (DNA) Double stranded helix Carries hereditary information Ribonucleic acid (RNA) Single stranded helix Involved in protein synthesis

Nucleic Acids Polymers made of nucleotides Deoxyribonucleic Acid (DNA)—contains all the information needed to control cell function Ribonucleic Acid (RNA)—plays role in protein synthesis

DNA RNA Double helix Single strand Adenine Cytosine Guanine Thymine Uracil A—T C—G A—U