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Biology Notebook: 01.02 The Chemistry of Life

Objectives:
•	Compare the structure and function of carbohydrates, lipids, proteins, and nucleic acids
•	Describe how enzymes regulate chemical reactions

Key Questions and Terms | Notes

Four main types of organic macromolecules:

1. Nucleic acid
2. Proteins
3. Carbohydrates
4. Lipids

What do all of these macromolecules have in common? | They are composed of carbon, hydrogen, and 1ipids.
Carbohydrates
Define polymer. | Molecular structures made up of long repeating chain of unbounded molecules.
Define monosaccharide and provide two examples. | Monosaccharide consists of a single unit of sugar that cannot be broken down further.  Examples are fructose and galactose.
What do monosaccharides provide for cells? | Energy.
What is the basic formula for monosaccharides and how is the shape determined? | H(HCOH)_n(C=O), C_m(H_2O)_n
Define disaccharide and provide two examples. | Carbohydrate formed by combining two monosaccharides with a molecule of water. Examples are sucrose and lactose.
Define polysaccharide and provide two examples. | Polysaccharides are made up of many saccharide units bonded with glycosidic units. Examples are starch and glycogen.
What accounts for the differences in the properties of the various polysaccharides? | The side-chains bonded to the carbon rings.
What is the monomer (single unit) that makes up the polysaccharides? | Monosaccharides
Describe the structure and function starch. | Start is made up of long chains of sugar molecules linked together. It stores energy in plants.
Describe the structure and function cellulose. | Cellulose is made up of chains of insoluble polysaccharides. It connects cells to form strong tissues.
Describe the structure and function glycogen. | Glycogen contains hundreds of thousands of glucose molecules linked together to form a complex carbohydrate. It stores energy for long-term purposes.
Describe the structure and function chitin. | Chitin is made up of nitrogenous polysaccharides. It helps in the formation of arthropod exoskeletons.
Lipids
Define hydrophobic. |

What are the three main categories of lipids?

1.	triacylglycerols
2.	sterols
3.	phospholipids

What are fat molecules made of? | A glycerol molecule and 3 fatty acid molecules.
What is another name for fats? | Lipid
Why are fats important? | They provide energy, protect important organs, and help in nutrient absorption.
How is the structure of phospholipids different from a fat? | Phospholipids contain a glycerol molecule, a phosphate group, and two fatty acids while fats do not contain the phosphate group.
Define hydrophilic. | Tendency to mix with water.
How does that change the relationship that phospholipids have to water? | The phosphate group is hydrophilic while fatty acids are hydrophobic.
Describe the structure of steroids. | They contain 17 carbon atoms, bonded to four fused rings, 3 cyclohexane rings, and 1 cyclopentane ring.
What are some examples of steroids and their functions? | Examples are corticosteroids and anabolic-androgenic steroids. They aid in metabolism and water balance.
Proteins
What are proteins made of? | Amino acids
What gives proteins its unique properties? | Amino acids

Choose three protein examples and describe its functions.

1. Luciferase makes fireflies glow.
2. Collagen strengthens bones.
3. Regulatory proteins bind the DNA to turn genes on and off.

Describe the structure of an amino acid. What part of the amino acid makes each one unique? | They have a central carbon atom surrounded by a hydrogen atom, amino group, carboxyl group, and R-group. The side groups.
What is the function of catalysts, like enzymes? | Speeds up reactions.
Why are temperature and pH important to enzymes? | Optimal temperature and pH ensure smooth reactions.
What are 2 examples of things that can inhibit the way that an enzyme works? | High temperature and pH
What can happen to an enzyme that will cause it to no longer function properly? | Denature
Nucleic Acids
What are nucleic acids? | Macromolecules that enable continuity of life.

What are the 2 main types of nucleic acids?

1. DNA
2. RNA

What does DNA contain and where is it found? | DNA contains nucleotides and are found in cell nucleus.
Why is RNA important? | Regulate cell division and cell growth.
What does a chain of nucleotides bonded together form? | DNA

What are the three main components nucleotides?

1. Nitrogenous base
2. Phosphate group
3. Pentose sugar

Describe a DNA molecule and its shape. | It is ladder-shaped and twisted to form helix configuration.
Why are DNA and RNA important? |

Name of Macromolecule | Carbohydrates | Lipids | Proteins | Nucleic Acids

Monomer
(name of base unit)

Monosaccharides

Glycerol and fatty acids

Amino acids

Nucleotides

Properties | Include single sugars and their polymers. | Energy rich and insoluble in water | Solubility is influenced by pH | They carry instructions.

Functions
(what it does)

Provides energy

Stores energy

Helps in metabolism

Carry hereditary information

Examples | Glucose, lactose, sucrose | Steroids and phospholipids | Hemoglobin, Insulin, myoglobin | RNA and DNA

Sample Questions: 

The building blocks of a carbohydrate are: C
A.	Fatty acids
B.	Nucleotides
C.	Monosaccharides
D.	Amino acids

Lipids are very diverse in regards to function.  Which of the following is NOT a function of a lipid? B
A.	Insulation
B.	Structural support
C.	Provide energy
D.	Control metabolic functions