Bio Exam 1 Vocab

Chemical Reactions

when a bond is made or broken. These are reversible-meaning the reaction can proceed in the forward or reverse direction

Single Bond

the sharing of one pair of valence electrons

Potential Energy

is the energy that matter possesses because of it’s location or structure

Valence

the atoms bonding capacity (ie how many electrons available for bonding)

Emergent Properties

characteristics specific to an element

Atom

the smallest unit of matter that still retains the properties of an element

Neutrons

a subatomic particle with no charge that is located in the atomic nucleus

Electrons

a subatomic particle with a negative charge located in electron shells also called the electron cloud

Products

the resulting molecules from a chemical reaction

Compound

a substance consisting of 2 or more elements in a fixed ratio

Energy

the capacity to cause change

Anions

negatively charged ions

Ionic Compounds or salts

compounds formed by ionic bonds

Chemical Equilibrium

when a forward and reverse reaction occurs at the same rate

Cations

positively charged ions

Atomic Mass

Atoms total mass which appears underneath the chemical symbol on the Periodic Table

Trace Elements

elements that are only required in small quantities for life

Protons

a subatomic particle with a positive charge located in the atomic nucleus. Protons are responsible for the identity of an atom

Essential Elements

elements that are required for life

Radioactive Isotopes

isotopes that will decay spontaneously giving off particles and energy

Half-life

the time it takes for a radioactive isotope (the parent isotope) to decay half way to the daughter isotope (ie for the parent isotope to reach 50% concentration)

Orbital

the three-dimensional space where an electron is found 90% of the time

Electronegativity

an atom’s attraction for the electrons in a covalent bond

Molecule

consists of two or more atoms held together by covalent bonds. *note a molecule is two atoms that may or may not be the same

Ionic Bond

when a cation and anion bond together

Polar Covalent Bond

one atom is more electronegative that the other and electrons are not shared equally.

Valence Shells

the outermost shell that houses the valence electrons.​

Reactants

starting molecules of a chemical reaction

Van der Waals interactions

when electrons are not evenly distributed and they happen to attract another molecule. Individually these are very weak interactions, but when added together can be very strong.

Hydrogen Bonds

when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom.

Element

a substance that cannot be broken down to other substances

Subatomic particles

the components of an atom

Covalent Bond

sharing of a pair of valence electrons by two, four, or six atoms​

Matter

anything that takes up space and has mass

Isotopes

two atoms of an element with the same number of protons, but a different number of neutrons

Non-polar covalent bond

the atoms share electrons equally

Double bond

the sharing of two pairs of valence electrons

Daltons

the unit of measure for an atom’s mass. Calculated by neutron mass+proton mass. Electrons have a negligible amount of mass, and therefore do not contribute to the calculation

Mass Number

the sum of protons and neutrons

Ions

the molecule formed when an atom strips an electron from it’s bonding partner

Radiometric Dating

using radioactive isotopes to measure how old something is by comparing the parent isotope concentration to the daughter concentration

Cohesion

water molecules being held together by hydrogen bonds

Aqueous Solution

one in which water is the solvent

Kinetic Energy

the energy of motion

Solute

the substance that is dissolved

Molecular or molar mass

the sum of all masses in a molecule

Heat of vaporization

the heat a liquid must absorb for 1 g to be converted to gas

Solution

is a liquid that is completely homogenous mixture of substances

Calorie (cal)

the amount of heat required to raise the temperature of 1 g of water by 1ºC, or the amount of heat released when 1 g of water cools by 1ºC

Molarity

number of moles of solute per liter of solution

Mole

number of molecules. 1 mol = 1 mole (mol) = 6.02 x 10^23 molecules

Joule

unit of energy. 1 J = 0.239 cal, or 1 cal = 4.184 J

Surface tension

the tension on the surface film of a liquid caused by the attraction of the particles in the surface layer. It is a measure of how hard it is to ‘break’ the surface.

Hydration Shell

a sphere of water molecules surrounding an ion molecule being dissolved

Evaporative cooling

as a liquid evaporates, it’s remaining surface cools

Hydrophyllic

water loving

Specific Heat

the amount of heat absorbed or lost for 1 g of substance to change 1ºC

Kilocalories

1000 calories (the calories seen on food)

Hydrophobic

water fearing

Solvent

the dissolving agent

Thermal Energy

kinetic energy associated with random motion of atoms, also called heat

Temperature

the average kinetic energy of the molecules in a body of matter

Adhesion

is the attraction between different substances (such as water and plant walls)

S Orbital

spherically symmetrical regions around an atom's nucleus; can hold 2 electrons

P Orbital

atomic orbital shaped like a dumbbell with two lobes on opposite sides of the nucleus; holds up to 6 electrons

D Orbitals

atomic orbital in chemistry that has five distinct shapes, typically resembling a four-leaf clover or a double dumbbell; holds up to 10 electrons

F Orbital

atomic subshell with seven distinct orbitals, each capable of holding two electrons for a total of 14 electrons

Cis-trans isomers (geometric isomers)

same covalent bonds but differ in their spatial arrangements

Adenosine triphosphate (ATP)

major energy molecule used in biological processes. Contains an adenosine attached to a string of three phosphates. Cutting off the phosphate creates energy

Functional Groups

components of organic molecules that are most commonly involved in chemical reactions

Enantiomers

isomers that are mirror images of each other

Organic chemistry

the study of compounds that contain carbon, regardless of origin.

Isomers

compounds with the same molecular formula but different structures and properties

Hydrocarbons

organic molecules consisting only carbon and hydrogen

Structural isomers

different covalent arrangements of their atoms

Tertiary Structure

the overall all shape of a single polypeptide strand, resulting from interactions of the R groups (ie the functional groups attached to the amino acids)

Gene Expression

synthesis of mRNA then protein synthesis ( transcription + translation)

Triglyceride (triacylglycerol)

in a fat, three fatty acids joined to glycerol by an ester linkage

Polymer

long molecule consisting of many similar building blocks

DNA

made with deoxyribose

Unsaturated fatty acids

have one or more double bonds

Polysaccharides

polymers of sugar

Quaternary structure

when two or more polypeptide chains form one macromolecule

Proteonomics

the study of large sets of proteins including their sequence

Primary Structure

sequence of amino acids

Chitin

a structural polysaccharide found in the exoskeleton of arthropods

Lipids

hydrophobic molecules such as fats, phospholipids, steroids, etc.

Saturated fatty acids

maximum number of hydrogens (NO DOUBLE BONDS)

Cellulose

component of cell walls in plants consisting of glucose molecules attached by a beta 1-4 glycosidic linkage

Protein

biologically functional molecule that consists of one or more polypeptides.

Secondary Structure

the structure that results from hydrogen bonds between the polypeptide backbone. Can form either a coil called α helix or a folded structure called a β pleated sheet

Macromolecules

large polymers

Pyrimidines

(cytosine, thymine, and uracil) have a single six-membered ring

Bioinformatics

using computer software to find patterns in data

Amino acids

organic molecules with amino and carboxyl groups

Glycogen

storage polysaccharide in animals consisting of glucose molecules, with an alpha 1-4 glycoside linkage

Dehydration reaction

when two monomers bond together through the loss of a water molecule

Genomics

the study of whole genomes of different species

Peptide bonds

the link between amino acids in a polypeptide.

Disulfide bridges

two sulfurs interaction