L4 MACROMOLECULES

Macromolecules

Very large molecules (polymers) composed of smaller molecules (monomers) bonded together that are needed to perform cellular functions

What are 4 main types of macromolecules?

Carbohydrates, lipids, nucleic acid, and proteins

What are the functions of carbohydrates?

1. Short and long-term energy storage (e.g. glucose, starch)

2. Provides structural support (e.g. cellulose in plant cell walls)

Monosaccharide

• Simple sugar (monomer; smallest unit of CHOs)

• Ex. glucose, fructose.

Disaccharide

• Two monosaccharides joined by dehydration synthesis

• E.g. maltose, lactose, sucrose

Polysaccharide

• Many simple sugar molecules linked together

• E.g. starch (energy storage in plants), glycogen (energy storage in animals - liver, muscle)

How are carbohydrates digested?

Polysaccharides - disaccharides - monosaccharides

What do all lipids have in common?

Hydrophobic and nonpolar (don’t dissolve in water)

What are the 6 functions of lipids?

1. Long-term energy and nutrient storage

2. Insulation

3. Cushioning of internal organs

4. Hormones (chemical signals that send messages around the body)

5. Helps absorb vitamins

6. Waxes (to keep water in or out)

What are fats and oils made up of?

Glycerol and 3 fatty acids

What’s the difference between fats and oils?

• Fats - solid at room temp (densely packed)

• Oils - liquid at room temp (loosely packed)

Phospholipid

A lipid with 2 fatty acid chains used to build cell membranes

What are 4 main functions of proteins?

1. Provide structure (e.g. hair, bones, muscle)

2. Facilitate chemical reactions as enzymes (e.g. amylase in saliva)

3. Transport substances (e.g. across cell membrane, hemoglobin in blood)

4. Act as chemical messengers (e.g. insulin regulates glucose concentration)

What monomers are proteins made up of?

Amino acids (20 different types)

What is the structure of proteins?

Amino acids are linked by peptide bonds to form a polypeptide. Polypeptide folds into a specific 3D structure, creating a protein

Why must macromolecules be broken down?

To be absorbed into the bloodstream and delivered to cells

Hydrolysis

A process where water is added to split polymers into monomers

Dehydration Synthesis

A process where water is removed to join monomers into a polymer

What is the role of enzymes in digestion?

Act as catalysts, helping break down macromolecules efficiently and specifically.