You need to determine the sequence of a linear decapeptide. The following experiments have been performed: 1. Edman degradation generates 10 amino acids: Q, E, M, R, K, C, F, P, Y, A.
2. Cyanogen bromide (CNBr) cleavage gives two pentapeptides (5 aa’s).
3. Trypsin cleavage gives two tripeptides (AMR and QFK), and a tetrapeptide.
4. Chymotrypsin cleavage gives a dipeptide QF, a single amino acid, and a heptapeptide (7).
5. The C-terminal residue is identified as Cys using carboxypeptidase C, which removes amino acids from the C-terminal end of a polypeptide.
Give two possible sequences for the decapeptide, using aa three-letter codes.

The two possible sequences for the decapeptide using a three-letter codes

are :

ii) Q F K   A   M R P E Y C

II) Q F K   A   M R E P Y C

Explanation:

The two possible sequences for the decapeptide using a three-letter codes

are :

ii) Q F K   A   M R P E Y C

II) Q F K   A   M R E P Y C

This possible sequences are gotten from Edman degradation , Cyanogen bromide and Trypsin digestion and also Chymotrypsin digestion. also note that the codons used to code these amino acids can also be written  in a sequence to obtain a three code sequence

Endoplasmic reticulum (ER)

Explanation:

The endoplasmic reticulum is present in the cytoplasm of eukaryotic cells.

It forms an interrelated network of:

ER performs several functions that particularly include production, processing, modification and transport of proteins and lipids.