BIOL 142 Lecture Notes - Lecture 1: Theodor Boveri, Walter Sutton, Stop Codon
Tuesday, January 23, 2018
BIOL142
•What makes us unique? Different versions of genes#
•Instructions are not always available - nucleus is the first line of defense#
•Can instructions be changed - mutations#
What is a gene?#
•Gene: a unit of heredity that is transferred from a parent to offspring and is held to
determine some characteristic of the offspring#
•Technical definition: a sequence if nucleotides forming a part of a chromosome, the
order of which determines the order of monomers in a polypeptide or nucleic acid
molecule which a cell may synthesize#
•What does a gene need to function?#
•Carry information/code#
•Regulation - on/off switch#
•Withstand errors#
•Mendel - alleles are associated with specific traits which are transmitted to offspring#
•Theodor Boveri and Walter Sutton - chromosomes occur in matched pairs which
separate during meiosis. #
•Watson&Crick&Rosalin Franklin - used previous an new observations to model
secondary structures of double stranded DNA#
•Post-transcriptional control: mRNAs can be modified and/or degraded#
•mRNA is read from 5’-3’ for translation#
•Start codon = AUG#
•Stop codon = UGA, UAA, UAG#
•Redundancy - the code can withstand errors
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