ap bio summer test

organic molecules

biological molecules that contain carbon and hydrogen

atomic number

amount of protons

covalent bond

a pair of electrons are share between two atoms

electronegativity

an atoms ‘greed’ for electrons. higher electronegativity —> more drawn to electrons

polar covalent bond

electrons shared unequally between 2 atoms

nonpolar covalent bond

covalent bond where electrons are shared equally (i.e. gassses; O2, H2, N2)

ionic bond

chemical bond where 2 ions with opposite electrical charges associate with each other due to differences in charges.

often a large difference in electronegativity; atom with larger electronegativity steals electrons from the one with less

formed between a metal and nonmetal; one becomes pos other becomes neg

polymers

long chains build from monomers

monomers

small repeating subunits

proteins

speed up chemical reactions

produce structural support for the cell

amino acids

subunits that make up proteins

folds / structure determines the function

nucleic acids

encoding & transmitting genetic information. 2 types

deoxyribonjucleic acid —> dna

ribonucleic acid —> rna

long polymers made of nucleotides

carbohydrates

sugars with energy stored in the chemical bonds; when bonds are broken energy is released

lipids

fats ; organic molecules that are hydrophobic

hydrogen bond

interaction between hydrogen atom w/ a slight pos charge and electronegative atom of another molecule (opposites attract)

cohesion

water’s ability / tendency to stick to itself

a result of hydrogen bonding

creates high surface tension (why leafs float on top of water instead of sinking)

adhesion

tendancy of water to stick to things other than itself

surface tension

measure of the difficulty of breaking the bonds on the surface of water

specific heat

amount of heat required per unit of mass of a substance to raise the temperature by one degree celcius

hydrogen bonds cause water to have a high specific heat

heat capacity

amount of heat required to convert 1g of a liquid into a gas without changing the temp

• why sweating and the evaporation of sweat from your body have a large cooling effect

acids & bases

acids —> donate H+ to solutions

bases —> accept H+ and remove them from solutions (NaOH)

pH

measure of the concentration of H+ atoms

pH = -log[H+]

dehydration synthesis reaction

a water molecule is removed as a covalent bond is formed

• used when building larger molecules from smaller solutions

• forms covalent bonds

hydrolysis reactions

break covalent bonds by using water as a solevent (adding H2O)

• one of the products of the reaction gains a H+ atom while the other gains a OH group

functional groups

groups of 1 or more atoms of particular chemical properties regardless of what they are attached to

• hydroxl -OH

  • polar b/c O is electroneg. hydrophilic

  • comonly found in carbohydrates, proteins, nucleic acids

• carboxyl -COOH

  • polar, negative charge @ pH of cell, hydrophobic

  • commonly found in fatty acids, amino acids, proteins

RNA & DNA sugars

ribose - 5 carbon sugar, component of nucleic acid and rna

deoxyribose - 5 carbon sugar, component of nucleic acid and dna

most carbohydrates contain only C, H, O and possibly N, P

difference between the two sugars is ribose has an OH group on one of the carbons while deoxyribose only had H

disaccharide

2 simple sugars linked by a covalent bond

i.e. sucrose C12H22O12

glycosidic bonds

covalent bonds that connect monosaccharides

formed by dehydration synthesis (h2o produced as a product)

plasma cell membrane

made up of a double layer of phospholipids

proteins inside

triglycerol

lipid used for energy storage

made of glycerol joined with three fatty acids

glycerol

three carbon molecule with a hydroxl group on each carbon

fatty acid

chain of carbon atoms attached to carboxyl group at the end (-COOH)

• can be acidic, nonpolar, polar, basic

• joined by dehydration synthesis

• constant motion of e- that leads to different + / - charge regions

saturated fatty acid

contains no double bonds

max amount of hydrogen atoms attached to each central carbon

unsaturated fatty acid

contains a C--C double bond

van der waals forces

interaction of temporary polarized molecules due to charges

only in effect when molecules are close to each other

• helps to stabalize molecules

weak attractions due to opposite forces (s+ / s-)

steroids

second type of lipid

cholesterol —> found in animal products, 20 carbon atoms that form 4 rings

starting molecule for building hormones

phospholipids

glycerol backbone attached to fatty acids

make up most cell membranes

have both hydrophobic and hydrophilic regions

• head is hydrophilic, tail is hydrophobic