3.16 Describe a DNA molecule as two strands coiled to form a double helix, the strands being linked by a series of paired bases: adenine (A) with thymine (T), and guanine (G) with cytosine (C).
- The diagram below shows a Gene Loci being expanded to display the double helix structure of the DNA:
- The double helix formation has two strands which seem to be parallel with one another.
- This next diagram shows the DNA molecule in greater detail again:
- The two strands that are opposite one another are known as the "Sugar phosphate backbone". No chemical details for this are required. And in the center between these two sections we find a group of mollecules called bases.
- the 4 different types of bases are known as: adenine (A), thymine (T), guanine (G) and cytosine (C).
- These 4 pair to make: Adenine and Thymine; and then Cytosine and Guanine. A with T and G with C.
A ----- T
G ----- C
- These base pairs join/glue one side of the double helix to the other.
- If you draw your attention to just one side of the double helix you find a pattern of the bases which are in a particular order. This is the order which we call the gene.
- So we have a gene which can be defined as the order of the bases, and the number of the bases. With these two things somehow this codes for the construction of a protein in the cytoplasm. And this is what gives us the characteristic.
No comments:
Post a Comment