MUTATION - 2. Nucleoside (base) analogs---molecules that...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
MUTATION: CHANGE IN THE GENETIC MATERIAL A mutation is a change in the base sequence of DNA. This will sometimes cause a change in the  product encoded by that gene. If the gene is an enzyme, the enzyme may become more or less  active because of a change in the amino acid sequence. If the mutation makes the enzyme less  active, this will be harmful or lethal to the cell. If the mutation makes the enzyme more active,  this may benefit the cell.  CHEMICAL MUTAGENS      1. Nitrous acid---at random locations, this chemical reacts with adenine and changes it to a  form that pairs with cytosine instead of thymine. 
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2. Nucleoside (base) analogs---molecules that are structurally similar to the normal nitrogenous bases but do not pair with the normal complementary base. Chemicals such as this are used in some antiviral and antitumor drugs. 3. Some chemical mutagens cause small deletions or insertions, so that frameshift mutations occur. Benzpyrene in smoke and soot and aflatoxin, sometimes present in moldy peanuts, act this way. Acridine dyes, present in Agent Orange and currently used in some antiviral drugs are other examples. Frameshift mutagens tend to cause cancer....
View Full Document

This note was uploaded on 01/23/2012 for the course MCB MCB2010 taught by Professor Smith during the Fall '09 term at Broward College.

Ask a homework question - tutors are online