1. Chapter 3: Molecule of Biology

2. Atoms, molecules and compounds: Atoms: fundamental units of the physical world

3. 4 important organic molecules: Proteins Carbohydrates Lipids Nucleic acids

4. #1: Proteins: Polymers of amino acids:

5. #2: Carbohydrates: Saccharide: Monosaccaride: – Formula: C n H 2n O n – Fructose – Glucose – Differ by location of double bond – same molecular formula

6. How are carbohydrates packed? Disaccarides – 2 monosaccharides Polysaccharides – 3+ monosaccharides Glycogen (animals used to store glucose) Starch (plants use to store glucose) Cellulose (structural for plant cell walls)

7. #3: Lipids: Lipids are fats! Monomer: hydrocarbon Note: hydrocarbons hydrophobic (‘water-fearing’) 3 most common forms in which lipids are found in body: – Triglycerides – Phospholipids – cholesterol

8. Triglycerides

9. Phospholipids Look similar to triglycerides One fatty acid is replaced with phosphate group Phosphate group is hydrophilic (‘water loving’) – “polar”

10. Cholesterol: Hydrocarbons form ring Found in animal cells

11. #4: Nucleic acid Acidic macromolecules that are found in nucleus of cell DNA (deoxyribonucleic acid) RNA (ribonucleic acid) Nucleotide: – Sugar – Phosphate – Base

12. Types of nucleotide bases:

13. DNA: Double stranded Sugar phosphate portions of nucleoid chains form sides of ladder Bases bond to each other Ladder twists to form double helix Has A, T, C, G

14. On nucleotide base pairing: Adenine and thymine bind to each other A=T Cytosine and guanine bind to each other CΞG

15. RNA: RNA is single stranded Uses ribose sugar Uses uracil instead of thymidine – A, C, U, G

16. RNA vs. DNA