AS/A Biology | Biomolecules | Notes
  • All of life is mostly composed of the elements C,O,N,H with small amounts of other elements
  • Carbon's property of making chains, provides a backbone to a wide variety of molecules, and is a key feature of chemistry of living things
  • Large molecules are called macromolecules.
  • Biological macromolecules are polymers
  • It is sensible for nature to use polymers due to similarity in manufacturing processes for macromolecules. Else you would need individual different manufacturing processes for each molecule.
  • Main molecules of life: Carbohydrates, lipids proteins and water
  • Molecular biology is the study of molecules that make up the machinery of life, and how these interact to keep the machinery running.


  • Contains only C,H,O
  • fundamental unit: monomers called monosaccharides: Glucose, fructose, galactose
  • dimers, oligomers, polymers of monosaccharides are disaccharides, oligosacharides and polysaccharides
  • alpha and beta glucose structure: []
  • The carbon atoms of glucose are given numbers from 1 to 6 with the carbon in the floating tail getting the number 6
  • The -ose suffix is used to denote that a substance is a carbohydrate.
  • monosaccharides bond together by removal of H2O forming a glycosidic bond
  • glycosidic bond is essentially condensation polymerization
  • glycosidic bond can be broken down by hydrolysis, which happens during digestion

cellulose 3d structure
Cellulose: beta glucose
180 degree rotation
1-6 linkage causes branching
starch is made of amylose and amylopectin
1-4 linkage causes coiling
amylopectin is branched chain
Amylose is straight chain
glycogen is more heavily branched
Iodine test mechanism
Iodine test works for glycogen too
Polysaccharides are not sugars
Pentoses and hexoses can close the ring
The carbon atom number in the tri pent hexose classification
The -ose suffix
Lactose: glucose+galactose
Sucrose: glucose+fructose
Maltose: glucose+glucose
The carbs in the body
Why should carbs be polymerized

Triglycerides most common lipid
Fats vs oils
Saturated unsaturated mono poly unsaturated
Double bonds make it easier to melt unsaturated fatty acids

Protein 3d structure overview:
TEDx talk on proteins. Shows examples of many protein function mechanisms:

How a change in a single amino acid can lead to an organism level change. Sickle cell anemia


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