Unit 1 Biology - into to biochemistry and water structures and functions

Proton (mass, charge, location)

mass - one atomic unit (AU)

charge - positive

location of subatomic particles - inside the nucleus

Neutron (mass, charge, location)

mass - one atomic unit (AU) (a tiny bit more)

charge - neutral

location of subatomic particles - inside the nucleus

Electron (mass, charge, location)

mass - zero atomic units (AU)

charge - negative

location of subatomic particles - outside the nucleus

atom

smallest piece of an element

isotope

different forms of the same atom that vary only in the # of neutrons they posses

ion

an atom or molecule that has a net electrical charge because it has lost one or more electrons

cation

positively charged ion, formed when an atom loses one or more electrons, has more protons than electrons

anion

negatively charged ion, formed when an atom gains one or more electrons, has more electrons than protons

ionic bonds

chemical connection formed between ions with opposite charges, through the attraction of the opposite charges

non polar covalent bond

form between two atoms of the same element or between elements that share electrons equally, no positive or negative charge

polar covalent bond

two atoms unequally share electrons, one has higher electronegativity than other which gets a partial negative charge, and the weaker gets a partially positive charge, shared electrons are more attracted to the stronger atom

label parts of the polar structure of water

oxygen = slightly negative

hydrogen = slightly positive

what is hydrogen bonding

electrostatic attraction between the partial positive hydrogen atom of one water molecule and the partial negative oxygen atom of another

weak bonds - very easily broken

why does hydrogen bonding occur

hydrogen from one water molecule forms bond with oxygen of another molecule of water because of their opposite charges

hydrogen bonding - surface tension

molecules inside are pulled equally

surface molecules have no water above them so they bond instead with adjacent molecules and form stronger lateral and downwards bonds

unequal pull squeezes the surface layer together, resisting outside pressure and breakage

hydrogen bonding - density of water

make liquid water denser than solid ice

liquid water - molecules move fast, hydrogen bonds constantly break, packs molecules close together

solid ice - hydrogen bonds form a hexagonal lattice, spaces molecules farther apart than liquid state

hydrogen bonding - heat capacity

water can absorb heat without changing temperature or changing into a gas

heat energy is first consumed to break hydrogen bonds holding molecules together apart instead of raising the temperature of the molecules

hydrogen bonding - ability to dissolve substances

water molecules form protective hydration shells around polar and ionic solutes, water molecules pull other molecules apart which keeps them evenly dispersed in solution

hydrogen bonding - cohesion

definition: attraction between like molecules

hydrogen bonding meaning water is polar

causes partially positive and negative water molecules to stick to each other

hydrogen bonding - adhesion

definition: attraction between unlike molecules

water is polar because of hydrogen bonding, so it sticks to other polar or charged surfaces