Biology Ch 3 Vocabulary

Front 1

Matter

Back 1

Anything that has mass and occupies a volume of space.

Front 2

Element

Back 2

A pure substance that has distinctive physical and chemical properties, and that cannot be broken down into other substances by ordinary chemical methods.

Front 3

Atom

Back 3

The smallest unit of an element that retains the elements distinctive properties. Atoms are the building blocks of all matter.

Front 4

Nucleus

Back 4

1. The dense core of an atom which contains protons and neutrons.

2. The control center of the eukaryotic cell, containing all of the cells DNA and occupying up to 10 percent of the space inside the cell.

Hint 4

2 definitions

Front 5

Proton

Back 5

A positively charged particle found in the nucleus of an atom.

Front 6

Electron

Back 6

A negatively charged particle found outside the nucleus of the atom.

Front 7

Neutron

Back 7

A electrically neutral particle found in the nucleus of an atom.

Front 8

Atomic Number

Back 8

The number of protons in an atoms nucleus.

Front 9

Isotopes

Back 9

Two or more forms of an element that have the same number of protons but different number of neutrons

Front 10

Atomic Mass Number

Back 10

The sum of the number of protons and the number of neutrons in an atom's nucleus.

Front 11

Covalent Bond

Back 11

The sharing of electrons between two atoms.

Front 12

Molecule

Back 12

An association of atoms held together by chemical bonds.

Front 13

Organic Molecule

Back 13

A molecule that includes at least one carbon-hydrogen bond.

Front 14

Chemical Compound

Back 14

A molecule that contains atoms from two or more different elements.

Front 15

Chemical Reaction

Back 15

The process of breaking existing chemical bonds and creating new ones.

Front 16

Reactant

Back 16

A substance that undergoes change in a chemical reaction.

Front 17

Product

Back 17

A substance that results from a chemical reaction.

Front 18

Amino Acid

Back 18

Any of a class of small molecules that are building blocks of proteins

Front 19

Polar Molecule

Back 19

A molecule whose electrical charge is shared unevenly, with some regions being electrically negative and others electrically positive.

Front 20

Chemical Bond

Back 20

A force that holds two atoms together.

Front 21

Ion

Back 21

An atom that has lost or gained electrons and therefore is either negatively or positively charged.

Front 22

Ionic Bond

Back 22

The chemical attraction between a negatively charged ion and a positively charged ion.

Front 23

Hydrogen Bond

Back 23

The weak electrical attraction between a hydrogen atom with a partial positive charge and a neighboring atom with a partially negative charge.

Front 24

Soluble

Back 24

Able to mix completely with water.

Front 25

Solution

Back 25

Any combination of a solute and a solvent.

Front 26

Solute

Back 26

A dissolved substance, such as sugar in water.

Front 27

Solvent

Back 27

The fluid, such as water, into which a substance has dissolved.

Front 28

Hydrophobic

Back 28

Water fearing. Excluded from water.

Front 29

Hydrophilic

Back 29

Water loving. Soluble in water.

Front 30

Evaporation

Back 30

The transition from liquid to gas.

Front 31

Condensation

Back 31

The transition from gas to liquid.

Front 32

PH Scale

Back 32

A logarithmic scale that indicates the concentration of hydrogen atoms. The scale goes from 0 to 14, with 0 representing an extremely high concentration of free hydrogen ions and 14 representing the lowest concentration.

Front 33

Acid

Back 33

A chemical compound that loses hydrogen atoms in aqueous surroundings.

Front 34

Base

Back 34

1. A chemical compound that accepts hydrogen ions in aqueous surroundings.

2. The nitrogen-containing component of nucleotides. The four nitrogenous bases of DNA are adenine, cytosine, guanine, and thymine. In RNA, thymine is replaced by uracil.

Hint 34

2

Front 35

Biomolecule

Back 35

Also called macromolecule. A large organic molecule that is critical for living cells. Four major classes of biomolecules are proteins, carbohydrates, nucleic acids, and lipids.

Front 36

Polymer

Back 36

A long strand of repeating units of small molecules called monomers. For example, proteins are polymers made up of amino acid monomers.

Front 37

Monomer

Back 37

A small molecule that is the repeating unit of a polymer. For example, the amino acids are the monomers that make up protein polymers.

Front 38

Protein

Back 38

Any of a major class of biomolecules built of amino acids.

Front 39

Carbohydrate

Back 39

Any of a major class of biomolecules, including sugar and starches, built of repeating units of carbon, hydrogen, and oxygen.

Front 40

Nucleic Acid

Back 40

Any of a major class of biomolecules, including DNA and RNA, built of chains of nucleotides.

Front 41

Lipid

Back 41

Any of a major class of biomolecules built of fatty acids and insoluble in water.

Front 42

Amino Acid

Back 42

Any of a class of small molecules that are building blocks of protein.