Question

1) What will happen if you swap a common codon with a rare one in an mRNA?

a) destabilize mRNA via NMD

b) increase rate of protein synthesis

c) no effect on the rate of protein synthesis

d) slow the rate of protein synthesis

2) why are some Toll-like receptors found within endosomes?

a) they bind to PAMPs on intracellular pathogens

b) they bind to PAMPs on extracellular pathogens

c) they bind to PAMPs on endosomal proteins

d) they bind to PAMPs on endosomal RNAs

e) All answers are correct

Answer 1

1) Answer:- (d) slow the rate of protein synthesis.

Explanation:- Rare codons are those which are used rarely or infrequently in the genome as a codon with usage frequency lower than the alternative codon which codes for the same amino acid. If I swap a normal codon with a rare codon then it may arrest the translation process due to the rarity of their cognate tRNAs.

2) Answer:- e) all the answers are correct.

Explanation:- Endosome is a membrane bound organelle in eukaryotes originating from the trans Golgi network.
Toll like receptors or TLRs are a class of proteins that play an important role in innate immune system. These are usually expressed on sentinel cells such as dendritic cells macrophages etc and identifies structurally conserved molecules derived from microbes.

PAMPs means Pathogeniated associated molecular patterns and the receptor which recognises them is called pattern recognition receptors (PRRs). TLRs are one important kind of PRR.
As TLRs are expressed at cell surface as well as endogenously (inside the cell). That can bind to microbial nucleic acid from virus or any other organisms. It also has been suspected to bind to the proteins(fibrinogen) derived from the host molecules and can form complex with endogenous proteins.