Biology B3 Part 3

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  • Created by: Sam
  • Created on: 17-04-12 17:19

Based on Edexcel Textbook

pg 26-27 Genomics

DNA consists of thousands of 'building blocks' called nucleotides. Each neucleotide has a base making up part of its structure-adenine(A),thymine(T),guanine(G)or cytosine(C). A gene is a section of DNA. Each gene has a different order of bases making up our genetic code. The code is a set of instructions for the production of proteins. Each set of three bases codes for one of the amino acids that makes up a protein they can then be arranged in the right order.

A genome is all of the DNA in every cell of an organism. Genomics is the science of working out the gentic code and order of bases. In1986 Scientists in the UK and USA set up the human genome project to sequence all 3.1 billion nucleotides that make up the DNA of the human genome.

It was done by taking the cells of volunteers and breaking up the chromosomes of the cell to access the DNA. Thousands of copies were made so there would be enough to work with. The DNA was then put in a machine called a sequencer to find the most probable order of bases.

Bioinformatics aims to go one step further and find which genes code for which proteins and show where each is made within a cell.

pg 28-29 Genomic Medicine

Responses to drugs depend on DNA because except for identical twins all people have slightly different DNA. This explains adverse drug reactions. Finance and reason mean that drug companies can only produce one drug to treat a disease. Combining Genomics with Pharmacology could be the answer making drugs specific to DNA make-up. This is called Pharmacogenomics. The use today is limited.

Salbutamol is a drug to treat asthma but different muscle make-up means that in some people it is unaffective. Analysing genes means these people can be quickly identified and given an alternative drug.

In some people enzymes in the…


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