LDL receptors on cell membrane, illustration. The binding of LDL (low-density lipoprotein) droplets (spherical lipid particles) to the LDL receptors (purple) results in the endocytosis of this biochemical molecule through the cell membrane into...

Calcium channel pore, illustration. This is the calcium released-activated calcium (CRAC) channel (red) embedded in a cell membrane. It consists of a hexameric assembly of subunits around a central ion pore. The channel shows selective permeability to...

Illustration of chloride channels (purple) in a cell membrane. Chloride channels conduct chloride anions (yellow) across cell membranes, regulating the electrical excitation of neurons and muscles and the flow of salt and water across epithelial...

Opioid and cannabinoid brain receptors, illustration. Two types of receptors are shown here in a brain cell membrane. The membrane is seen in cutaway view across lower centre, with two brain cell receptors (dark blue) shown: a delta opioid receptor...

Amyloid precursor protein at cell membrane, illustration. The amyloid precursor protein (APP, centre) is a complex protein with many functions. It is found on the surface of cells throughout the body. The intact protein binds to many stuctural...

CAR T cell cancer immunotherapy, illustration. Chimeric antigen receptor (light blue, centre) binding to CD19 molecules (pink, lower right and lower left) on a leukaemia (blood cancer) cell. The CAR receptors are genetically engineered and embedded in...

Illustration of the outer surface of a cell membrane. Transmembrane proteins (purple) and glycolipids (yellow) protrude from the membrane's surface. At upper left is an LDL (low-density lipoprotein) receptor bound to an LDL particle (large, orange and...

CAR T cell cancer immunotherapy. Illustration of the membrane of a cell involved in CAR (chimeric antigen receptor) T cell immunotherapy, a process that is being developed to treat cancer. In this process, T cells (part of the immune system) are...

Illustration of a chimeric antigen receptor (CAR) spanning the cell membrane of a T-cell, a white blood cell of the immune system. This T-cell has been taken from a cancer patient and then genetically engineered to produce CARs on its surface that...

Programmed cell death in immune system, illustration. The protein PD-1 (programmed cell death protein 1, red) is seen extending from the surface membrane of a T-cell (across bottom), interacting with the ligand protein PD-L1 (orange) from an antigen...

Bacterial wall and antibiotic resistance

THC binding to cannabinoid receptors, illustration. Tetrahydrocannabinol (THC, green molecules) is the main psychoactive constituent of cannabis. It is used to treat nausea and vomiting during chemotherapy. The cannabinoid receptor (pink; embedded in...

T-cell receptor-MHC-antigen complex

Phase contrast light micrograph of Paramecium. (Paramecium multimicronuleatum), a ciliate protozoan, with oral groove (right side of cell), no food vacuoles, two contractile vacuoles (left side of cell; no radiating channels), nucleus (centre) and...

Zika viruses, illustration

Zika viruses, illustration

Nerve synapse, illustration.

Nerve synapse, illustration

Sucrose-specific porin molecule

ATP synthase molecule

ATPase molecule

ATPase molecule

Clathrin Mediated Endocytosis

Anatomy of the organ of Corti, part of the cochlea of the inner ear.

Cell membrane with receptors and ion channels, illustration