intro to biology & chemistry for vet techs

systems biology

study of organisms and how they interact with their environment/other organisms

homeostasis

the stability of internal conditions

null hypothesis

initial hypothesis

element

a specific substance that cannot be broken down into simpler substances by chemical reactions

how many total elements are there?

118

how many elements are naturally occurring?

94

nucleus

central region of an atom

neutron

no charge particles within nucleus

proton

positively charged particles within nucleus

electrons

negatively charged particles scattered/orbiting around/outside the nucleus

atom

the smallest component of an element that retains all chemical properties of that element

the number of electrons is ____ to the number of protons

equal to

valence electrons

exist in the outer shell, important for chemical reactions

the number of protons is ____ to the atomic number

equal to

atomic mass

(number of protons) + (average number of neutrons)

isotopes

when atoms of the same element have the same number of protons but different numbers of neutrons

ionic bonds

involve 1 atom losing 1 or more electrons and another atom gaining the electrons that were lost by the first atom

ion

atom with a charge

anion

ion w/ negative charge

cation

ion w/ positive charge

covalent bond

when electrons are shared to achieve a full outer shell

molecules

the result of atoms being joined by covalent bonds (smallest unit of a compound)

compound

contain @ least two differeent elements

nonpolar covalent bonds

when two covalently bonded atoms share electrons nearly equally (ex: oxygen molecule O2)

polar covalent bonds

when electrons are shared unequally due to a difference in charge between the atoms, developing a slightly positive/negative charge at each pole of the bond (ex: water molecule H2O)

cohesion

water attracted to itself (ex: surface tension)

adhesion

water attracted to other substances (ex: towel soaking up water)

acid

substance that increases the concentration of hydrogen ions in a solution

base

provides hydroxide ions (or other negatively charged ions) that combine with hydrogen ions, therefore decreasing their concentration in a solution

pH

indicates acidity or alkalinity of a solution