Question

A.) Are glycosylated proteins found in the mitochondria? Why or why not?

B.) Please explaib why integrak membrane proteins are only found to be glycosylated on the extracelluar surface of the protein.

Answer 1

Protein glycosylation is an enzyme-directed chemical reaction that takes place in the ER(Endoplasmic Reticulum) and in the Golgi Apparatus body of the cell.

Protein glycosylation helps in proper folding of proteins, stability and in cell to cell adhesion commonly needed by cells of the immune system. The major sites of protein glycosylation in the body are ER, Golgi body, nucleus and the cell fluid.

Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection, while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins, while automated software tools started replacing manual processing to improve the reliability and throughput of the analysis.

2. You will learn about two types of membrane proteins: peripheral proteins and integral proteins. Peripheral proteins have weaker and temporary connections to the membrane.Integral membrane proteins float in this sea of lipid, held by hydrophobic interactions with their nonpolar amino acid side chains. Both proteins and lipids are free to move laterally in the plane of the bilayer, but movement of either from one face of the bilayer to the other is restricted.