PD-1 has a structure similar to CTLA-4 and when activated negatively regulates T-cell function by inducing apoptosis of activated T cells. 

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.

TLS Online TPP Program

#Id: 9264

#Section 2: General Biology

TLS Online TPP Program

#Id: 3772

#Section 2: General Biology

Matter is anything that takes up space and has mass.

TLS Online TPP Program

#Id: 8154

#Section 3: Genetics, Cellular and Molecular Biology

Sar1 GTPase drives the pinching off of COPII vesicles

ARF GTPase drives the pinching off of COPIvesicles

Dynamin GTPase drives the pinching off of clathrin-coated vesicles

TLS Online TPP Program

#Id: 8094

#Section 2: General Biology

Platelet-activating factor has a long ether-linked alkyl chain at C-1 of glycerol, but C-2 is ester-linked to acetic acid, which makes the compound much more water-soluble than most glycerophospholipids and plasmalogens.