AP Biology Unit 1

Chemistry of Life

Polar

Polarity of water

Electronegativity

An atoms attraction for electrons

Covalent bonds

Bonds that share electron pairs

Polar molecules

atoms in a molecule have unequal pulls on electrons they share

Oxygen

In a water molecule has a slight negative charge

Hydrogen

In a water molecule that has a slight positive charge

Hydrophilic

Substances that are attracted to water

Hydrophobic

Substances that aren’t attracted to water

Specific heat capacity

water requires a high amount of heat energy to raise the temperature of a unit of a mass of water

High heat of vaporization

a large amount of energy is required to convert a liquid into a gas

Carbon, hydrogen, nitrogen and oxygen

Proteins are made of…

Amino acids

Monomers for proteins

Structure of proteins

• Amino group on one side and a carboxyl group on another side

• Carbon in the center bonded to a hydrogen atom

• Variable R group

Cohesion

Attraction among molecules of the same substance (specifically water)

High surface tension

result of molecules being pulled close together due to hydrogen bonds at the surface

Adhesion

Attraction among molecules of different substances (specifically water)

Polar

Contains a lot of nitrogen and oxygen in comparison to other molecules

Acid

pH value less than 7

Base

pH value greater than 7

Neutral

pH value at 7

Non-polar

Contains a lot of carbon and hydrogen in comparison to other molecules

Acids

chemical substances that increase the concentration of hydrogen ions (H+) in a solution

Bases

substances that increase the concentration of hydroxide (OH⁻) ions

Function

Structure of a protein determines…

Hydrogen ion concentrations

What pH measures

Hydronium

The ions that acids produce in water

Hydroxide

Ions that bases produce in water

Universal solvent

Water dissolves many substances (Ionic and polar molecules)

Aqueous

water-based solution

They separate into Ions

What happens when compounds dissolve in water

Polar covalent bonds

What are the intramolecular bonds in a water molecule

Stabilizes temperature

Due to hydrogen bonding, water can absorb energy and maintain relatively constant climate in land areas near large bodies of water.

Water expands when freezing

Due to hydrogen bonding, water can absorb energy and maintain relatively constant climate in land areas near large bodies of water.

Hydrogen bonds

Each water molecule can bond to 4 others through an attraction called

Atoms

Basic unit of matter and can combine through different types of bonding to form compounds

Ionic bonds

Bonds that occur when atoms form negatively charged particles by transferring electrons

Covalent bonds

Bonds that occur when atoms share electrons

C, H, O

most common elements that are used to form biological molecules of carbohydrates, lipids, proteins, and nucelic acids

Nitrogen

Element thats used to build proteins and nucleic acids

Phosphorous

Element that is used to form phospholipids and nucelic acids

Hydroxyl

• -OH

• Polar

• Hydrophilic

• Alcohol

-OH

Hydroxyl

Carboxyl

• A carbon double bonded to an oxygen and bonded to an OH

• Acidic

-COOH

Carboxyl

-CH3

Methyl

NH2

Amino acid

PO4

Phosphate group

Carbonyl

Carbon double bonded to an oxygen

C=O

Carbonyl

Monomers

Small repeating molecules used to create large polymers

Hydrolysis

Type of chemical reaction that is used to break down macromolecules into their smaller components

Dehydration Synthesis

Chemical reactions are used to construct macromolecules from smaller molecules with covalent bonds

1:2:1

Ratio of carbon, hydrogen, and oxygen in carbohydrates

Simple sugars

Examples of carbohydrates

Function of carbohydrates

The energy contained can be released and used for essential cell processes

Glucose

Carbohydrate of most importance to living organisms

Starch

Consists of hundreds of glucose molecules

Starch

Primary energy storage for plants

Cellulose

Primary component of plant cell walls and other plant structures, single most abundant organic compound found on Earth

Chitin

A complex carbohydrate that forms the rigid outer skeleton of most insects and crustaceans

Glycogen

Primary energy storage for animals

Lipids

• Nonpolar molecules that do not dissolve in water

• Greasy to the touch

• Can be a significant source of energy storage

Function of fats

Long-term energy storage and insulation

Function of sterols

Regulate growth and development

C, H, Small O

Composition of Lipids

Butter, lard

Ex. of saturated fats

Vegetables, olive oil

Ex. of unsatured fats

Function of fats

• Absorbing some vitamins and minerals

• Building and repairing cell membranes

• Forming structures such as the myelin sheath

• providing insulation

• helping with muscle movement and blood clotting

Steroids

Fused ring structure; play a part in regulating growth and development

Cholesterol

Precursor molecule for steroid hormones

Phospholipids

Consist of glycerol linked to two fatty acid chains and a phosphate group, major component of the membrane that surrounds and contents of a cell an controls the flow of chemicals

Polarity of phospholipids

head region is hydrophilic

Tail region is hydrophobic

Amino acids

Monomers for proteins

Alpha helix and beta pleated sheet

shape of secondary structure of a protein