4: Gene Functions Flashcards
What type of mutation is alkaptonuria?
Recessive
What metabolic error causes alkaptonuria?
Inability to metabolize homogentisc acid.
What was the first evidence of the specific relationship between genes and enzymes?
Alkaptonuria
What is the phenotype of alkaptonuria?
Urine blackening and arthritis
How did beadle and tatum devise the one gene one enzyme hypothesis?
Using neurospora ascospore auxotrophs
What metabolic pathway did beadle and tatum deduce?
Methionine biosynthesis
What metabolic error causes pku?
Inability to convert phenylalanine into tyrosine. Defective phenylalanine hydrolase.
Symptoms of pku:
Mental retardation, slow growth, early death (pleiotropic effects)
How do you screen for pku?
The guthrie test
What metabolic error causes albinism?
Defective tyrosinase enzyme. So no melanin.
What kind of mutation causes albinism?
Autosomal recessive
What metabolic error causes lesch nyhan?
Defective hgprt gene
What kind of mutation causes lesch nyhan?
Sex-linked recessive
What kind of mutation causes tay sachs?
Autosomal recessive
What metabolic error causes tay sachs?
Lysosomal storage disorder. No hexA, which cleaves from brain ganglioside.
