Online A level Biology Tutor

View Original

A-level Biological Molecules - 11 basic points to help you learn

1. 99% of life is Carbon, Hydrogen, Oxygen and Nitrogen (and a bit of Phosphate)

2. Mono is one, Di (and Bi) is two, Tri is three, oligo is a few, poly is many.

3. Anything ending in -ose is a sugar, -ol is a lipid. - ase is an enzyme and all enzymes are proteins

4. Beta glucose is only in Cellulose - everything else is Alpha glucose

5. A condensation reaction makes water and joins two monomers together - glycosidic bond is a condensation reaction

6. A hydrolysis reaction breaks a bond (lysis means split) - with the addition of water (hydro)

7. A Glycosidic bond joins 2 monosaccarides together 

8. A peptide bond joins 2 amino acids together (many-poly, by peptide bonds...=polypeptide)

9. A lipid is made from a glycerol joined by an ester bond to 3 (tri) fatty acids - hence triglyceride

10. Carbohydrates and lipids are just C,H,O. Amino acids are C,H,O,N (ok, and a bit of Sulphur with 2 of the R groups), Nucleic acids (DNA, RNA, ATP) have C,H,O,N,P. Phospholipids are C,H,O,P.

11. Large or non-polar molecules are insoluble in water hence Starch, Glycogen and Fats are osmotically inactive which means they are good energy storage molecules