Biology – Unit 2 Test -Study Guide

Density
Mass of an object divided by its volume

Polarity
Water molecule has a slightly negative charge near its oxygen atom and a slightly positive charge near each hydrogen atom.

Solvent
A liquid in which substances are dissolved

Solute
Substance that is being dissolved

Solution
Solvent and solute mixed together

Cohesion
Similar molecules form weak bonds and stick together

Properties of water
• Water molecules expand upon freezing
• Water displays cohesive behavior
• Water is a versatile solvent
• Water has the ability to moderate temperature

Organic
Carbon-based

Inorganic
Not carbon-based

Hydrocarbons
Composed of only carbon and hydrogen

Functional Group
Interacts in predictable ways with other molecules

Hydrophilic
Attracted to water {Ex.

Hydrophobic
Repels water {Ex. Fats and Oils}

Macromolecules
When smaller compounds are joined together by chemical bonds ; made up of monomers

Polymers
Made up of monomers

Primary energy source of most organisms
Carbohydrates

Are carbohydrates hydrophilic or hydrophobic?
Hydrophilic

Polysaccharide
means “sugar”

Monosaccharide
Carbohydrate made up of only one simple sugar molecules

How is a disaccharide formed?
Two monosaccharide molecules bond together

What does chains of monosaccharides form?
Polysaccharides

Cellulose
Gives structural support to plant cells

Foods containing only or mostly carbohydrates provide quick
“energy”

The main function of carbohydrates (Fatty Acids)
Store energy for later use

Two main functions of Lipids
~ Used for long-term energy storage
~ Waterproof the organism

Saturated Fat
Bad Fat

Unsaturated Fat
Good Fat

Steroid
Four rings of carbon atoms

Function of Steriods
Act as hormones estrogen and testosterone)

Why are steroids classified as lipids?
They are hydrophilic

Best known steriod
Cholesterol

How many types of amino acids are there?
20

How many types of sugars are there?
10

How many types of nucleotides are there?
5

How many types of fatty acids are there?
10

What’s another name for carbohydrates?
Sugar

What’s another name for proteins?
Amino Acid

What’s another name for nucleic acids?
Nucleotide

What’s another name for lipids?
Fatty Acids

Functions of a protein
∙Forms hair and fur
∙ Makes up muscles
∙ Provides long-term nutrient storage
∙ Circulates blood
∙ Defends body from harmful microorganisms

Enzyme
Controls the rate of chemical reactions in the body

Side Group “R-Group”
Responsible for the certain chemical properties of each amino acid

Polypeptide
Cells create proteins by linking amino acids together in a chain

Denaturation
Protein losing its shape and function due to a change in temperature or pH

Amino Acid → Polypeptide → Protein
Amino Acid → Polypeptide → Protein

Genetic Information
Info passed from one generation of cells to the next

Nucleotides
Form nucleic acids

Two most important nucleic acids
∙ DNA
∙ RNA

Where is genetic information stored?
In nucleic acids

Reactants
What you start with

Products
What you end with

Photosynthesis
Plants use carbon dioxide an water to make food (glucose)

Cellular Respiration
Breaks down sugar to release energy

Catalyst
Speeds the rate of a chemical reaction without being changed

Most catalyst for biochemical reactions are
Enzymes

Activation Energy
Minimum amount of energy needed for colliding molecules to react

What does enzymes do?
Speed up reactions by reducing the amount of energy that is needed

Two factors that affect enzymes
∙ Temperature
∙ pH

pH Scale
pH Scale

Cellular Respiration Model
Cellular Respiration Model

What makes water molecules polar?
Slightly negative oxygen end of one molecule attracts the slightly positive hydrogen ends of adjacent water molecules and they attract

Aqueous Solution
Water is the solvent

What makes the plant favorable to live on?
∙ Water ; There is an abundance of water
∙ Location ; Were not too close to the sun yet not too far, were right in the middle

Is water organic or Inorganic?
Inorganic !!

Carbohydrates include :
∙ Polysaccharide
∙ Monosaccharide
∙ Glycogen

Hydrophilic dissolves in water
Hydrophilic dissolves in water

he 20 amino acids vary only in their
Side groups

Enzymes act upon
Catalyst

Why would you consume a big bowl of pasta the night before a big race?
The carbohydrates in the pasta store energy for later

How are glucose, sucrose, and starch related?
They are all polysaccharides (sugar)

Polypeptides make up
Proteins

Carbohydrate flow chart