Studied by 27 people
prokaryotic cell
unicellular organism that lacks a nucleus
eukaryotic cell
organism whose cells contain a nucleus
cytoplasm
fluid portion of the cell outside the nucleus
ribosome
cell organelle consisting of RNA and protein found throughout the cytoplasm in a cell; the site of protein synthesis
endoplasmic reticulum
internal membrane system found in eukaryotic cells; place where lipid components of the cell membrane are assembled
Golgi apparatus
organelle in cells that modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell
chloroplast
organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy
mitochondria
cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use
cell wall
strong, supporting layer around the cell membrane in some cells
cell membrane
thin, flexible barrier that surrounds all cells; regulates what enters and leaves the cell
phospholipid bi-layer
the structure of the cell membrane consisting of a two-layered sheet
selectively permeable
property of cell membrane that allows some molecules to pass through it while others cannot
phospholipid
the building block of the cell membrane; makes up the phospholipid bi-layer
hydrophobic
hydrophilic
protein channel
channel that allows specific proteins to enter and exit the cell; located in the cell membrane
concentration gradient
osmosis
diffusion of water through a selectively permeable membrane
aquaporins
channel in the cell membrane for H2O molecules to pass
hypotonic
when comparing two solutions, the solution with the lesser concentration of solutes
isotonic
when the concentration of two solutions is the same
hypertonic
when comparing two solutions, the solution with the greater concentration of solutes
passive transport
diffusion
process by which particles tend to move from an area where they are more concentrated to an area where they are less concentrated
facilitated diffusion
process of diffusion in which molecules pass across the membrane through cell membrane channels
active transport
endocytosis
exocytosis
homeostasis
relatively constant internal physical and chemical conditions that organisms maintain
positive feedback loop
negative feedback loop
stimulus
signal to which an organism responds
effector
receptor
on or in a cell, a specific protein to whose shape fits that of a specific molecular messenger, such as a hormone
