The hereditary information of an organism is stored in the DNA in the
form of a code. This code consists of four building blocks or bases (A
for Adenine, C for Cytosine, G for Guanine, T for Thymine). These bases
follow each other in a certain sequence, e.g. ...AGTCGTAATTGGCCCCAATTGCAAAAA....
If such a sequence contains the information for a single protein, it is
called a gene.
The DNA-backbone consists of sugars (deoxyribose) and
phosphates. Each sugar has a base bonded to it: either adenine, guanine, cytosine
or thymine. DNA
occurs as a double helix with the two chain held together by
hydrogen bonds between the bases, the so-called base pairs.
Adenine is always paired with thymine, and guanine with cytosine.
Fill in the following names in the figure below: adenine, thymine, cytosine, guanine, uracil, phosphate, deoxyribose, hydrogen bond, backbone, and bases. Answer
A piece of DNA contains 33% guanine. What are the percentages of adenine, cytosine, and thymine in that piece of DNA? Answer
In RNA deoxiribose is replaced by ribose and thymine by the base uracil. RNA is usually found as a single chain. However, this chain can fold by making hydrogen bonds (base pairs) with itself, thus forming a typical 3D structure.
Name two types of RNA that are known for their typical structure. Answer
The
DNA sequence forms the basis for proteins. Enzymes make an RNA-copy of
one of the chains in the double helix. This messenger RNA
(mRNA) contains the code that dictates the amino acid sequence of the
protein product. The actual synthesis of proteins is done on the
ribosomes.
TACCATCCGTTCATGATCIf you understood all the questions, you should have a firm grasp of the basics needed to use this site. You can now continue to a short introduction in the field of bioinformatics.
