There are about 90 million rod cells in the human retina, and each contains about 4x107 molecules of rhodopsin that are very densely packed in the membrane disks.

TLS Online TPP Program

#Id: 7949

#XL - Q Biochemistry

A branched oligosaccharide containing

3 glucose (Glc)

9 mannose (Man)

2 N-acetylglucosamine (GlcNAc)

Glc3Man9(GlcNAc)2

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#Id: 7948

#XL - Q Biochemistry

Biosynthesis of all N-linked oligosaccharides begins in the rough ER with a preformed oligosaccharide precursor containing 14 residues.

TLS Online TPP Program

#Id: 7947

#XL - Q Biochemistry

N-linked oligosaccharides

carbohydrate chains attached to the amide nitrogen of asparagine

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#Id: 7946

#XL - Q Biochemistry

O-linked oligosaccharides

Carbohydrate chains in glycoproteins attached to the

hydroxyl group (-OH) in serine and threonine residues

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#Id: 7945

#XL - Q Biochemistry

Glycoproteins

Proteins with attached carbohydrates

TLS Online TPP Program

#Id: 7944

#XL - Q Biochemistry

Membrane and soluble secretory proteins synthesized on the rough ER undergo four principal modifications before they reach their final destinations: 

(1) Glycosylation in the ER and Golgi complex

(2) Formation of disulfide bonds in the ER

(3) Proper folding of polypeptide chains and assembly of multisubunit proteins in the ER

(4) Specific proteolytic cleavages in the ER, Golgi complex, and secretory vesicles