KIN 223 Ch.2

neutrons

mass- 1 amu

no charge

proton

mass- 1 amu

postive charge

electrons

mass- 1/800th amu, almost nothing

negative charge

isotopes

different atoms of the same element

different number of neutrons

radioisotopes

contain excess neutrons, so unstable

neutrons try to leave

physical half-life

The time for 50% of radioisotope to become stable

biological half-life

The time required for half of the radioactive material from a test to be eliminated from the body

octet rule

elements tend to lose, gain, or share electrons to obtain complete outer shell

chemical compound

sable association between 2 or more elements combined in a fixed ratio

ions

atoms w/ postive or negative charge

produced from loss or gain of one or more electrons

Cations

lose electrons, positive charge

Anions

gain electrons, negative charge

ionic bond

the attraction between oppositely charged ions

cations and anions bond

form salt

covalent bond

electrons shared between atoms

occurs when both atoms require electrons

molecular formula

indicates number and type of atoms

structural formula

shows the arrangement of atoms

isomers

same number and type of elements but arranged differently

single covalent bond

1 pair of electrons shared

double covalent bond

2 pairs of electrons shared

triple covalent bond

3 pairs of electrons shared

Electronegativity

relative attraction of each atom for electrons

non polar covalent bond

equal shared electrons

polar covalent bond

unequally shared electrons

electronegativity increases from

left to right, bottom to top

amphipathic molecules

Large molecules with both polar and nonpolar regions

Intermolecular attractions

Weak chemical attractions between molecules

important for shape of complex molecules

hydrogen bond

forms between polar molecules

attraction between partially positive hydrogen atom & partially negative atom

water transport

substances dissolve in it and can be transported

water lubricates

decreases friction between body structures

water cushions

absorbs sudden force of body movements

water excretes wastes

unwanted substances dissolve in water are easily eliminated

cohesion

Attraction between molecules of the same substance (water to water)

surface tension

inward pulling of cohesive forces at the surface of water

adhesion

An attraction between water molecules of different substances

temperature

measure of kinetic energy of molecules

specific heat

amount of energy required to insure temperature of 1 gram of substance by 1 degree celsius

heat of vaporization

The heat required for the release of molecules from a liquid phase into a gaseous phase for 1 gram of a substance

water is the

universal solvent

solutes

substances that dissolve in water

Hydrophilic

water-loving

forms a hydration shell

some substances dissolve but remain intact

substances dissolve and dissociate

Hydrophobic

water-fearing

Hydrophobic exclusion

cohesive water molecules "force out" nonpolar molecules

hydrophobic interactions

excluded molecules

Phospholipids

polar heads and non polar tails

acids

proton donor

increases H+ concentration

more dissociation of H+ w/ stronger acids

less dissociation of H+ w/ weaker acids

Base

proton acceptor

decreases H+ concentration

more absorption of H+ w/ stronger bases

less absorption of H+ w/ weaker bases

pH

measure of H+

As H+ concentration increases,

pH decreases

as H+ concentration decreases

pH increases

neutralization

when acidic or basic solution is returned to neutral

acids neutralized by adding base

base neutralized by adding acid

buffers

help prevent pH changes if excess acid or base is added

accepts H+ from excess acid

donate H+ to neutralize base

blood pH

7.35-7.45

mixtures

formed from combining two or more substances

substances mixed are not chemically changed

substances can be separated

suspension

material larger on size mixed w/ water

does not remain mixed unless in motion

appears cloudy or opaque; scatters light

colloid

smaller particles than a suspension but larger than in the solution

remains mixed when not in motion

solution

A homogeneous mixture of materials smaller than 1 nm

dissolves in water

does not settle if solution not it motion

emulsion

water and non polar liquid substance

does not mix unless shaken

mass/volume

mass of solute per volume of solution

mass/volume percent

grams of solute per 100mL solution

molarity

moles of solute/L of solution

alters w/ changed in temperature

easily measured

molality

moles of solute/kg of solvent

does not alter w/ changes in temperature

slightly more accurate

osmoses

unit of measurement of the number of particles in a solution

reflect if substance dissolves or dissolves & dissociates

osmolarity

number of particles in 1 L solution

easier to measure

osmolality

number of particles in 1 kg of water

more accurate

molar mass

number of units of each element x average atomic mass, + totals

biological macromolecules

large organic molecules synthesized by the body

always contain carbon, hydrogen, and oxygen

some may also have nitrogen, phosphorus, or sulfur

hydrocarbons

contains only carbon and hydrogen

polymers

molecules made of monomers

dehydration synthesis

one subunit looses an -H

other subunit loses an -OH

new covalent bond formed and water produced

Hydrolysis

breakdown of a compound by adding water

\-H added to one subunit

\-OH added to another subunit

lipids

diverse group of fatty, water insolvable molecules

store energy, cellular membrane components

triglycerides

from from glycerol & 3 fatty acids

saturated fatty acid

lack double bond

unsaturated fatty acid

one double bond

polyunsaturated fatty acid

two or more double bonds

Lipogenesis

formation of triglycerides when conditions of excess nutrients exist

Lipolysis

breakdown of triglycerides when nutrients are needed

Phospholipids

amphipathic molecules, hydrophobic tail and hydrophilic head

steroid

composed of hydrocarbons arranged in multilink structure

Eicosanoids

modified 20 carbon fatty acids

local signaling molecules

inflammatory response

Carbohydrates

-H and -OH are usually attached to every carbon

Monosaccharides

Single sugar molecules

Disaccharide

formed from 2 monosaccharides

Polysaccharides

Formed from many monosaccharides.

glucose

6 carbon sugar

most common monosaccharide

primary nutrient supplying energy

concentration must be carefully maintained

glycogen

storage from excess glucose

glucogenesis

formation of glucose

Glycogenolysis

breakdown of glycogen

Glyconeogenesis

formation of glucose from non carb sources

hexose monosaccharide

glucose isomers

5 carbon monosaccharides

pentose sugar

ribose and deoxyribose

disaccharides

2 simple sugars bonded together

sucrose, lactose, maltose

nucleic acids

store and transfer genetic information

nucleic acids linked through

phosphodiester bonds

Nucleotide monomer

sugar, phosphate group, nitrogenous base

Pyrimidines

single ring bases

cytosine, thymine, uracil (RNA)

purines

double ring bases

adenine and guanine

Adenosine Triphosphate (ATP)

composed of nitrogenous base adenine, ribose sugar, and 3 phosphate group

release energy when broken

proteins

Catalyst, as in defense, aid in transport, structural support, cause movement, perform regulation, provide storage

amino acids linked by

peptide bonds

N-terminal end

has free amine group