M3 The functional unit of information on the chromosome is the gene.

Student Outcome: M3.1

Know that a gene consists of a unique sequence of bases that code for a polypeptide or an RNA molecule.

The information that is necessary to control the cell is found in the structure of DNA called the genetic code. This is the sequence of base pairs that are arranged to code for a particular protein or RNA molecule. This section of the DNA is called the gene. The gene then, is the functional unit of the chromosome.

RNA

RNA is the other type of nucleic acid,

• RNA contains the base Uracil instead of Thymine
• RNA contains a different type of sugar in the sugar-phosphate backbone (ribose instead of deoxyribose)
• RNA is a single stranded molecule (it does not form a double helix).
• RNA is shorter than DNA.
• There are 3 types: messenger-RNA (mRNA), transfer RNA (tRNA) & Ribosomal RNA (rRNA)

Student Outcome: M3.2 (See also M 4.1)

Describe how three bases, called a codon in mRNA, code for one amino acid.

Check out this video on translation. The initial bit shows how the three bases code for one amino acid.

Here is another less complex and more graphical version: