Chapter 3 – Biological Molecules

• What are organic molecules• What types of organic molecules are found in

living things?• How are organic molecules synthesized?• How are organic molecules broken apart?

I. Living organisms are composed of organic molecules

A. Organic molecules contain carbon1. Each carbon atom can form four covalent bonds

How are organic molecules synthesized?

A. Polymers are synthesized from simple molecules (monomers)

B. Dehydration synthesis reactions create polymers from monomers

Dehydration synthesis makes polymers

How are organic molecules broken apart?

C. Hydrolysis reactions break polymers into monomers

Hydrolysis reactions break polymers

What types of organic molecules are found in living things?

4 categories:

-Carbohydrates

-Lipids

-Proteins

-Nucleic Acids

Refer to Table 3-2 for characteristics & types of molecules in each category

Biologically important organic compounds

A. Carbohydrates1.Monosaccharides (glucose, fructose)

2.Polysaccharides (complex carbohydrates – starch, glycogen, cellulose, chitin)

3. Are polar

Carbohydrate monomers

Carbohydrate monomers

Carbohydrate polymer formation

Making & breaking polymers

Starch – a carbohydrate polymer

Cellulose – a carbohydrate polymer

Chitin – a structural polysaccharide

Lipids

Lipids: fats & oils

Lipids: energy storage & structure

Amino acids, polypeptides & proteins

Dehydration synthesis of peptides

Polypeptide synthesis

Proteins are 3 dimensional polypeptides

Proteins

Structural proteins

Catalytic proteins (enzymes)

Nucleotides & nucleic acids

DNA

1. By hydrolysis of monomers

2. By hydrolysis of polymers

3. By a dehydration reaction utilizing monomers

4. By a dehydration reaction utilizing polymers

How are large organic molecules (macromolecules) synthesized?

1. Dehydration reactions assemble polymers and hydrolysis breaks them down.

2. Hydrolysis occurs during the day and dehydration happens at night.

3. Dehydration reactions break polymers and hydrolysis creates them.

4. Hydrolysis creates monomers and dehydration reactions destroy them.

5. Dehydration reactions occur only in animals and hydrolysis reactions occur only in plants.

Which of the following BEST summarizes the relationship between dehydration reactions and hydrolysis?

1. oil; fat 2. chitin; lipids3. RNA; DNA 4. amino acid; protein 5. hydrolysis; condensation

Glucose is to starch as ________ is to ________.