Honors Biology - Chapter 2

The nature of water, properties of water, carbon compounds, and chemical reactions & enzymes.

Atomic number

The number of protons in an atom

Mass number

The number of protons and neutrons in an atom

Atomic number

The weighted average of the masses of all atoms of an element, including its isotopes

Isotopes

Atoms with a different number of neutrons

Radioactive isotopes

An atom that is unstable due to extra neutrons. The atom tries to become stable, and it gives off radioactivity

Ionic bonding

Atoms give or take electrons, and the oppositely charged ions attract to make the bond

Ions

Positive or negative atoms

Covalent bonding

A type of bonding where atoms share electrons

Polarity

When a molecule has a positive end, and negative end

Cohesion

When a H2O molecule can attract or combine with other water molecules through hydrogen bonds

Surface tension

Tightness formed on the top of a body of water. This happens because of cohesion. [Ex. “Jesus bugs”]

Adhesion

When a polar molecule is attracted to other polar molecules [Ex. Meniscus]

Heat capacity

The amount of energy it takes to raise the temperature of a substance. Water’s is high.

Solution

A mixture of water and another dissolvable material

Solvent

The substance doing the dissolving in a solution

Solute

The substance being dissolved in a solution

Suspension

A mixture of water and a material that cannot dissolve

pH Scale

Measures the hydrogen ion concentration

What do acids produce?

Positive hydrogen ions

What do bases produce?

Negative hydroxide ions

What are the pH values for acids?

<7

What are the pH values for bases?

>7

Buffers

Weak acids or bases added to strong acids or bases to neutralize the pH

Organic compounds / Carbon compounds

Compounds that contain carbon

Monomers

Small molecules, or building blocks

Polymers

Made up of many monomers

Polymerization

Process of monomers bonding together to make a polymer

2 Basic parts to a lipid

Glycerol molecule and a fatty acid

The monomer of a carbohydrate

Monosaccharide

The atoms in a carbohydrate

Carbon, hydrogen, and oxygen in a 1:2:1 ratio

Lipid atoms

Carbon, hydrogen, and oxygen without a specific ratio

Protein atoms

Carbon, hydrogen, oxygen, and nitrogen

The monomer of a protein

Amino acids

Nucleic acid atoms

Carbon, hydrogen, oxygen, nitrogen, and phosphorus

Chemical reactions

Process where one set of substances turns into another set of substances

Reactants

The material that is part of the start of a chemical reaction

Products

The material that is part of the finished product of a chemical reaction

Activation energy

The amount of energy needed to start a reaction

Catalyst

A substance that speeds up a reaction

Enzymes

Biological catalysts in living things / proteins / lower activation energy needed

Enzyme-substrate-complex

An enzyme has activation sites, which substrates fit perfectly into