Granular, threadlike material composed of DNA and histone proteins. DNA constitutes the genes
Membranous sacs containing acid hydrolases
Sites of intracellular digestion
Protein fibers; composition varies
The stable cytoskeleton elements; resist mechanical forces acting on the cell
Membranous sacs of oxidase enzymes
The enzymes detoxify a number of toxic substances; the most important enzyme, catalase, breaks down hydrogen peroxide
Movement of a substance through a membrane against a concentration (or electrochemical) gradient; required a membrane carrier protein. Movement of amino acids and most ions across the membrane.
Cylindrical structures made of tubulin proteins
Support the cell and give it shape; involved in intracellular and cellular movements; form centrioles
Cellular region between the nuclear and plasma membranes; consists of fluid cytosol, containing dissolved solutes, inclusions (stored nutrients, secretory products, pigment granules) and organelles, the metabolic machinery of the cytoplasm
Fine filaments of the contractile protein actin
Involved in muscle contraction and other types of intracellular movement; help form the cell's cytoskeleton
Simple diffusion of water through a selectively permeable membrace. Movement of water into and out of cells via membrane pores
Paired cylindrical bodies, each composed of nine triplets of microtubules
"Cell drinking": Plasma membrane sinks beneath an external fluid droplet containing small solutes; membrane edges fuse, forming a fluid filled vesicle. Occurs in most cells; important for taking in solutes by absorptive cells of the kidney and intestine
A stack of smooth membranous sacs and associated vesicles close to the nucleus
Packages, modifies, and segregates proteins for secretion (release) from the cell, inclusion in lysosomes, and incorporation into the plasma membrane
Double-membrane structure; pierced by the pores; outer membrane continuous with the cytoplasmic ER. Separates the nucleoplasm from the cytoplasm and regulates passage of substances to and from the nucleus.
Nucleoli - Dense spherical bodies; composed of ribosomal RNA and proteins. Site of ribosome subunit manufacture
Movement of water and solutes through a semipermeable membrane from a region of higher hydrostatic pressure to a region of lower hydrostatic pressure, that is, along a pressure gradient. Movement of water, nutrients and gases through a capillary wall, formation of kidney filtrate