Transcription And Translation

Question 1

What is mRNA?

Answer 1

A transcript copy of a gene used to encode for a polypeptide

Question 2

What is tRNA?

Answer 2

Carries ammino acids

Question 3

What is rRNA?

Answer 3

Primary component of ribosomes

Question 4

What is the process of transcription?

Answer 4

-RNA polymerase binds to a site on DNA at the start of a gene.
-Enzyme separates DNA strands.
-Synthesises a complementary RNA strand from the template strand.
-Does this by covalently bonding adjacent nucleotides forming phosphodiester bonds.
-RNA polymerase detaches from the DNA.
-RNA detaches from the DNA and the double helix reforms.
-The mRNA moves to the cytoplasm from the nucleus.

Question 5

In what process are introns removed before translation?

Answer 5

Splicing

Question 6

What is the process of splicing?

Answer 6

-Introns are removed and broken down by nucleotides.
-Mature mRNA contains only exons and leaves the knuckles for translation.
-The spliceosomes form and causes a loop to form a loop which allows exons to joined and introns removed.
-mRNA leaves through nuclear pores.

Question 7

What are ribosomes made up of?

Answer 7

Proteins and rRNA

Question 8

How is tRNA specialsed?

Answer 8

-Has a sequence of 3 bases complementary to codons on the mRNA (anticodon).
-Is a clover shape not strand.

Question 9

What is the process of translation?

Answer 9

-mRNA leaves nucleus through nuclear pore.
-Ribosome attaches to mRNA at start codon.
-Complementary anticodon is attracted to first codon on the mRNA and forms weak hydrogen bond.
-Repeated for every codon in chain.
-A peptide bond is formed between adjacent nucleotides (needs ATP).
-First molecule of tRNA is detached from ammino acid.
-Ribosome moves along mRNA strand until a stop codon is reached.
-A polypeptide chain is formed and released into cytoplasm.