Question

-Which elements are found in a eukaryotic promoter vs. a prokaryotic promoter?

-what is the concept of (restriction enzyme produced) DNA fragment separation by gel electrophoresis

-what are the steps and process of thermal cycling?

-what is the restriction enzyme(s) and how do you know when they leave blunt or sticky ends (ie. XbaI, SmaI, EcoRI, BamHI)?

-The lac and trp operons (form a figure showing the operon).

- What is RNA silencing involvee (in general, what is RNA interference; what kinds of molecules are involved)? How can it affect gene expression?

please help!!!!

Answer 1

Ans) The eukaryotic and prokaryotic promoters are different from each other. In the prokaryotic promoter, it consists of two short sequences at -10 and -35 position upstream of transcription start site. The site that is present at -10 is Pribnow box and consists of the TATAAT sequence. This helps in initiating the transcription. The -35 sequence element consists of TTGACA and helps in accelerating transcription rate.

In case of the eukaryotic promoters, they lie upstream of gene that needs to be transcribed and most of them consist of TATA box. The promoters consist of regulator regions which are enhancers, silencer, insulators etc. which helps in transcription. The TATA box is close to the transcription site. The TATA box is responsible for formation of transcription complex.

Ans) The restriction enzymes are responsible for cutting the DNA at specific sites and they are used in cutting the DNA into fragments so that they are sorted in electrophoresis. These restriction enzymes bind to specific sequences and it helps in separating the DNA fragments based on their size which helps in analyzing the DNA sequence.