DNA, RNA, genes

Question 1

deoxynucleotide triphosphates [dNTPs]

Answer 1

the nucleoside triphosphates containing deoxyribose. they are the building blocks of DNA, and they lose 2 of the phosphate groups when incorporated into DNA during repliation

Question 2

DNA gyrase

Answer 2

eukaryotic DNA replication doesnt require DNA gyrase. DNA gyrase inhibitors can therefore be used as anti-bacterial theraputics

Question 3

topoisomerase

Answer 3

enzymes in eukaryotic replication, participates in the winding/ unwinding of DNA

Question 4

DNA helicase

Answer 4

unwinds the DNA strand

Question 5

DNA polymerase

Answer 5

joind the shorter strands in the 3’ to 5’ direction

Question 6

DNA ligase

Answer 6

joins the duplicated strands by phosphodiester bonds

Question 7

eukaryotic 5’ cap

Answer 7

added post-transcriptionally, a 7-methylguanosine with an unusual 5’-5’ triphosphate linkage

Question 8

eukaryotic mRNA; coding region

Answer 8

• coding region of a gene is the open reading frame [ORF]
• translation occurs using codons
• the correct reading frame is defined by the AUG start codon
• ends when a stop codon is reached [UAG, UAA, UGA]

Question 9

Eukaryotic mRNA; 3’ end

Answer 9

• transcription is terminated by cleavage of pre-mRNA
• the poly[A] tail is added post transcriptionally [no DNA template]
• tail addition requires a concensus sequence [AAUAAA]
• The tail is required for efficient transport from the nucleus to the cytoplasm, and also regulates mRNA stability and translation