How To Apply Genetic Codes

How to apply genetic codes Predicting the sequence of amino acids from a sequence of codons in RNA

DNA has the genetic code • The code is for the sequence of amino acids • The initial RNA transcript is copied from DNA. • This transcript is made of exons and introns

EXONS and INTRONS • Exons: sequences of nucleotides that carry useful information for protein synthesis • Introns: Sequences of nucleotides that do not carrry useful information • Before leaving the nucleus; introns are removed and exons are spliced together • This final transcript is mRNA

Mutations • May or may not affect the expression of the gene or the sequence of amino acids in the encoded protein • Permanent changes in the sequence of nitrogenous bases • Occurs when base pairs are matched incorrectly (A with C or G with T) • Can (it is rare) improve the product

Somatic cells • Somatic cells make up the body “soma”compose organisms • Blood, bone, organs, connective tissues • Mutations that occur in somatic cells are often not detected because they cannot be passed on to offspring • May give rise to cancer

Genetic disease • Mutations in germ cells • Create functionally different proteins • Tay-Sachs disease • Cystic Fibrosis • Sickle cell anemia • Duchenne Muscular dystrophy

More about mutations • SAD- is often treated with "light therapy," where a SAD patient spends time each morning before bright lights in an effort to trick the brain into believing that the days are not so short or dark. • A new study indicates that SAD may be linked to a genetic mutation in the eye that makes a SAD patient less sensitive to light. • Journal article