the movement of ions or molecules across a cellular membrane from a lower concentration to a higher concentration, requiring energy
The movement of molecules or ions from a region of higher concentration to a region of lower concentration
Separates cell from its environment. Controls movement of substances into / out of the cell
Organizes the cell's microtubules. Contains centrioles which appear to help in organizing cell division.
Clear, thick, jellylike material which supports and protects cell organelles; provides chemical environment for organelles
Endoplasmic Reticulum (ER)
A network of sacs that manufactures, processes, and transports chemical compounds for use inside and outside of the cell.
Organelle that modifies, sorts, and packages proteins from the endoplasmic reticulum and send proteins to their final destination
Primarily structural in function and are an important component of the cytoskeleton.
Responsible for protecting the cell from its own production of toxic hydrogen peroxide. (As an example, white blood cells produce hydrogen peroxide to kill bacteria. The oxidative enzymes in peroxisomes break down the hydrogen peroxide into water and oxygen)
Involves the intake of a large droplet of extracellular fluid which has large particles in it (i.e. bits of organic matter or bacteria)
Receptor assisted endocytosis
Involves the intake of specific molecules(ex. Cholesterol) through the aid of special membrane proteins
The reverse of endocytosis. Involves the movement of a vesicle from inside the cell to the cell surface in which its contents are excreted into the surrounding environment (ex. Insulin secreted by pancreatic cells)
A cell characterized by the presence of a nucleus and other membrane-bound organelles. Eukaryotes can be unicellular (protists) or multicellular (fungi, plants and animals).