anatomy lec chp 2 pt 1

ion

charged particle with unequal number of protons and electrons

formation of ions

gaining ainons or losing electrons

salts

neutral compounds of cations and anions, dissociate in water into ions and act as electrolytes

electrolytes

ionize in water and form solutions

function of electrolytes?

chemical reactivity, osmotic effects, electrical excitability of nerves and muscle

free radicals

unstable, highly reactive particles, with unusual number of electrons

how are free radicals produced?

metabolic reactions, radiation, chemicals

free radicals

trigger reactions that destroy molecules, cause cancer, death of heart tissue and aging

atoms combine to

form molecules

molecule

particle composed of two or more atoms by chemical bond

compound

molecule composed of 2 or more different elements

antioxidants

neutralize free radicals

valence electrons

determine how an atom interacts with other atoms and if it will form bonds

ionic bonds

transfer of electrons

determines an atoms identity and atomic number

protons

determines mass number

protons and neutrons

covalent bond

strongest bond, form when two or more atoms share electrons

nonpolar covalent bond

2 atoms with similiar electronegativity pull with eequal force (CO2)

polar covalent bond

atoms with different electronegativity result in unequal sharing of electrons (H2O)

high electronegativity in polar bonds?

becomes partially negative and pulls electrons close

low electronegativity in polar bonds?

becomes partially positive, pulls electrons towards another atom

hydrogen bond

weak attraction between a slightly positive hydrogen atom slightly negative oxygen or nitrogen in another atom

function of hydrogen bonds

DNA/protein structure and water properties

van der waals forces

weak, temporary attractions between neutral atoms (important for protein folding)

hydrophilic

substances dissolve in water, polarized or charged

hydrophobic

substances do not dissolve in water, nonpolar or neutral

in order to be soluble in water

molecules must be polarized or charged

adhesion

different substances clings to another

cohesion

molecules of the same substance to cling to eachother

thermal stability

amount of heat needed to raise temp of 1g of a substance by 1 cal

water stabilizes

internal temp, hydrogen bonds resist, temp increases by inhibiting molecular motion

solution

made of solute mixed with water called the solvent, transparent, do not seperate

solute can be

gas, solid, or liquid

colloids

mixture of protein and water, larger solutes, scatter light, do not seperate

example of colloid

plasma proteins in blood plasma

suspension

large particles, cloudy, separate on standing

example of suspension

blood cells in plasma

acid

proton donor, releases ions in water, increase H+ concentration

base

proton acceptor, changes ions in water, reduces H+ concentration

neutral

pH of 7

acidic

pH of less than 7

basic

pH greater than 7

buffer

chemical solutions that resist changes in pH