Transcription

Question 1

Transcription

Answer 1

The first step in protien synthesis.

Question 2

First step

Answer 2

DNA is transcribed by an enzyme called RNA polymerase. A specific nucleotide sequence (called the promoter) on the DNA molecule causes RNA polymerase to attach to the DNA.

Question 3

Second step

Answer 3

An enzyme causes the DNA strand to unwind and RNA polymerase transcribes a single strand of DNA (the template strand) into a single-stranded RNA polymer called messenger RNA (mRNA). Like DNA, RNA is composed of nucleotide bases. RNA nucleotides attach to each other based on the base pairing rule. However, when RNA polymerase transcribes the DNA, uracil (U) binds to adenine, rather than the thymine (T) found in DNA.

Question 4

Third step

Answer 4

RNA polymerase moves along the DNA until it reaches a terminator sequence. At this point, RNA polymerase releases the mRNA polymer and detaches it from the DNA. The DNA recoils back into the helical shape.

Question 5

Forth step

Answer 5

Since proteins are constructed by ribosomes found in the cytoplasm, mRNA leaves the nucleus via pores in the nuclear membrane.

Question 6

What is a coding strand

Answer 6

A coding strand is similar to the mRNA strand. It contains C,G and but instead of U it has T. While the mRNA strand has U.

Purpose: COmplimentary to the mRNA strand.