Question

Fill-in-the blank (36 pts - each answer is worth 1 pts): For each of the following statements, indicate with a P if the statement applies only to prokaryotes, an E if the statement applies only to eukaryotes, and an E and P if the statement applies to both eukaryotes and prokaryotes. (3pts) The 5' end of the mature mRNA begins with a triphosphate. The primary mRNA transcript is inactive. Termination of transcription requires the protein pfactor. 2. Circle the fatty acid in each pair that has the higher melting temperature. (2 pt) (a) 16:0 18:0 (b) 16:145 16:245,12 3. The AGⓇ for isomerization between enantiomers is - (1 pt) S ribosomal subunits form the ribosome found in eukaryotes. (3 pts) 5. The splicesomal component that defines the 5' splice site is The splicesomal component that defines the 3' splice site is _. The short sequence usually marks the 5' end for splicing, while the the short sequence typically makes the 3' end. (4 pts) 6. Indicate whether the following statements are true (T) or false (F). (3 pts) _Ribosomes contain many separate proteins. _The catalytic machinery of the ribosome is protein-based. _There are four binding sites for aminoacyl-tRNAs on a ribosome. 7. There are types of integral membrane proteins. Type - proteins contain a single trans-membrane region with the N-terminus facing the cytosol. Type is made of a single polypeptide chain that crosses the membrane multiple times. (3pts)

Answer 1

1 ;

E, P - 5' end of mature mRNA starts with Triphosphate in both.

E, - primary mRNA transcript inactive in eukaryote not In prokaryotes because prokaryotes have transcription coupled translation without any modifications in mrna but eukaryote need modifications like capping, splicing, poly A tailing.

- P ; prokaryotes requires rho protein for transaction temination.

2. A. 18:0 steric acid then 16:0 palmitic acid has higher melting point.

Melting point decrease with the increase of double bond.

3. ∆G° of Isomerization between Enantiomer is 0 ( zero)

4. 40s and 60s eibosomal subunit form the 80s ribosome found in eukaryote.

40s is smaller subunit has tRNA binding sites like A site P site and E site.

60s is larger subunit has peptidal transferase activity.

5. U1 spliciosome binds at 5' splice site.

U2AF Sliciosome component binds at 3' end of splicing site. And short sequence of G, U, repeat markse the 5' spicing site.

Short sequence of A, G, Repeat mark the 3' splicing site.

6. T ribosomes contains many different protein like L27 protein help in translation, factor binding domain protein which has GTPase activity.

F catalytic machinery of ribosomes also depends on rna molecules as 30s subunit of prokaryotes have 16s rRNA which makes complementary with sine dalgarno sequence of the mRNA.

F there are three binding site for aminoacyl tRNA

a. A site at which newly incoming aminoacyl tRNA binding takes place.

b. P site at which peptidal tRNA are present.

c. E site tRNA without amino acid.

There are six type of integral membrane protein.

Type II protein contain single transmembrane region with N terminus facing towards cytosol and c terminus towards out side.

Type III membrane protein made up of single polypeptide and Crosses the membrane multiple times.