Lecture 6

Question 1

What happens during transcription

Answer 1

It the 1st part when a gene is transcribed into mRNA which is then translated into a protien

Question 2

What are proteins

Answer 2

Polypeptide chains of amino acids

Question 3

What are genes

Answer 3

They are short sequences of DNA that contain genetic instructions to produce an RNA molecule and/or protein

Question 4

What is genetic code

Answer 4

It refers to a triplet sequence of ribonucleotides that codes for a specific amino acid

Question 5

Examples of proteins

Answer 5

Fibrous proteins
Digestive enzymes
Metabolic enzymes
Immune system

Question 6

What is transcription

Answer 6

Portion of DNA nucleotide sequence copied into RNA nucleotide sequence. Occurs in the nucleus for eukaryotic cells and the cytoplasm of prokaryotic cells

Question 7

What is translation

Answer 7

Synthesis of polypeptide under direction of RNA. Occurs in the cytoplasm of all cells

Question 8

Transcription and translation in eukaryotes

Answer 8

1) DNA protected in nucleus therefore transcription occurs in the nucleus
2) But mRNA most exit the nucleus to go to the cytoplasm for translation
3) DNA contains non-coding DNA (introns) which must be cut out of DNA between the 2 processes therefore mRNA processing required

Question 9

Transcription and translation in prokaryotes

Answer 9

1) No nucleus and DNA lies in the cytoplasm and therefore both processes occur in tandem (quickly). No transport needed
2) DNA is mostly coding (exons) and therefore processing of non-coding DNA is not required

Question 10

Can genes be expressed with different efficiencies

Answer 10

Yes

Question 11

Difference between DNA and RNA

Answer 11

RNA: single stranded short polymer that has a uracil base
DNA: double stranded long polymer that has a thyamine base

Question 12

What is mRNA

Answer 12

RNA molecules copied from genes which direct synthesis of proteins

Question 13

What are the RNA subtypes

Answer 13

Transfer RNA (tRNA)
ribosomal RNA (rRNA)
small nuclear RNA (snRNA)

Question 14

What’s the most abundant RNA subtype

Answer 14

rRNA, it fractions into 2 band, 28s and 18s

Question 15

What dose transcription produce

Answer 15

RNA complementary to one strand of DNA

Question 16

Whar does transcription being with

Answer 16

The opening and unwinding of small small portion of double helix to expose bases on each DNA strand