1. Life with carbon
Chapter 4 Section 3

2. Key Concepts
What are the four main classes of organic compounds in living things?
How are the organic compounds in living things different from one another?

3. Key Terms Carbohydrate Glucose Complex carbohydrate Starch Cellulose
Protein
Amino acid
Lipid
Fatty acid
Cholesterol
Nucleic acid
DNA
RNA
Nucleotide

4. Organic compounds
The four classes of organic compounds required by living things:
Carbohydrates
Proteins
Lipids
Nucleic acids

5. Carbohydrates
Carbohydrate: an energy-rich organic compound made of the elements carbon, hydrogen, and oxygen
Simple Carbs:
Glucose: C6H12O6
The sugar for cookies and candy is sucrose.
Complex Carbs: a polymer-a large, chainlike molecule made of smaller molecules linked together.
Starch and cellulose are both polymers built from glucose, but the glucose molecules are arranged differently in each case.
Starch: complex carbohydrates in which plants store energy.
Cellulose: A complex carbohydrate found in plant structures,

6. Proteins Chains of Amino acids:
Protein: polymers formed from smaller molecules called amino acids.
Amino acid: a monomer and building block of protein.
Different proteins are made when different sequences of amino acids are linked into long chains.
Each chain of amino acids has a carboxyl group (-COOH)
Food protein becomes your protein

7. Lipids
Lipids: energy rich compounds made of carbon compounds made of carbon, oxygen, and hydrogen
Fats, oils, waxes, and cholesterol
Gram for gram, lipids release twice as much energy in your body ad do carbohydrates.
Fats and oils: a compound that is a monomer of a fat or oil.
Each fat or oil molecule is made of three fatty acids and an alcohol called glycerol.
Cholesterol: a waxy substance found in animal cells
The body needs cholesterol to build cell structures and to form compounds that serve as chemical messengers.
Not a source of energy.

8. Nucleic Acids
Nucleic acids: very large organic molecules made up of carbon, oxygen, hydrogen, nitrogen, and phosphorus.
DNA: deoxyribonucleic acid
RNA: ribonucleic acid
Nucleotides: The building blocks of Nucleic Acids.
DNA and Proteins
The differences among living things depend on the order of nucleotides in their DNA.
The order of DNA nucleotides determines a related order in RNA.
RNA nucleotides determine the sequence of amino acids and proteins made by a living cell.

9. Other Compounds in food
Vitamins
Minerals
Water