| Question |
Answer |
| What is a codon? |
A set of three nucleotides |
| How many different possible trinucleotides can be formed? |
64 |
| Which way, wrt 3' and 5' ends, do codons read? |
5' to 3' |
| What is the second letter for all AAs with a charged side chain? |
A |
| Which 2 letters are the most important in a codon? |
ONLY first 2 |
| Which AAs have the most codons? |
Arg, Leu, Ser |
| Which AAs have single codons? |
Trp and Met |
| Which codons are stop codons? |
UGA, UAG, UAA |
| What is the initiator codon? |
AUG |
| Codons with what letter will have a hydrophobic side chain? |
U |
| What are anticodons? |
the codon match on the tRNA during protein synthesis |
| What is the wobble hypothesis? |
the first base of the anticodon does not follow stringent pairing with the last base of the codon |
| What is meant by 5'-UTR? |
the 5'-untranslated region; usually 30 - 100 nucleotides in before the initiation of translation |
| What is meant by 3'-UTR? |
3'-untranslated region; the region downstream from the stop codon on the mRNA |
| What is the term reading frame? |
the nucleotide sequence being translated |
| How many possible reading frames are there in a given region of DNA? |
6 |
| What is ORF? |
open reading frame; series of codons that lacks a stop codon |
| What is the frequency of having a stop codon in a random sequence of codons? |
1/20 |
| What is a point mutation? What are the two kinds? |
a single base pair change; transition A to G; transversion purine to pyrimidine |
| What is a silent mutation? |
3rd place change in a codon; typically has no effect on phenotype |
| Describe a Missense mutation |
point mutation, changes the meaning of a codon word and thus changes a single AA |
| Describe a nonsense mutation |
stop codon in a coding region; generally serious mutations |
| Insertion mutations |
lead to frame shift mutations downstream; serious mutations |
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Biology Lab Midterm
