WHY are nucleotides a good molecule to make DNA out of, while amino acids are a good molecule to make proteins out of?
A COMPLETE and well structured answer will include the following:
How many nucleotides there are? * There are four major nucleotides: A,G,C, and T (Guanine and Adenine and purines, and Cytosine and Thymine are pyrimidines)
How many amino acids there are * There are 20 amino acids
How nucleotides compare to amino acids in terms of diversity of shape and ‘feel’. * nucleotides are not really diverse in shape - there are two basic forms, a double-ringed purine structure and a single-ringed pyrimidine structure. In terms of feel, nucleotides don't have diverse charges - they are primarily negative due to their phosphate groups. Amino acids have a huge variety of shapes and charges. While they have the same properties like a central carbon atom, a carboxyl group, and amino group, and a H atom, they each have extremely different side chains that lead to their sizes and charges. In terms of charges, amino acids can be polar or nonpolar (hydrohphilic/hydrophobic), or acidic and basic.
How the structure and function of DNA compares to the structure and function of proteins. *The structure of DNA is a double helix. The function of DNA is to store and transport genetic information, and have the ability to be replicated (and serve as a template for complementary RNA strands). Proteins have a huge variety of structures that allow them to carry out countless different functions (structural support, enzymatic actions, do the work of the cell, etc.)
Tie it all together:
What is the ‘job’ of DNA? Why are nucleotides good for allowing DNA to carry out its function? What is the job of proteins? How does being built out of amino acids help proteins function?
In what ways are all nucleotides identical? Different?
How many complementary interactions can nucleotides have with one another?