AP Bio Unit 1

electronegativity

measure of an atom’s ability to attract electrons

chemical bonds

attraction between 2 atoms resulting from the sharing or transferring of valance electrons

covalent bond

when 2+ atoms share electrons (usually nonmetals)

ionic bond

electrons are transferred between 2 atoms

hydrogen bond

the partially positive H atom in one polar covalent molecule will be attracted to an electronegative atom in another polar covalent molecule

polarity

unequal sharing of electrons in H2O

cohesion

attraction of molecules to other molecules of the same kind (surface tension)

adhesion

clinging of water molecules to different molecules due to polarity (water going up stem)

capillary action

upward movement of water due to cohesion, adhesion, and surface tension (plants nutrition)

high specific heat

resists changes in temperature through H bonds (ocean doesn’t freeze)

evaporative cooling

molecules with the highest kinetic energy leave as gas (stabilizes water temps, sweating)

lower density as solid than liquid

as water solidifies, it expands and becomes less dense due to H bonds

universal solvent

water as dissolving agent in a solution (its polar molecules are attracted to other polar molecules to form H bonds)

carbon

-can form single double or triple covalent bonds via valance electrons

-this can link them into a chain

hydrocarbon

organic molecule only consisting of C and H

hydroxyl group

carbonyl group

carboxyl group

amino group

phosphate group

dehydration reaction

bonds 2 monomers with the loss of H2O

A + B —> AB + H2O

hydrolysis

breaks the bonds in a polymer by adding H2O

AB + H2O —> A + B

carbohydrates

CHO

-energy storage and structure

-monosaccharides, disaccharides, and polysaccharides

- hydroxyl and carbonyl groups

monosaccharides

simple sugars, can serve as building blocks for amino acids or monomers

polysaccharides

polymer with many sugars joined via dehydration ractions

-storage (starch for plants, glycogen for animals)

-structural (cellulose for plants, chitin for animals)

proteins

CHON(S)

-amino acids, peptides, polypeptides (3D folded polypeptides)

-shape determines function

-amino + carboxyl + R group

amino acids

amino group + carboxyl group (20 different ones)

protein structure

nonpolar

hydrophobic

polar/charged/ionic

hydrophilic

polypeptides

many amino acids linked by peptide bonds (each has a unique amino acid sequence and unique ends with N terminus and C terminus)

primary protein structure

linear chain of amino acids, determined via genes, dictate other forms

secondary protein structure

coils and folds due to H bonding within the polypeptide backbone (B pleated bonding with amino acid and a helix with every 4th)

tertiary protein structure

3D folding due to interactions between the side chains of the amino acids, disulfide bridges

quaternary protein structure

arrangement and interaction of multiple folded polypeptide chains into a larger protein complex

nucleic acids

CHONP

-processes hereditary information

-forms are DNA and RNA

-nucleotides —> polynucleotides

-contains nitrogenous base, pentose, and phosphate group

nitrogenous base (pyrimidine)

one ring, 6 atoms, cytosine, thymine in DNA and uracil in RNA

nitrogenous base (purine)

2 rings (one 6 atoms, one 5 atoms), adenine and guanine

5C sugar/pentose

sugar bonded to the base (deoxyribose in DNA, ribose in RNA)

phosphate group

added to the pentose (which is attached to the base) to form a nucleotide

polynucleotide

phosphate groups link adjacent nucleotides through phosphodiester linkage

-directionality (one 5 to 3, one 3 to 5)

sequence of nucleotide bases

-unique for each gene

-dictates amino acid sequence

-dictates primary structure of a protein and 3D structure of a protein

DNA

consists of 2 polynucleotides, forms a double helix, antiparallel strands, held together by H bonds with bases, base pairing (A- T, C-G), OH and H

RNA

single stranded polynucleotide, variable in shape, base pairing (A - U, C- G), OH and OH

Adenine and thymine/adenine and uracil

2 H bonds

cytosine and guanine

3 H bonds

lipids

-CHOP

-glycerol and fatty acids —> no real polymer

-nonpolar hydrophobic

-glycerol (hydroxyl groups) + fatty acids (long C chains with carboxyl group at one end)

-3 fatty acids join to a glycerol via ester linkage

unsaturated fatty acid

contains one or more double bond, missing a H

saturated fatty acid

no double bonds, more H

phospholipids

-major component of cell membranes

-2 fatty acids attached to a glycerol and a phosphate

-assemble as a bilayer with hydrophobic tails and hydrophilic heads

steroids

lipids with 4 fused rings, unique groups attached to the ring determine the type