Chapter 3 (The Cell)
cell theory - Idea that all living things are composed of cells, cells are the basic units of structure and function in living
... [Show More] things, and new cells are produced from existing cells.
prokaryotic cell - A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea. They are single celled organisms that are neither plant nor animal.
organelle - A subcellular structure that performs specific functions in eukaryotic cells.
eukaryotic cell - A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Examples of organisms with these cells are protists, plants, fungi, and animals.
plasma membrane - A flexible boundary that controls the movement of substances into and out of the cell.
cytoplasm - A jellylike fluid inside the cell in which the organelles are suspended.
selectively permeable - A feature and a function of the plasma membrane that is essential to maintain homeostasis by regulating the passage of some substances while preventing others from entering the cell.
cell adhesion molecule - Proteins that allow cells to hook together and form attachments to the cytoskeleton for maintaining cellular shape.
simple diffusion - In this passive membrane process, molecules are moving from an area of higher concentration to an area of lower concentration. This molecular movement means moving down the concentration gradient.
concentration gradient - A difference in the concentration of a substance across a distance
facilitated diffusion - Movement of specific molecules across cell membranes through protein channels.
osmosis - Diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal.
hypertonic solution - A solution in which the concentration of solutes is greater than that of the cell that resides in the solution.
isotonic solution - A solution with the same concentration of water and solutes as inside a cell, resulting in the cell retaining its normal shape because there is no net movement of water.
hypotonic solution - A solution in which the concentration of solutes is less than that of the cell that resides in the solution
active transport - Movement of substances from low to high concentration using selective carrier proteins, requiring energy in form of ATP
endocytosis - Cell membrane forms a pouch around the substance. The pouch closes and pinches off from the membrane to form a vesicle inside the cell.
vesicle - A membrane bound sac that contains materials involved in transport of the cell.
phagocytosis - "Cell Eating" of large particles.
pinocytosis - Cell drinking; uptake of liquid by a cell.
exocytosis - A process in which a vesicle inside a cell fuses with the cell membrane and releases its contents to the external environment. Transports to outside of cell.
nucleus - A membrane-bound organelle in the cell that contains DNA.
nuclear envelope - A double membrane perforated with protein-lined pores that control the flow of materials into and out of the nucleus.
nuclear pore - Allows the exchange of materials through openings in the nuclear envelope. Particularly proteins and RNA.
chromosome - Threadlike structures within the nucleus made in DNA and proteins called the histones.
nucleolus - A specialized structure in the nucleus, formed from various chromosomes and active in the synthesis of ribosomes.
ribosome - A cell organelle constructed in the nucleolus and functioning as the site of protein synthesis in the cytoplasm; consists of rRNA and protein molecules, which make up two subunits.
endoplasmic reticulum - A series of membranes forming sacs and tubules that extends from the outer nuclear membrane into the cytoplasm. [Show Less]