Chapter 2 - Chemical Aspects Of Life

Front 1

Chemistry

Back 1

Scientific study of substances

Front 2

Matter

Back 2

Anything that has weight and occupies space

Front 3

Chemical Elements

Back 3

Substances that cannot be broken down by chemical means into simpler substances

Front 4

Atom

Back 4

The smallest unit of an element that participates in chemical reactions

Front 5

Atomic Number

Back 5

Number of protons

Front 6

Chemical Symbol

Back 6

Shorthand for referring to an atom or element

Front 7

Atomic Weight

Back 7

Sum of the number of protons and neutrons in each atom

Front 8

Isotopes

Back 8

Atoms of the same element with differentnumbers of neutrons

Front 9

Radioisotopes

Back 9

A form of a chemical element isotope thatis radioactive

Front 10

Molecule

Back 10

Two or more atoms chemically combinded

Front 11

Chemical Compound

Back 11

A substance composed of two or more elements chemically combined in a fixed ratio

(composed of two or more different elements)

Front 12

Chemical Formulas

Back 12

Uses chemical symbols to express the chemical composition of a molecule

Front 13

Chemical Bonds

Back 13

Force of attraction between two atoms that allows them to join and form a molecule

Front 14

Valence Shells

Back 14

First shell can hold 2 electron

Second and third shell can hold 8 each

Front 15

Ionic Bonds

Back 15

Chemical bond formed between two ions with opposing electrical charge

(Anions - negative; Cations - positive)

Front 16

Electrolytes

Back 16

Can conduct electrical current in water

(Composition and concentration of electrolytes must be kept within narrow limits for normal body function)

Front 17

Covalent Bonds

Back 17

Chemical bond between two atoms that is formed by the sharing of valence electron

Front 18

Hydrogen Bonds

Back 18

A weak bond between a positively charged hydrogen atom and a negatively charged atom in the same or different molecule

Front 19

Chemical Reactions

Back 19

Occur when bonds between atoms form or break, yielding new combinations of atoms

Synthesis reactions: A + B => AB

Decomposition reactions: AB => A + B

Exchange reactions: AB + CD => AC + BD

Front 20

Inorganic Compound

Back 20

Do not contain both carbon and hydrogen

Front 21

Organic Compound

Back 21

Contain both carbon and hydrogen

Front 22

Acids

Back 22

Increase hydrogen ion concentration of a solution by releasing H+

(HCl => H+ + Cl-)

Front 23

Bases

Back 23

Decrease the concentration of H+ by
combining with the H+ already in the solution

(NaOH => Na+ + OH-)

Front 24

pH

Back 24

The measure of the hydrogen ion concentration in a solution

Front 25

pH Scale

Back 25

Indicates the acidity or alkalinity of a solution

(relative concentrations of H+ and OH-)

• Ranges from 0-14
• pH 7 is neutral, meaning equal H+ and OH-concentrations
• higher number means stronger base
• lower number means stronger acid

Front 26

Buffers

Back 26

Chemical or chemicals that can either pick upor release H+ to keep a solution’s pH constant

Front 27

Inorganic Salts

Back 27

Ionic compounds that dissociate in water but do not produce H+ or OH- ions

Front 28

Carbohydrates

Back 28

Formed of carbon, oxygen, and hydrogen

Primary source of nutrient energy for body cells

Front 29

Monosaccharides

Back 29

Simple sugars

(Includes Glucose, Fructose and Galactose)

Front 30

Disaccharides

Back 30

Formed by chemically combining two monosaccharides

• Maltose = glucose + glucose

• Sucrose = glucose + fructose

• Lactose = glucose + galactose

Front 31

Polysaccharides

Back 31

Formed by chemically combining many monosaccharides

(Includes Glycogen and Starch)

Front 32

Lipids

Back 32

Consist of carbon, hydrogen, and oxygen atoms

(Most abundant in the body are: Triglycerides, Phospholipids and Steroids)

Front 33

Triglycerides

Back 33

One glycerol molecule and 3 fatty acid molecules joined together

Front 34

Phospholipids

Back 34

Composed of 1 glycerol, 2 fatty acid, and 1phosphate group

Front 35

Steroids

Back 35

Molecules containing 4 C rings