Chapter 4 Lecture 2 - Genes, Protein Synthesis

Question 1

Genes

Answer 1

Information containing instructions for producing RNA, which will be used to create proteins

Question 2

Base triplet

Answer 2

Sequence of three DNA nucleotides that stand for 1 amino acid

Question 3

Codon

Answer 3

3 base sequence in mRNA (copied from DNA)

Question 4

Anticodon

Answer 4

Sequence of three nucleotides forming unit of genetic code in tRNA, corresponds to a complementary codon in mRNA

Question 5

What first happens when a gene is needed for protein synthesis

Answer 5

Its sequence is copied to mRNA

Question 6

Central Dogma

Answer 6

DNA gets copied to RNA (transcription), RNA is used to create a protein (translation)

Question 7

Enzyme used in transcription

Answer 7

RNA Polymerase

Question 8

How does RNA polymerase know where to start on DNA

Answer 8

Recognition sites

Question 9

Steps of Transcription

Answer 9

1. RNA polymerase opens and unwinds the DNA double helix, knows where to start through recognition sites
2. One strand acts as a template for RNA synthesis
3. Complementary ribonucleotides are added by RNA polymerase in the 3’ to 5’ direction
4. Pre-mRNA is formed
5. Once pre-mRNA is completed, it falls off from template

Question 10

What does the original pre-mRNA include

Answer 10

exons, and introns

Question 11

Alternative splicing

Answer 11

required before RNA leaves nucleus, cuts out introns, pastes exons together into functional mRNA. It can paste these into several orders, forming several proteins from one gene

Question 12

Other post transcriptional modifications

Answer 12

Adding 5’ cap, and Poly (A) tail to 3’ end

Question 13

What is added to the 5’ end of mRNA

Answer 13

5’ cap

Question 14

What is added to the 3’ end of mRNA

Answer 14

Poly (A) tail

Question 15

What is the Poly (A) tail made of

Answer 15

long string of adenines

Question 16

How does the mRNA exit the nucleus

Answer 16

Through nuclear pore complexes