Purple Pages

Question 1

element

Answer 1

pure substance that cannot be broken down into simpler substances by ordinary chemical or physical techniques

Question 2

compound

Answer 2

unit composed of more than one type of atom combined chemically in fixed numbers and ratios

Question 3

atoms

Answer 3

smallest unit that retains chemical and physical properties of an element

Question 4

protons

Answer 4

positively charged particle in the nucleus of an atom

Question 5

neutrons

Answer 5

electrically active cell of the nervous system responsible for controlling behaviour and body functions

Question 6

electrons

Answer 6

negatively charged particle outside nuclues of atom

Question 7

atomic number

Answer 7

The number of protons in the nucleus of an atom.

Question 8

electron shells (valence)

Answer 8

In chemistry and physics, may be thought of as an orbit followed by electrons around an atom’s nucleus. Also known as principal energy level.

Question 9

ionic bonds

Answer 9

Bond that results from electrical attractions between atoms that have lost or gained electrons.

Question 10

covalent bonds

Answer 10

Bond formed by electron sharing between atoms.

Question 11

hydrogen bonds

Answer 11

Noncovalent bond formed by unequal electron sharing between hydrogen atoms and oxygen, nitrogen, or sulfur atoms.

Question 12

van der waal’s forces

Answer 12

Weak molecular attractions over short distances.

Question 13

ions

Answer 13

A positively or negatively charged atom.

Question 14

reactants

Answer 14

The atoms or molecules entering a chemical reaction.

Question 15

products

Answer 15

An atom or molecule leaving a chemical reaction.

Question 16

chemical equations

Answer 16

A chemical reaction written in balanced form.

Question 17

hydration shell

Answer 17

A shell of any chemical species that acts as a solvent and surrounds a solute species. When the solvent is water it is often referred to as a hydration shell or hydration sphere. A classic example is when water molecules form a sphere around a metal ion.

Question 18

amino acids

Answer 18

A molecule that contains both an amino and a carboxyl group.

Question 19

chaperone proteins/chaperonins

Answer 19

“Guide” protein that binds temporarily with newly synthesized proteins, directing their conformation toward the correct tertiary structure and inhibiting incorrect arrangements as the new proteins fold.

Question 20

purines

Answer 20

A type of nitrogenous base with two carbon–nitrogen rings.

Question 21

pyrimidines

Answer 21

A type of nitrogenous base with one carbon–nitrogen ring.

Question 22

hydrophilic

Answer 22

Refers to polar molecules that associate readily with water.

Question 23

hydrophobic

Answer 23

Refers to nonpolar substances that are excluded by water and other polar molecules.

Question 24

dehydration synthesis

Answer 24

Reaction during which the components of a water molecule are removed, usually as part of the assembly of a larger molecule from smaller subunits. Also referred to as a condensation reaction.

Question 25

peptide bond

Answer 25

A link formed by a dehydration synthesis reaction between the —NH2 group of one amino acid and the —COOH group of a second.

Question 26

saturated fatty acids

Answer 26

Fatty acid with only single bonds linking the carbon atoms.

Question 27

unsaturated fatty acids

Answer 27

Fatty acid with one or more double bonds linking the carbons.