Next time…

1. Next time… • TEST! • Then a little lecture…

2. Biological Molecules • 4 types of molecule make up all biological systems: • Carbohydrates, Lipids, Proteins, and Nucleic Acids

3. Carbohydrates • Made up of C, H, and O in about this ratio – C1H2O1 • The C-H bonds hold a lot of available energy

4. Monosaccharides • The simplest type of carb • The building blocks of more complicated carbs • MONOMERS and POLYMERS • A very important one is Glucose (others include Fructose, Galactose, etc……) • Fuel for activity • Also can be captured and stored as Glycogen or Fat (short/long term)

5. Polysaccharides • Bigger molecules made of monosaccharides • Structure → function • Energy storage (like starch) or structure (like cellulose) • Cellulose is the most common compound on earth • Plant cell walls • Fiber • We can’t digest it but microbes can (like in termites) • We CAN digest starch…

6. Lipids • Higher density of C-H bonds = more stored E • They don’t dissolve in water • Hydrophobic & Hydrophilic • 3 main types of lipid: • Fats, Sterols, and Phospholipids

7. Fats • Structure: fatty acid head with three CH tails • Saturated fats = tails have as much H as possible • Unsaturated fats = tails have some double bonds • More shared electrons = less bonds to H = kink in tail • Kinks make fats harder to stack = liquid at room temp

8. Fats • Saturated fats linked with heart disease? Maybe, it’s unclear. • http://en.wikipedia.org/wiki/Saturated_fat_and_cardiovascular_disease_controversy • Trans-fats – An artificial process • Turns unsaturated fats into saturated fats • Crisco, vegetable shortening, etc. • Clear link with heart disease • Lowers “good cholesterol”, raises “bad cholesterol”

9. Lipids • Sterols & Phospholipids • Used in building membranes • Sterols also are precursors for cholesterol & sex hormones • Estrogen, Testosterone

10. Lipids • Waxes are another form of lipid • Very water-repellant • Coatings of leaves, bird feathers, beehives, etc...

11. Proteins • They do EVERYTHING • Structure, color, etc... • They also DO everything that gets done in organisms – Enzymes • Every protein built from the same 20 amino acids • Linked end to end in a chain – different order = different protein • Those are built from CHO, like the others, but also N

12. Proteins • Structure → Function • Primary – the order of AAs • Secondary – basic 3D structure • Tertiary – More complicated 3D structure • Quaternary – Proteins linked to other proteins

13. Proteins • When a protein loses structure (usually because of the environment) – DENATURATION • Some proteins are bonded to carbohydrates – glycoproteins • Some are bonded to lipids – lipoproteins

14. Enzymes • Once again Structure → Function • Active site is where the action happens • Substrate modified • Bonds formed/broken, energy used/released • EXAMPLE: Salivary amylase breaks bonds between glucose molecules in starch

15. Nucleic Acids • They store information • Monomers = nucleotides, arranged in a long chain • 2 types: DNA and RNA • Both store information in the order of the nucleotides • Sugar-phosphate backbone is attached to Nitrogenous base • That’s where the info is stored

16. DNA • Double helix • Two strands of mirrored information • A-T and G-C • Human genome is about 3billion bp

17. RNA • Generally not double stranded • The sugar-phosphate backbone is different (+ an O) • Acts as the middleman between DNA and protein • Also has other functions in the cell