BIO CH 4/5

Carbon Skeleton

carbon atoms linked together in long chains that form the skeletal framework for organic molecules, vary in length/shape

Carbon atom

atomic \# of 6, central point from which the molecule branches off, determines an organic molecules 3D shape which may affect molecular function

Isomers

Compounds with the same molecular formula but with different structures therefore have different properties

structural isomers

isomers that differ in the covalent arrangement of their atoms (location of double bonds differ)

geometric isomers (cis-trans)

isomers which share the same covalent partnerships, but differ in their spatial arrangement

Enantiomers

isomers that are mirror images of each other

Functional groups

small groups of atoms frequently bonded to the carbon skeleton of organic molecules

Hydroxyl group

H bonded to an O

Carbonyl group

C double bonded to O

Carboxyl

C double bonded and single bonded to an O

Amino group

N bonded 2 H's and to carbon skeleton

sulfhydryl group

S bonded to H

Phosphate group

P bonded to 4 O’s

Methyl group

CH3 bonded to a carbon

Four classes of macromolecules

carbohydrates, proteins, lipids, nucleic acids

dehydration reactions

polymerization reactions where monomers are linked, removing a water molecule for each linkage

hydrolosis reaction

breaks bonds between monomers by the addition of water

glycosidic linkage

covalent bond formed by a dehydration reaction between two monomers

monosaccharides

simple sugars, major nutrients for cells, glucose most commonly

Polysaccharides

macromolecules that are polymers of monomers

starch and glycogen

energy storage polysaccharides

Lipids

organic compounds that are insoluble in water but will dissolve in nonpolar solvents (ether chloroform benzene)

Fat

composed of glycerol, fatty acid, ester linkage

Ester linkage

bond formed between (COH) and (OH)

Fats are hydrophobic

C-H bonds are nonpolar therefore fatty acid chain is hydrophobic

Functions of fat

energy storage, cushion vital organs, insulate against heat loss

saturated fatty acids

no double bonds between carbons, maximum number of hydrogens, solid at room temp, most animal fat

unsaturated fatty acids

one or more double bonds, tail kinks at double bonds, liquid at room temp, most plant fats

phospholipids

glycerol + 2 fatty acids + 1 phosphate group; makes up membrane bilayers of cells; hydrophobic interiors and hydrophillic exteriors

polypeptide chains

polymers of amino acids that are arranged in a linear sequence and linked by peptide bond

Amino acids

building blocks of proteins asymmetric carbon called the alpha carbon covalently bonded to hydrogen, carboxyl, amino, R group

Amino acids are linked by

peptide bonds

Protein confirmation

3D shape of a protein important for both structure and function, enables a protein to bind specifically to another molecule, consequence of the linear sequence of amino acids

primary level of protein confirmation

primary structure: linear sequence of amino acids, determined by genes!, small changes can have large effects

Nucleic acids

DNA and RNA

DNA

makes up genes that contain instructions for protein synthesis

RNA

functions in the actual synthesis of proteins coded in RNA, 3 types: mRNA, tRNA, rRNA

Basic structure of nucleotides

nitrogenous base, phosphate group, sugar