a.) 5' -GUAGCCUACCCAUAGG- 3'
b.) No peptides could be made from this sequence of RNA alone because of the absence of a start codon, AUG. If the other strand of DNA was transcribed, then the resulting peptides would be different than the peptides that would potentially be transcribed from the complementary strand mentioned in part a.
For example, if the sequence of strand A was 5'-AAAGGGCCC-3' then the sequence of the complementary strand, strand B, would be 5'-TTTCCCGGG-3'. The mRNA transcribed from strand A would be 5'-UUUCCCGGG-3' and the resulting peptide would be Phe-Pro-Gly. The mRNA transcribed from strand B would be 5'-AAAGGGCCC-3' and the resulting peptide would be Lys-Gly-Pro. The resulting peptides are different.
c.) Val-Ala-Tyr-Pro. After tRNA^Ala left the ribosome tRNA^Tyr would remain in the P site and tRNA^Pro would be next in line to add its amino acid to the growing polypeptide chain. When alanine forms a peptide bond it's between the new amino acid's (tyrosine's) amino group in the A site and the carboxyl group of alanine. Alanine would be on the end of the growing polypeptide chain located in the P site. No bonds are broken in the formation of peptide bonds but a water molecule is lost due to dehydration synthesis. After the peptide bond is formed between alanine and tyrosine, the growing chain is transfered to tRNA^Tyr in the A site. Then both tRNA^Ala and tRNA^Tyr shift so that tRNA^Ala is in the E site and tRNA^Tyr is in the P site. tRNA^Ala is released and another tRNA will attach to the A site to continue elongation.
d.) The Segement of DNA mentioned in part a could not have originated from the beginning of the strand because there is no start codon. It's possible that the sequence came from the middle because no matter what reading frame is used there is no start codon. However there is a stop codon close to the 3' end, UAG. It's also possible that it originated from the end depending upon what nucleotides, if any, follow the segement (if they were to form a stop codon.)
2.
a.) 35S-methionine is used as a marker. It works by binding to proteins so that seperation can be detected..
b.) Electrophoresis is an analytical tool used to study the properties of a single charged species and as a seperation technique. The sample being studied is usually run in a support matrix, agarose and polyacrylamide are most commonly used. Support matrices are porous and can therefore seperate molecules by size. Polyacrylamide has a smaller gel pore size than agarose and is used for seperating most protiens and oligonucleotides.
c.) No. Synthesis slows as the protein lengthens.
d.) about 35 amino acids/ min