BIO235 Unit 1 Ch 2

Chemistry

The science of the structure and interactions of matter

matter

anything that occupies space and has mass

mass

the amount of matter in any object (does not change)

Weight

the force of gravity acting on matter (does change)

solid

state of matter with definite shape and volume

liquid

state of matter that's shape takes that of it's container and has definite volume

gas

state of matter that has neither definite shape nor volume

major elements

4 elements that consitiute majority of bodies mass

94

Percentage of body mass that major elements compose

Oxygen, Carbon, Hydrogen, Nitrogen

The 4 major elements of the body

lesser elements

8 elements that consitiute a small but significant portion of the bodies mass

3.6

Percentage of body mass that lesser elements compose

Calcium, Phosphorous, Potassium, Sulfur, Sodium, Chlorine, Magnessium, Iron

The 8 lesser elements of the body

trace elements

additional 14 elements that are present in tiny amounts in the body

0.40%

Percentage of the body mass that trace elements compose

Iodine

Necessary trace element for the production of thyroid hormones

Oxygen

Part of water and many organic (carbon-containing) molecules; used to generate ATP, a molecule used by cells to temporarily store chemical energy.

65

oxygen is what percent of the total body mass

Carbon

Forms backbone chains and rings of all organic molecules: carbohydrates, lipids (fats), proteins, and nucleic acids (DNA and RNA).

18.5

Carbon is what percent of the total body mass

Hydrogen

Constituent of water and most organic molecules; ionized form makes body fluids more acidic.

9.5

Hydrogen is what percent of the total body mass

Nitrogen

Component of all proteins and nucleic acids.

3.2

Nitrogen is what percent of the total body mass

Calcium

Contributes to hardness of bones and teeth; ionized form needed for blood clotting, release of some hormones, contraction of muscle, and many other processes.

1.5

Calcium is what percent of the total body mass

Phosphorous

Component of nucleic acids and ATP; required for normal bone and tooth structure.

1

Phosphorous is what percent of the total body mass

Potassium

Ionized form is the most plentiful cation in the ICF; needed for generting action potentials

0.35

Potassium is what percent of the total body mass

Atoms

smallest units of matter that retain propeties and characterstics of that element

Proton

positively charged subatomic particle

Neutron

uncharged subatomic particle

nucleus

made of Protons and neutrons

electron

negatively charged subatomic particle

electron shells

regions around the nucleus where groups of electrons are most likely to be

protons

the number of ________ determines the anatomic number

neutrons + protons

determines mass number

Isotopes

atoms of the same element with different numbers of neutrons and therefore different mass numbers

Radioactive isotopes

isotopes that are unstable and exhibit nuclei decay where energy is released and subatomic particals transform, changing the element

Half life

time it takes for half the radioactive isotopes in a sample to decay

Dalton

standard unit for measuring the mass of atoms and their subatomic particals

atomic mass number

Dalton is also known as

Atomic mass

average mass of all naturally occuring isotopes of an element

Ion

atom with positive or negative charge

ionization

process of giving or taking electrons resulting in charged atom

molecule

when 2+ atoms share electrons

compound

substance with atoms from 2+ compounds

free radical

atom or group of atoms with unpaired electron, extremely reactive (potentially destructive)

Chemical bonds

forces that hold together the atoms of a molecule or comound

valence shell

outermost electron shell; determines likelihood of bond formation

Octet rule

a chemical principle stating that main-group elements tend to bond in a way that gives them eight electrons in their outermost valence shell

Ionic Bond

The force of attraction that holds together ions with opposite charges

cation

positively charged ion

anion

negatively charged ion

electrolyte

inonic compound that breaks apart into its ions in solution

Covalent bond

formed when 2+ atoms share electrons, most common bond in the body

stronger the bond

in a covalent bond the more electrons shared between atoms the __________

Single covalent bond

when 2 atoms share a single electron pair

double covalent bond

when 2 atoms share two pairs of electrons

triple covalent bond

when 2 atoms share three pairs of electrons

nonpolar

covalent bond where sharing of electrons between atoms is equal

polar

covalent bond where sharing of electrons between atoms is unequal

electronegativity

the power to attract electrons to itself

oxygen

in H2O this is the more electronegative molecule

Hydrogen Bonds

when hydrogen atom with partial positive charge attracts the partial negative charge of neighbouring electronegative atoms

Weak (and can't form molecules)

Hydrogen bonds differ from other bonds because they are ____

proteins, nucleic acids

Hydrogen bonds are important for

cohesion, high surface tension

Hydrogen bonds link neighbouring molecules which creates ______, and ________

Chemical Reactions

when new bonds form or old ones break between atoms

Reactant

starting substances of reaction

Products

ending substances of reaction

Metabolism

All chemical reactions occuring in the body

Energy

capacity to do work

Potential Energy

energy stored by matter due to its position

Kinetic Energy

energy associated w. matter in motion

Chemical energy

a form of potential energy stored in the bonds of compounds and molecules

Law of Conservation of Energy

Energy cannot be created or destroyed just converted from 1 form to another

Exergonic Reactions

Reactions that release energy

Endergonic Reactions

Reactions that absorb energy

Activation Energy

initial energy required to start a reaction

Concentration, Temperature

Increased _________ and _________ increase chances of collision increasing chance of reaction

Catalysts

speed up chemical reactions by decreasing activation energy without being changed in the process

Enzymes

typically make catalysts

Anabolism

synthesis reactions (typically endergonic)

Catbolism

decomposition reactions (typically exergonic)

Exchange reactions

when a reaction has synthesis and decomposition components

Reversible Reactions

when a reactions' products can revert back to the original reactants

Oxidation

Loss of electrons (exergonic)

Reduction

Gain of electrons (endergonic)

Oxidation-Reduction Reactions

reactions that are always parallel where one reactant is being oxidized and the other is being reduced

Inorganic Compounds

lack carbon and are structurally simple

Organic Compounds

contain carbon, usually contain hydrogen and always have covelent bonds

Water

the most imortant and abundant inorganic compounds in all living systems

Solute + Solvent

A Solution =

Hydrophilic

Solutes that are charged or contain polar covalent bonds

Hydrophobic

Solutes that are not water soluble (nonpolar, uncharged)

Hydrolysis

decomposition reactions resulting from the addition of a water molecule

Dehydration Synthesis reaction

When 2 smaller molecules join to fom one larger molecule when a water molecule is removed

Mixture

combination of elements or compounds that are physically blended together but not bound by any chemical bonds