KAMSC Chapter 2

Protons, neutrons, and electrons

three subatomic particles that make up atoms

atom

the smallest unit of matter that cannot be broken down by chemical means

nucleus

Located at the center of an atom, formed from strong forces bonding nuetrons and protons together

electron

• 1 charge, found in the electron cloud

proton

• 1 charge, found in nucleus

neutron

neutral charge, found in nucleus

2

The first orbital in an atom must contain _____ electron(s) to be stable

8

The second and third orbitals in an atom must contain _____ electron(s) to be stable

all orbitals are filled with the maximum amount of electrons possible

an atom is stable when

element

a pure substance made of only one kind of atom

92

How many naturally occurring elements are there?

Isotopes

atoms of the same element that differ in the number of neutrons they contain

atomic number

represents the number of protons in an atom

mass number

the sum of the number of protons and neutrons in an atom

atomic mass

the average mass number of all isotopes of an element

below

the number ______ the element on the periodic table represents the atomic mass

above

the number ______ the element on the periodic table represents the atomic number

chemical bond

a force that joins atoms together

compound

A substance made up of atoms of two or more different elements

covalent, ionic

two main types of chemical bonds

molecule

a group of atoms held together by a covalent bond

more

electrons farther from the nucleus have _____ energy

hydrogen bond

a weak chemical bond between polar molecules

polar molecule

a molecule with an unequal distribution of charge - contains a positive and negative "pole"

polar

water molecules are _______

ionic bond

Formed when one or more electrons are transferred from one atom to another

ion

the result of an ionic bond, an atom or molecule that has gained or lost one or more electrons

cation

A positively charged ion (has lost one or more electrons)

anion

A negatively charged ion (has gained one or more electrons)

van der waals forces

weak attractions that occur when molecules are close together and oppisitely charged regions of nearby molecules are attracted or repelled

70

what percent of your body is made of water

Storage of energy, cohesion, adhesion, high heat capacity, exists naturally in solid, liquid, and gas form, solid form is less dense than liquid form

waters unique properties

cohesion

the attraction between substances of the same kind

adhesion

the attraction between different substances

aqueous solution

a solution in which water is the solvent

solution

a mixture in which one or more substances are evenly distributed in another substance

it is a polar molecule

why is water such a good solvent

polar and ionic

_______ and _____ substances dissolve in water

nonpolar

_______ substances do not dissolve in water

acid

a compound that increases the concentration of hydrogen ions in a solution

base

a compound that reduces the concentration of hydrogen ions in a solution

buffers

weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH

pH scale

indicated the concentration of H+ ions in a solution

7

pure water has a pH of

0-14

the pH scale ranges from

less acidic, more H- ions than H+ ions

high pH (>7) =

more acidic, more H+ ions than H- ions

low pH (<7) =

organic compounds

carbon based, found in living things

4

how many valence electrons does carbon have?

macromolecules

giant molecules, also known as polymers

monomers

atoms or molecules that make up polymers

proteins, lipids, carbohydrates, nucelic acids, ATP

five key classes of organic compounds

carbohydrates

organic compounds made of carbon, hydrogen, and oxygen in the proportions of 1:2:1

carbohydrates

key source of energy for living things

monosaccharides

single sugars, monomers to carbohydrates

disaccharides

double sugars formed when two monosaccharides are joined

polysaccharides

chains of three or more monosaccharides

startch

important energy storage molecules for plants

glycogen

important energy storage molecule for animals

cellulose

important structural molecules for plants

chitin

important structural molecules for animals

glycosidic linkage

bonds monosaccharides together

lipids

nonpolar molecules that are not water soluble

fats, phospholipids, steroids, waxes

four main types of lipids

fats

lipids that store energy

fatty acid tail and glycerol head

structure of fats

saturated

all carbon atoms in the fatty acid are bonded to two hydrogen atoms - usually come in solid form

unsaturated

some carbon atoms in the fatty acid are linked by a double covalent bond - usually come in unsolid form

phospholipids

make up all cell membranes

phospholipid

made up of a glycerol molecule, two fatty acids, and a phosphate group

steroids

communication molecules

hydrophilic

water loving, dissolves in water

hydrophobic

water fearing, does not dissolve in water

protein

large organic molecule made up of amino acids

amino acids

proteins monomers

20

how many different amino acids are there

nucleic acid

long chain of smaller molecules called nucleotides

sugar, base, phosphate group

three parts of a nucleotide

DNA and RNA

two types of nucleic acids

deoxyribonucleic acid

DNA

ribonucleic acid

RNA

DNA

a double strand of nucleotides, stores hereditary information

RNA

a single strand of nucleotides, helps with manufacturing proteins

adenosine triphosphate

ATP

ATP

The main energy currency of cells

adenine, ribose, three phosphate groups

structure of ATP

high energy bonds

what is in between the phosphate groups in ATP

energy is released

When ATP is broken down

energy

the ability to move or change matter

light, heat, chemical, mechanical, and electrical

types of energy

chemical reactions

energy is stored or released by

chemical reaction

a process that changes one set of chemicals into another

spontaneously

chemical reactions that involve releasing energy happen

without an energy source

chemical reactions that involve absorbing energy do not happen

activation energy

the energy that is needed to get a reaction started

catalyst

speeds up chemical reactions

enzyme

a type of protein that acts as a biological catalyst

they lower the activation energy

how do enzymes speed up chemical reactions

active site

a site provided by enzymes where reactants can be brought together and react, reduces energy needed for reaction

reactants

the chemicals that go into a chemical reaction