Cell Biology

Learn how passive transport moves substances across cell membranes without direct ATP use, including simple diffusion, facilitated diffusion, osmosis, and examples.

Membrane proteins are proteins found within the lipid bilayer or attached to the surface of biological membranes. They form an important component of the plasma membrane and the membranes surrounding different cell organelles. Based on their association with membrane, the proteins are mainly of three types, integral membrane proteins, peripheral membrane proteins, and lipid-anchored proteins.

Learn what monocytes are, their structure, three human monocyte types, immune functions, development, normal blood count, and what high or low levels mean.

Learn what the cytoplasmic matrix or cytosol is, its composition and properties, major cellular functions, and how it differs from cytoplasm and cytoskeleton.

Learn the extrinsic pathway of apoptosis, from death-receptor activation and DISC formation to caspase-8, executioner caspases, BID crosstalk, and regulation.

Learn how the intrinsic pathway of apoptosis is triggered and regulated, from BCL-2 proteins and MOMP to cytochrome c release, apoptosome formation, caspase-9, and cell death.

Learn what platelets (thrombocytes) are, how they are formed, their structure and functions, normal platelet count, and their role in hemostasis and blood clotting.

Storage granules are bacterial cell inclusions that store carbon, phosphate, sulfur, and nitrogen reserves. Learn their types, structure, functions, formation, and identification.

Cilia are membrane-covered, microtubule-based projections that extend from the surface of many eukaryotic cells. Motile cilia generate movement of cells, fluids, or particles, whereas most primary cilia function as specialized sensory and signaling compartments. Their structure centers on an axoneme anchored to the cell by a basal body. What Are Cilia? Cilia are short hair-like

Learn the fluid mosaic model of the plasma membrane, including its definition, structure, components, features, membrane fluidity, evidence, limitations and modern modifications.