BISC 202 Chapter Notes - Chapter 13: Ribonucleotide, Start Codon, Ribosomal Rna

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blackscorpion252

28 Nov 2018

School

Simon Fraser University

Department

Biological Sciences

Course

BISC 202

Professor

Michael Hart

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Document Summary

13. 1 reading notes: the genetic code uses ribonucleotide bases as letters . General features characterizing the genetic code: written in linear form letters = bases in ribonucleotides that compose mrna molecules, word = three ribonucleotide letters (triplet code), each group of three ribonucleotides is called a codon. A single coding dictionary is used by almost all viruses, bacteria, archaea and eukaryotes. 13. 2: early studies established the basic operational patterns of the code. Ribosomal rna is extremely unstable and since the intermediate that transfers genetic information from dna to proteins is extremely unstable, the intermediate must be mrna. Gain or loss of 1 or 2 nucleotides causes a frameshift, but the gain or loss of three nucleotides simply re-establishes the reading frame. 13. 3: studies by nirenberg, matthaei, and others led to deciphering of the code. Nirenberg and matthaei were the first to link specific coding sequences to specific amino acids.

Related Questions

The genetic code in our world is a triplet code using combinations of four letters (A,U,G,C). All code words (codons) are the same size, three bases long. Proteins in our world are build using combinations of 20 different subunits (amino acids). In class, we argied tjat imder the conditions in our world (only four differebt letters in mRNA to code for 20 different amino acids in proteins) a triplet code is the smallest possible code that could be sued. A) list the other properties of our genetic code. C) what do we mean by the term degenerate code? Cam a doutblet code also be a degenerate code? (If yes, under what circumstances? If no, why not?) D) Does degeneracy in its genetic code represent 1) an advantage; 2) a disadvantage or 3) both and advantage and a disadvantage or 4) neither an advantage nor a disadvantage to an organism?

Fill in the blank. Elongation during translation does NOT involve ____________.

Question 16 options:

	the translation of codons according to the genetic code
	the formation of bonds catalyzed by the ribosome
	complementary base pairing between RNA molecules
	amino acids being linked together in a polypeptide
	reading the DNA template 3' to 5'

For a given gene, what establishes the reading frame for translation?

Question 17 options:

	the location of the enhancer relative to the gene
	the first three nucleotides at the 5' end of the mRNA
	the first three nucleotides at the 3' end of the mRNA
	the start codon in the mRNA
	the location of the promoter relative to the gene

Which of the following is the LEAST likely direct consequence of a substitution mutation?

Question 18 options:

	changing the length of a protein coded for by a gene
	changing one amino acid in a protein
	creating a stop codon
	eliminating a start codon
	changing the length of the DNA molecule containing a gene

Suppose that the pre-mRNA transcript from a eukaryotic gene is 30,000 nucleotides long, and the gene codes for a sequence of 300 amino acids. What is the best explanation for the relationship between these numbers?

Question 19 options:

	only the first 900 nucleotides of the pre-mRNA transcript are translated
	it takes 100 nucleotides to specify a single amino acid
	300 of the nucleotides in the transcript are important, and the rest are "junk"
	only the last 900 nucleotides of the pre-mRNA transcript are translated
	large portions of pre-mRNA transcripts are cut out during RNA processing

Suppose an individual is born into a population with a novel mutation. Is the new mutation an evolutionary change, and why?

Question 20 options:

	no, because it is not a big enough change to count
	yes, because new mutations are always adaptive
	yes, because the appearance of a new genetic variant is a genetic change in a population
	no, because not enough individuals have the mutation for it to matter
	no, because most mutations are not adaptive

1. _________________________ is the name of the process that produces proteins using RNA molecules.

a.Transcription

b Translation

c. Replication

d. Mutagenesis

2. The peptide bonding site on the ribosome:

a. A site

b. P site

c. E site

d. D site

3. The name given to the bond formed between two amino acids.

a. Hydrogen bond

b. Double bond

c. Peptide bond

d. Negative bond

4. __________________________ is the movement of the mRNA molecule on the ribosome to open up the A-site for the new incoming amino acid.

a. Transformation

b. Mutation

c. Translocation

d. Initiation

5. What does the term semi-conservative mean.

a. Replication of RNA is semi-conservative, each new strand consists of one old strand of RNA and one new strand of RNA.

b. Replication of DNA is semi-conservative, each new strand consists of one old strand of DNA and one new strand of DNA.

c. Replication of DNA is semi-conservative, each new strand consists of new strands of nucleotides.

d. Transcription of RNA is semi conservative.

6. This molecule functions during protein synthesis to recognize the codon and bring the proper amino acid back to the ribosome for translation.

a. mRNA

b. tRNA

c. rRNA

d. DNA polymerase

7. What is meant by the base-pairing rule.

a. Bases on a single strand of DNA are always found as pairs

b. Adenine always base pairs with guanine; cytosine with thymine

c. Adenine always base pairs with thymine; cytosine with guanine

d. Bases on a single strand of RNA are found in pair.

8. In this step of protein synthesis, amino acids are added to a growing polypeptide chain.

a. Initiation.

b. Elongation.

c. Termination.

d. Transpiration.

9. Three complementary bases found in a mRNA are called ____________________.

a. Anti-codon.

b. Triplet.

c. Doublet.

d. Codons.

10. Which statement best describes the job or function of the messenger RNA.

a. Carries the map of the gene sequence in the form of codons to the cytoplasm

for translation of the protein.

b. It transfers amino acids to the ribosome for protein synthesis.

c. It forms the ribosomes.

d. It helps replicate DNA.

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BISC 202 Chapter Notes - Chapter 13: Ribonucleotide, Start Codon, Ribosomal Rna

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