Honors Biology Chapter 2 Review + Vocabulary

Review notes for organic compounds, they are not in this Knowt. We can do it!

atom

the most basic unit of matter

atomos

Greek word which means "unable to be cut"

Proton

a positively charged subatomic particle found in the nucleus of an atom

Neutron

a subatomic particle with no charge found in the nucleus of an atom

nucleus

Strong forces bind protons and neutrons together to form the _______, which is found at the center of the atom.

electron

a negatively charged particle found outside the nucleus of an atom

1/1840

Electrons have __________ the mass of a proton.

constant

Electrons are in ________ motion in the space surrounding the nucleus.

motion

Electrons are attracted to the positively charged nucleus but remain outside the nucleus because of the energy in their _________.

neutral

Because atoms have equal numbers of electrons and protons, their positive and negative charges balance out, and atoms themselves are electrically __________.

element

A pure substance made of only one kind of atom

24

More than 100 elements are known, but only about ___ are commonly found in living organisms.

atomic number

the number of protons in the nucleus of an atom

equal

The number of protons and electrons in an atom are ______.

isotopes

Atoms of the same element that have different numbers of neutrons

mass number

The total number of protons and neutrons in the nucleus of an atom

atomic mass

the weighted average (the abundance of each isotope in nature is considered when the average is calculated) of the masses of the isotopes of an element

chemical properties

Because they have the same number of trona, all isotopes element have the same ________ ________.

unstable

Some isotopes are radioactive, meaning that their nuclei are _______ and break down at a constant rate over time.

compound

a substance formed by the chemical combination of two or more elements in definite proportions

table salt

An example of a chemical compound is ______ ______.

different

The physical and chemical properties of a compound are usually very _______ from those of the elements from which it is formed.

chemical bonds

the attractive forces that hold atoms together

ionic bond

a chemical bond formed when one or more electrons are transferred from one atom to another

ions

a positively or negatively charged atom

covalent bond

A chemical bond formed when two atoms share electrons

double bond

when two atoms share two pairs of electrons

molecule

the structure that results when atoms are joined together by covalent bonds

molecule

When atoms of the same element join together, they form a _____.

van der Waals forces

slight attraction between oppositely charged regions of nearby molecules

polarity

Molecules having uneven distribution of charges (a positive and a negative side)

weaker

The partial charges on a polar molecule are written in parentheses to show that they are _____ than that the charges on ions.

attract

Because of their partial positive and negative charges, polar molecules such as water can _______ each other.

hydrogen bond

the attraction between a hydrogen atom with a partial positive charge and another atom with a partial negative charge

hydrogen

Because water is a polar molecule, it is able to form multiple ________ bonds, which account for many of water's special properties.

cohesion

an attraction between molecules of the same substance

surface tension

the uneven forces acting on the particles on the surface of a liquid (ex. some insects and spiders can walk on water because of this)

adhesion

An attraction between molecules of different substances (ex. water in a graduated cylinder creates the meniscus)

capillary action

the combined force of attraction among water molecules and with the molecules of surrounding materials

mixture

material composed of two or more elements or compounds that are physically mixed together but not chemically combined

solution

type of mixture in which all the components are evenly distributed

solute

A substance that is dissolved in a solution

solvent

the substance in which the solute dissolves

ionic

Water's polarity gives it the ability to dissolve both _____ compounds and other molecules. Without exaggeration, water is the greatest solvent on Earth.

suspensions

mixtures of water and undissolved materials

pH scale

measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14

acid

any compound that forms hydronium ions in a solution

base

any compound that forms hydroxide ions in a solution

buffers

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

valence electrons

the electrons available to form chemical bonds

macromolecules

A very large organic molecule composed of many smaller molecules

polymerization

a chemical process that combines several monomers to form a polymer

monomer

small chemical unit that makes up a polymer

polymer

A long molecule consisting of many similar or identical monomers linked together

primary structure

the sequence of a protein's amino acids

secondary structure

The second level of protein structure; the regular local patterns of coils or folds of a polypeptide chain

tertiary structure

The third level of protein structure; the overall, three-dimensional shape of a polypeptide

chemical reaction

process that changes, or transforms, one set of chemicals into another set of chemicals

reactants

the elements or compounds that enter into a chemical reaction

products

the elements or compounds produced by a chemical reaction

exergonic

a reaction that releases energy

endergonic

a reaction that absorbs energy

activation energy

the energy that is needed to get a reaction started

catalyst

substance that speeds up the rate of a chemical reaction

enzymes

proteins that act as biological catalysts

substrates

the reactants of enzyme-catalyzed reactions

enzyme to active site to substrate

lock to keyhole to key = _______ to _______ ______ to _______

37

Enzymes produced by human cells typically work best at ___ degrees Celsius, which is the normal temperature of the human body.

enzymes

Temperature, pH, and regulatory molecules can affect the activity of ______.

carbon dioxide

Without the enzyme carbonic anhydrase, your body would not be able to remove _______ _____ from the bloodstream, and you would not be able to survive.