The Biochemical Basis of Life

In This A-Level Biology Lesson “The biochemical basis of life” you will be introduced to phylogenetic trees, the idea that biochemical similarities support the theory of evolution and the 4 biological molecules you must know.

What is the name of the diagram used to depict shared ancestry and evolutionary relationships?

Shared common ancestry can be depicted by means of a phylogenetic tree - a diagram that represents the relatedness and evolutionary history of a given species. The branch points on the diagram relate to a shared common ancestor between species. Despite the variety of life on Earth being extensive, ALL organisms share the same basic biochemistry. 

Specifically, Carbon-based compounds such as: -

- Nucleotides, which form DNA and RNA

- Amino Acids, which form Polypeptides (proteins)

- Monosaccharides, which form Polysaccharides.

​The 4 Biological Molecules you have to know are: -

​1. Nucleic acids: - (DNA & RNA) Which are made up from Nucleotides.

2. Proteins (polypeptides): - Which are made up from Amino Acids.

3. Carbohydrates: Which are made up from Monosaccharides.

4. Lipids: Which are NOT polymers, since they are made up from Glycerol + Fatty Acids (not repeating monomers!)