March 1, 2019

DNA and protein synthesis

 

  1. How is mRNA different than DNA?

DNA carries the instructions to build protein, it is big and has two backbones. mRNA is single-sided and short, it copies the information carried by 1 gene on DNA and carried this message to the ribose. The function of DNA and mRNA are different.

  1. Describe the process of transcription

When one DNA translated into mRNA, the process is called transcription. The transcription takes few steps, the first step is that a specific section of DNA unwinds, exposing one gene. Then alone 1 strand, the complimentary RNA bases bond, at this time, inside of T bonded with A, Uracil will bond with DNA’s Adenine. The enzymes – RNA polymerase will make adjacent nucleotides form covalent bonds and build RNA backbone. Now DNA is released, DNA reforms double helix.

  1. How did today’s activity do a good job of modelling the process of RNA transcription? In what ways was our model inaccurate

In today’s activity, I understand how transcription is that make DNA translate into mRNA. The different colour of the back bone makes me have a better understanding of how different DNA and mRNA is. The model is inaccurate because a usual size of DNA which make the mRNA would be much bigger than the only 18 base-pairs that we made in this model.

This photo shows how the mRNA is made

  1. Describe the process of translation: initiation, elongation, and termination

Initiation is mRNA binds to small ribosome subunit, then the two ribosome subunits bind together.

Elongation ribosome holds mRNA and allows complimentary tRNA to attach to binding sites, then tRNA binds to P site, another tRNA binds to A site, “empty” tRNA leaves ribosome.

Termination is that the elongation cycle continues until mRNA reads a stop codon.

  1. How did today’s activity do a good job of modelling the process of translation? In what ways was our model inaccurate?

Today’s activity let us built a protein through the DNA to mRNA, then finally get protein. The transcription part is not that much because we did it last time, it is more focus on how translation works to make protein. The P site and A site is very clear when I did this activity and helps me understand how everything works. It might be inaccurate if we couldn’t translate the mRNA well and also it is easy to make mistakes that the amino acid is match with the codon on the mRNA strand but not the anticodon.

transection — DNA translate into mRNA

elongation — start with P site

after P site, the A site is also start matching

after A site matched, the A site move to P site and match the A site again

the protein after the whole process (translation), it stops when their is a stop codon.