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Cells A&P

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cell
basic unit of life
cell differentiation
process by which a cell becomes specialized for a specific structure or function
tissue
group of similar cells that perform a particular function
nucleus
control center of the cell; contains DNA
cytoplasm
material between the cell membrane and the nucleus
plasma membrane
thin flexible barrier that regulates what enters and exits the cell; composed of two layers of lipids
nucleolus
small, dense region within most nuclei in which the assembly of proteins begins
nuclear membrane
highly porous membrane that separates the nucleus from the cytoplasm
chromatin
long strands of DNA wrapped around proteins; condenses to form chromosomes
nuclear pore
regulates materials passing through nuclear membrane
intracellular fluid
fluid residing inside the cells that provides the medium for cellular reactions
extracellular fluid
all body fluid other than that contained within cells; includes plasma and interstitial fluid
cytosol
fluid portion of the cytoplasm
organelle
specialized structure that performs specific functions within cell
free ribosome
floats around in cytoplasm; makes proteins that will stay within the cell
fixed ribosome
ribosome bound to the endoplasmic reticulum; makes proteins for export outside the cell
smooth endoplasmic reticulum
no attached ribosomes; three main functions: intracellular transport, lipid synthesis, drug and alcohol detoxification
rough endoplasmic reticulum
has attached ribosomes; produces membrane and secretory proteins
Golgi apparatus
stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum
lysosome
organelle that contains digestive enzymes
peroxisome
organelles that contain the hydrogen peroxide produced by lipid metabolism; convert the toxic hydrogen peroxide to water and oxygen using catalase
mitochondria
organelles that convert the chemical energy stored in food into ATP through cellular respiration
cytoskeleton
network of protein fibers that holds the cell together, helps the cell to keep its shape, and aids in movement
microfilament
thin, solid protein fibers that provide structural support for the cell
microtubule
tubes of protein; form the mitotic spindle during cell division, form cilia and flagella, and are used for intracellular structure and transport
microvilli
projections that increase the cell's surface area
cilia
short, hair-like structures made of microtubules that enable movement of cells or movement of materials outside a cell
flagellum
hair-like projection on a sperm cell that makes it motile
phospholipid bilayer
double layer of phospholipids that makes up plasma and organelle membranes
selective permeability
property of the plasma membrane that allows it to control movement of substances into or out of the cell
passive transport
movement of materials through a cell membrane without using energy
active transport
energy-requiring process that moves material across a cell membrane against a concentration gradient
simple diffusion
movement of molecules across the cell membrane from high to low concentration
osmosis
diffusion of water
isotonic
when the concentrations of solutes outside and inside the cell are equal
hypotonic
when the concentration of solute molecules outside the cell is lower than the concentration in the cytosol
hypertonic
when the concentration of solute molecules outside the cell is higher than the concentration in the cytosol
facilitated diffusion
movement of specific molecules across cell membranes from high to low concentration through protein channels
exchange pump
carrier mechanism that moves ions in opposite directions against their concentration gradients requiring energy
exocytosis
process by which vesicles release their contents outside the cell by fusing with the cell membrane
endocytosis
process by which a cell takes material into the cell by infolding of the cell membrane to form a vesicle
phagocytosis
process in which extensions of cytoplasm surround and engulf large particles and take them into the cell
pinocytosis
process by which certain cells engulf extracellular fluid
interphase
period of the cell cycle between cell divisions
mitosis
division of the cell nucleus
prophase
first and longest phase of mitosis, during which the chromosomes become visible
metaphase
second phase of mitosis, during which the chromosomes line up across the center of the cell
anaphase
third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles
telophase
last phase of mitosis, chromosome are in two new cells and nuclear membranes start to reform
cytokinesis
division of the cytoplasm
cancer
uncontrolled cell division
tumor
a mass of abnormal cells
benign
not cancerous
malignant
cancerous
metastasis
process by which cancer cells spread from their original site through blood or lymph
epithelium
tissue that covers all free surfaces of the body
connective tissue
tissue that binds, supports, and protects body structures, includes cartilage, tendons, fat, blood
avascular
lacking a blood supply
vascular
containing blood vessels
glia
provide physical and functional support to neurons in the brain and spinal cord
irritability
ability to respond to stimuli
conductivity
ability to conduct an electric current
stem cell
unspecialized cell that can develop into a specialized cell under the right conditions