MCQs

Mannose-6-phosphate serves as a specific molecular sorting signal that targets newly synthesized hydrolytic enzymes to the lysosomes.

Human ABO blood group determinants are defined by the structural variations of carbohydrate chains on surface glycolipids and glycoproteins.

The glycocalyx acts as a cellular fingerprint; individual combinations of sugar chains allow immune cells to distinguish self from non-self.

Hydroxyl groups on sugar residues form hydrogen bonds with surrounding water molecules, rendering the region highly hydrophilic.

Lipopolysaccharides (LPS) contain a lipid A anchor component covalently bound to a core oligosaccharide and an O-antigen chain.

Mucus contains mucins, which are heavily glycosylated glycoproteins that trap pathogens and protect delicate mucosal surfaces.

Ribosomes are functional structural complexes consisting of ribosomal RNA (rRNA) and specific ribosomal proteins working together.

Hemoglobin is a metalloprotein containing an iron-porphyrin ring system called a heme group as its functional prosthetic group.

The Golgi apparatus contains specific glycosyltransferase enzymes that trim and add sugar residues to complete glycoprotein processing.

Conjugated molecules like glycoproteins and glycolipids are stable because their components are bound via permanent covalent linkages.

N-linked glycosylation begins in the lumen of the rough endoplasmic reticulum as polypeptides are being translated by ribosomes.

Glycoproteins and glycolipids extend their sugar chains outward to form the glycocalyx, which mediates cellular identification.

Lipoproteins feature a hydrophilic protein shell that encloses a hydrophobic lipid core, allowing transport in aqueous blood plasma.

Galactolipids and cerebrosides, which are types of glycolipids, are heavily concentrated in the nervous system's myelin sheath.

Histones are basic proteins that bind tightly to the acidic phosphate backbone of DNA, creating a conjugated nucleoprotein complex.

Immunoglobulins (antibodies) and cell-surface receptors are functionally classified as glycoproteins due to their oligosaccharide chains.

Glycolipids are formed when carbohydrate groups (oligosaccharides) attach covalently to fatty acids or glycerol backbones within membranes.

Conjugated molecules consist of a basic biomolecule chemically bound to a distinct, non-protein or structural component termed a prosthetic group.

Replacing the 2'-OH group removes the nucleophile required for autophilic attack, making the synthetic RNA highly resistant to ribonuclease degradation.