Gene Expression and the Impact of DNA Mutations

University:
York University
Course:
BIOL 107 | Introduction to Cell Biology
Academic year:

2024
Views:

214

Pages:

2
Author:

Ciara T.

Gene Expression Gene Sequence of nucleotides that code for one or biological product (proteins, non-proteins such as functional more +RNA, RNA) Gene Expression •Synthesis of the biological product (eg protein) When synthesized, the protein encoded by the gene is "expressed" •Converting info in DNA into functioning molecules within the cell DNA (information storage) Predict AA Sequence (a) Using the genetic code to predict an amino acid sequence SATGGCCAATGACTTT CAA TAA 3' TACCGGTTA CTGAAAGTT ATTS The DNA sequence... ...would be transcribed as 5' AUGGCCAAUGACUUUCAA UAA ...and translated as Met Ala Asn Asp Phe Glu (stop) Read from 5' 3' Start with start codon AUG Always sequences of 3 nucleotide End with end codon UAA, UAG, or UG, A How can mutations at the DNA level affect protein resulting from translation? Mutations Any permanent change in organism's DNA Change genotype which can cause affect on phenotype • A single base change is a point mutation Point Mutation The red dog bit the tan zat Can result from errors in DNA replication Types: The red dog bit The tau cat Silent } The awd hog bit the tan catatan Base-pair substitutions The red dig hit the ta ost. Missense The red die ghi tth wha nos t • Nonsense The red ogh itt het anc at Base Inserted } Frameshift mutations Sickle cells Base removed Causes change in AA sequence of the protein = missense • No change silent Change AA to similar AA causing no phenotypic change = Early termination to AA sequence nonsense neutral