Chapter 17

Match the following statements with rRNA, mRNA, or tRNA: a. is the smallest type of RNA b. makes up the highest percentage of RNA in the cell c. carries genetic information from the nucleus to the ribosomes

Match the following statements with rRNA, mRNA, or tRNA: a. combines with proteins to form ribosomes b. brings amino acids to the ribosomes for protein synthesis $\mathbf{c}.$ acts as a template for protein synthesis

Endorphins are polypeptides that reduce pain. What is the amino acid order for the following mRNA that codes for a pentapeptide that is an endorphin called leucine enkephalin? $-\mathrm{AUG}-\mathrm{UAC}-\mathrm{GGU}-\mathrm{GGA}-\mathrm{UUU}-\mathrm{CUA}-\mathrm{UAA}-$

What is the anticodon on tRNA for each of the following codons in mRNA? a. $AGC$ b. UAU c. $\mathrm{CCA}$

What is the anticodon on tRNA for each of the following codons in mRNA? a. GUG b. CCC c. GAA

a. If the DNA double helix in salmon contains $28\mathrm{\%}$ adenine, what is the percent of thymine, guanine, and cytosine? b. If the DNA double helix in humans contains $20\mathrm{\%}$ cytosine, what is the percent of guanine, adenine, and thymine?

Why are there no base pairs in DNA between adenine and guanine, or thymine and cytosine?

What is the difference between a DNA virus and a retrovirus?

Consider the following segment of a template strand of DNA: $-\mathrm{ATA}-\mathrm{AGC}-\mathrm{TTC}-\mathrm{GAC}-$ a. What is the mRNA produced for the segment? b. What is the amino acid sequence from the mRNA in part a? c. What is the $\mathrm{mRNA}$ if a mutation changes $\mathrm{AGC}$ to $\mathrm{AAC}$ ? d. What is the amino acid sequence from the mRNA in part $\mathbf{c}$ ? e. What is the mRNA produced if $\mathrm{G}$ is inserted at the beginning of the DNA segment? f. What is the amino acid sequence from the mRNA in part $\mathbf{e}$ ?