BIOL 112 Lecture Notes - Lecture 21: Ribozyme, Telomerase, Lipid Bilayer

• School: McGill University
• Department: Biology
• Course: BIOL 112
• Professor: Lucy- Ann Joseph

Document Summary

Cell can regulate the turning on of a gene by interact with the enzyme polymerase: e. g. the gene for enzyme lactase is only turned on when lactose is present. This is regulated by inducer. (posiive feedback: negaive feedback turns a gene of. Tetraploid and cell size: ploid means how many sets of genome is present in the cell, tetraploids have 4 sets of complete genome (more dna, tetraploids tend to be big (compared to the same species. Large spaces between genes; along one dna strand, the parts where it gets encoded for proteins have spaces between them: the coding parts of the gene exons, noncoding sequences introns, exons are interrupted by introns. Splicing cuts out exons and join those together. Replicaion of dna makes the dna shorter every ime, unil the cell cycle checkpoint prevent further division). Made by enzyme telomerase: most cells do not express telomerase.