Bacterial Transformation

Question 1

A cluster of adjacent structural genes in bacteria controlled by a single promoter and operating as a coordinated unit

Answer 1

Operon

Question 2

Genes that produce proteins that contribute to the structure or functioning of an organism

Answer 2

Structural Genes

Question 3

Genes that produce proteins that control the activity of other genes

Answer 3

Regulator Genes

Question 4

Outline the process in which trp is produced when the levels are low in a prokaryotic cell

Answer 4

• RNA Polymerase transcribes the repressor protein
• No free Tryptophan is available to bind to the repressor protein
• The repressor protein is unable to bind to the operator region
• RNA Polymerase is able to move past the operator region and transcribe the structural genes

Question 5

Under what conditions would a prokaryotic cell inhibit the trp operon

Answer 5

• If trp levels are high within the cell

Question 6

Explain the mechanisms by which the trp operon is regulated

Answer 6

• RNA Polymerase must bind to the promoter region
• The repressor protein will undergo a conformational change in shape if bound to trp enabling it to bind to the operator
• Structural genes contain start and stop codons

Question 7

Explain how the trp operon may be inhibited during transcription of the structural genes

Answer 7

• Attenuation
• A ribosome is signaled to prematurely start translation of the mRNA
• This results in the formation of a hairpin loop
• The movement of the Ribosome and the hairpin loop cause the RNA Polymerase to detach from the Structural Genes and stop transcription

Question 8

Any cells or organisms without a membrane-bound nucleus

Answer 8

Prokaryotes

Question 9

A protein produced by a regulatory gene that can bind to DNA and prevent transcription

Answer 9

Repressor Protein

Question 10

A collection of adjacent genes in bacteria that code for the enzymes needed in the production of tryptophan

Answer 10

trp Operon