1. The Molecules of Cells Section 2.3

2. Macromolecules Carbohydrates Proteins Lipids Nucleic Acids All organic (contain carbon). Only produced in living things.

3. Carbohydrates Contain C, H, O atoms. Monosaccharides – Immediate energy source – Simple sugars, ex. Glucose used to build polymers Disaccharides – Used by plants to store or transport glucose. – Sucrose, maltose, lactose Polysaccharides – Long polymers made of glucose monomers – Ex. Amylose, cellulose (plant starches), glycogen (animal starch)

4. Lipids Store energy 3 Groups – Triglycerides Animal fats, plant oils – Phospholipids Compose cell’s membranes. – Steroids Act as hormones (estrogen, testosterone, venom, cholesterol.

5. Proteins Amino acids are the monomers of proteins. More than 75% of the dry mass of a cell is protein. Cells produce more than 2,000 proteins 9 Categories, p. 53 – Structural, enzyme, transport, contractile, hormone, antibody, pigment, recognition, toxins

6. Nucleic Acids Composed of nucleotides – Nitrogen base, 5-carbon sugar, phosphate group DNA: deoxyribonucleic acid – Double-stranded – Found in nucleus of eukaryotes, and cytoplasm of prokaryotes – Contains our genetic code RNA: ribonucleic acid – Single-stranded – Found in cytoplasm of cells – Used to make proteins