MCQs

Acetylation neutralizes the positive charges on histones, weakening their grip on DNA and allowing transcription machinery to bind.

The Lipid A portion of LPS is an endotoxin that can trigger severe inflammatory pathways, leading to toxic shock in host organisms.

Silicoproteins are conjugated molecules where silicon or silicate complexes are structurally integrated into a protein backbone.

Positively charged basic amino acids (lysine and arginine) on histones bind strongly to the negatively charged phosphates of the DNA molecule.

Tay-Sachs is a lysosomal storage disorder where the inability to break down membrane gangliosides leads to toxic buildup in neurons.

Lectins are specialized proteins that recognize and bind specific carbohydrate structures, facilitating cell-to-cell contact.

Telomerase requires its intrinsic RNA component to serve as a matching template for the synthesis of telomeric DNA chromosome ends.

Ceruloplasmin is a specialized transport protein and enzyme that binds copper ions tightly, making it a conjugated metalloprotein.

Scurrying pathogens use hydrophilic, slippery glycoprotein capsules to hide their surface markers and evade immune cell engulfment.

As VLDL unloads triacylglycerols into adipose tissues via lipoprotein lipase, it becomes denser and transforms into cholesterol-rich LDL.

Proteoglycans form large aggregates with hyaluronic acid in cartilage, trapping water molecules to resist mechanical compression.

High-density lipoproteins (HDL) have the highest protein-to-lipid ratio and act to clear excess cholesterol from the circulatory pathways.

TMV consists of a single strand of genomic RNA wrapped in a helical coat of capsomere proteins, forming a pure nucleoprotein.

Chylomicrons are large lipoproteins that absorb and transport dietary triacylglycerols and cholesterol from the intestines into lacteals.

Interferons are signaling proteins (cytokines) released by host cells in response to viral pathogens, and they are glycoproteins.

O-linked glycosylation occurs through the covalent attachment of an oligosaccharide to the oxygen atom of serine or threonine side chains.

Viral envelope glycoproteins interact with host cell-surface receptors, mediating viral attachment and entry.

Cytochromes are electron-transporting metalloproteins whose iron center alternates between Fe2+ and Fe3+ states to transfer electrons.

LDL transports cholesterol from the liver to peripheral tissues; excess circulating LDL can oxidize and deposit in arterial walls.