BIOLOGY 1A03 Lecture Notes - Lecture 3: Reading Frame, Methionine, Smn1

53 views2 pages

scarletspider676

21 Apr 2016

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

doinhumolalala and 39849 others unlocked

BIOLOGY 1A03 Full Course Notes

Verified Note

9 documents

Document Summary

Open reading frame is the part of a reading frame that has the potential to code for a protein/peptide. Start at aug and stops at stop codon, with a continuous stretch of codons. In any sequence, we have 2 putative (coding) strands. Methionine (aug) sets start for reading frame and stop codon stops it. Insertion of nucleotide early is bad better after in case you reach a stop codon early, making the protein non-functional; little effect in end. Insertion/deletion in an intron has no effect bc its going to be spliced so it wont disrupt the reading frame. Insertion/deletion of 3 nucleotides (full codon) usually has no effect depending if the function of an amino acid is important and it gets removed or shifted, creating a diff amino acid (e. g. recognition) Rna could be jumping to different part of dna or rna could be being spliced! Splicing occurs at 5" end of intron first.

Related Questions

Part B

Think about the DNA coding sequence of a gene. If an A were swapped for a T, what kind of mutation could it cause and why?

a) It could cause a frameshift nonsense or frameshift missense mutation because it would change the reading frame of the codon triplet.

b) It could cause a silent, missense, or nonsense mutation because those are the types that can be caused by a nucleotide-pair substitution like this one.

c) It could cause a nonsense mutation because the sequence would no longer be the same, so the protein would be shorter and non-functional.

d) It could cause a silent mutation because A and T are complementary to each other so it is not really a substitution mutation.

Part C

Why is a frameshift missense mutation more likely to have a severe effect on phenotype than a nucleotide-pair substitution missense mutation in the same protein?

a) A substitution missense mutation causes the protein to be shorter and thus non-functional.

b) A frameshift missense will cause the codons to be out of order, but a substitution missense does not change the order of the codons.

c) A frameshift missense mutation will cause an early Stop codon, but a substitution missense might be silent.

d) A substitution missense affects only one codon, but a frameshift missense affects all codons downstream of the frameshift.

Part D

Which of the following sequences shows a frameshift mutation compared to the wild-type mRNA sequence?

a) wild-type	5â-AUGCAUACAUUGGAGUGA-3â
mutant	5â-AUGCAUACAGAGUGA-3â

b) wild-type	5â-AUGCAUACAUUGGAGUGA-3â
mutant	5â-AUGCAUACGUUGGAGUGA-3â

c) wild-type	5â-AUGCAUACAUUGGAGUGA-3â
mutant	5â-AUGCAUACAUCUGGAGUGA-3â

d) wild-type	5â-AUGCAUACAUUGGAGUGA-3â
mutant	5â-AUGCAUGUGACAUUGGAGUGA-3â

Part F

Suppose that the triplet of nucleotides indicated in bold (AGC) spans two codons, that is, CTA and GCC. If the triplet AGC were deleted from this DNA coding sequence, what effect would it have on the resulting protein?

5â-ATGCTAGCCTATCGTAAC-3â

a) The two flanking codons would be altered, but the rest of the amino acid sequence would be the same because there would be no frameshift.

b) The entire amino acid sequence would be altered due to the frameshift.

c) All of the amino acids after the deletion would be altered due to the frameshift.

d) All of the amino acids up to the deletion would be altered due to the frameshift.

mauvetrout554

BIOLOGY 1A03 Lecture Notes - Lecture 3: Reading Frame, Methionine, Smn1

BIOLOGY 1A03 Full Course Notes

Document Summary

Get access

Related Documents

BIOLOGY 1A03 Lecture Notes - Lecture 7: Open Reading Frame, Sydney Brenner, Marshall Warren Nirenberg

BIOLOGY 1A03 Study Guide - Final Guide: Rna Tie Club, Rna World, Start Codon

BIOLOGY 1A03 Lecture Notes - Lecture 3: George Gamow, Start Codon, Genetic Code

Related Questions