Biology · Form and function

B1.1 — Carbohydrates and lipids

Biology · SL / HL · syllabus-mapped notes

1. B1.1.1

   Chemical properties of a carbon atom allowing for the formation of diverse compounds upon which life is based

   Explain how carbon's four covalent bonds allow chains, branches and rings, and give examples of each.

2. B1.1.2

   Production of macromolecules by condensation reactions that link monomers to form a polymer

   Explain condensation, and name examples of polysaccharides, polypeptides and nucleic acids.

3. B1.1.3

   Digestion of polymers into monomers by hydrolysis reactions

   Explain hydrolysis, including how the split water supplies the -H and -OH the monomers take up.

4. B1.1.4

   Form and function of monosaccharides

   Recognize pentoses and hexoses from ring diagrams, and link glucose's four properties to how it is used.

5. B1.1.5

   Polysaccharides as energy storage compounds

   Explain why starch and glycogen suit energy storage: compact, insoluble, and easy to build up or mobilize.

6. B1.1.6

   Structure of cellulose related to its function as a structural polysaccharide in plants

   Explain how alternating beta-glucose gives straight chains, bundled and cross-linked by hydrogen bonds.

7. B1.1.7

   Role of glycoproteins in cell–cell recognition

   Explain how glycoproteins allow cell-cell recognition, using ABO antigens.

8. B1.1.8

   Hydrophobic properties of lipids

   Define lipids by their solubility, and name the four classes.

9. B1.1.9

   Formation of triglycerides and phospholipids by condensation reactions

   Explain how condensation builds a triglyceride and a phospholipid from glycerol.

10. B1.1.10

    Difference between saturated, monounsaturated and polyunsaturated fatty acids

    Distinguish saturated, monounsaturated and polyunsaturated by C=C bonds, and link this to melting point.

11. B1.1.11

    Triglycerides in adipose tissues for energy storage and thermal insulation

    Explain why triglycerides suit long-term storage, and relate their insulating role to habitat.

12. B1.1.12

    Formation of phospholipid bilayers as a consequence of the hydrophobic and hydrophilic regions

    Explain why amphipathic phospholipids form bilayers on their own.

13. B1.1.13

    Ability of non-polar steroids to pass through the phospholipid bilayer

    Identify a steroid from a diagram, and explain why non-polar steroids cross the bilayer.