BI226 Lecture Notes - Lecture 3: Essential Amino Acid, Albinism, Auxotrophy
Document Summary
Genes on dna are transcribed to rna which can then be translated to protein the central dogma of biology. Garrod (1902) proposed that mutations prevent a gene from producing an enzyme required for a specific biochemical reaction. He showed that alkaptonuria results from homogentisic acid (ha) in the urine. He reasoned that alkaptonuria patients lacked an enzyme in this pathway. Phenylketonuria (pku) is commonly caused by a mutation on chromosome 12 in the. Phenylketonuria (pku) is commonly caused by a mutation on chromosome 12 in the phenylalanine hydrolase gene, preventing the conversion of phenylalanine into tyrosine. Phenylalanine is an essential amino acid in excess harmful- normally converted to tyrosine. excess phenylalanine affects the cns, causing mental retardation, slow growth, and early death. Others result from inability to make tyrosine; these include fair skin, blue eyes (even with brown-eye genes) and low adrenaline levels.
