U3A1: 2C genes + dna replication

Question 1

genetic code

Answer 1

rules that define how genetic info in nucleotides is transcribed and translated into functional proteins.

Question 2

triplets, codons + amino acids

Answer 2

in dna, three adjacent nucleotides are known as a triplet. a triplet transcribed into mRNA is known as a codon. each codon/triplet codes for a specific amino acid in the polypeptide chain.

Question 3

start + stop codons

Answer 3

start codon AUG codes for a protein (met). stop codons UAA, UAG, UGA, do not code for a specific amino acid.

Question 4

4 properties of the genetic code

Answer 4

• universal
• unambiguous
• degenerate
• non-overlapping

Question 5

the genetic code as universal

Answer 5

most living organisms use the same codons for specific amino acids.

Question 6

the genetic code as unambiguous

Answer 6

each codon is only capable of coding for one specific amino acid.

Question 7

the genetic code as degenerate

Answer 7

each amino acid may be coded for by multiple different individual codons.

Question 8

the genetic code as non-overlapping

Answer 8

each triplet is read independently.

Question 9

regions on the gene

Answer 9

• promoter: binding site for rna polymerase, allowing transcription of the gene. (TATA box)
• introns: non-coding dna that are removed during rna processing. only eukaryotic genes contain introns.
• exons: coding dna that are transcribed + translated into the final protein. found in both pro- and eukaryotes.
• termination sequence: signals for end of transcription
• operator: binding site for repressor proteins that inhibit gene expression in prokaryotic genes.