Lysosomes are membrane-enclosed organelles filled with soluble hydrolytic enzymes that digest macromolecules.

TLS Online TPP Program

#Id: 7959

#Section 3: Genetics, Cellular and Molecular Biology

Unfolded-protein response

Key protein –Ire1 promotes formation of Hac1

TLS Online TPP Program

#Id: 7958

#Section 3: Genetics, Cellular and Molecular Biology

The efficient formation of disulfide bonds in the lumen of the ER depends on the enzyme protein disulfide isomerase (PDI), which is present in all eukaryotic cells

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#Id: 7957

#Section 3: Genetics, Cellular and Molecular Biology

Immediately after the entire precursor, Glc3Man9(GlcNAc)2 is transferred to a nascent polypeptide, three different enzymes, called  glycosidases, remove all three glucose residues and one particular mannose residue.

TLS Online TPP Program

#Id: 7956

#Section 3: Genetics, Cellular and Molecular Biology

A branched oligosaccharide containing 

3 glucose (Glc)

9 mannose (Man)

2 N-acetylglucosamine (GlcNAc)

Glc3Man9(GlcNAc)2

TLS Online TPP Program

#Id: 7955

#Section 3: Genetics, Cellular and Molecular Biology

Only asparagine residues in the tripeptide sequences Asn-X-Ser and Asn-X-Thr (where X is any amino acid except proline) are substrates for oligosaccharyl transferase.

TLS Online TPP Program

#Id: 7954

#Section 3: Genetics, Cellular and Molecular Biology

The precursor oligosaccharide is transferred from a

dolichol lipid anchor to the asparagine as an intact unit in a reaction catalyzed by a transmembrane oligosaccharyl transferase enzyme complex.