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Chapter 3
Cells
Term | Definition |
---|---|
active transport | transport process in which solutes move from areas of lesser to greater concentration: requires energy in the form of ATP |
cilia | hair-like processes on the surface of the cell that propel materials across a surface |
cytoplasm | the gel-like substance surrounding the nucleus and filling the cell |
deoxyribonucleic acid (DNA) | large polymer of nucleotide that carries the genetic information of a cell |
diffusion | a passive transport mechanism that involves the movement of particles from an area of higher to lower concentraion |
endocytosis | form of vesicular transport that brings substances into the cell |
exocytosis | form of vesicular transport that releases substances outside the cell |
facilitated diffusion | transport process involving the diffusion of a substance through a channel protein |
filtration | transport process in which water and dissolved particles are forced across a membrane from an area of higher pressure |
golgi apparatus | prepares proteins and packages them for export to other parts of the body |
hydrostatic pressure | pressure exerted by water |
hypertonic | pertains to a solution that contains a higher concentration of solutes compared to the fluid within the cell; the cell will shrink |
hypotonic | pertains to a solution that contains a lower concentration of solutes compared to the fluid within the cell; the cell will swell |
isotonic | pertains to a solution in which the concentration of solutes in the solution is the same as the concentration of solutes in the cell; the cell remains the same |
microvilli | folds of a cell membrane that greatly increases the surface area of a cell to facilitate absorption |
mitochondria | organelle that converts organic compounds to ATP |
mitosis | type of cell division in which the "mother" cells split into two identical daughter cells |
nucleus | the cell's "control center" that contains a complete set of 46 chromosomes |
organelles | the structure within the cell that performs a specific task in cellular metabolism |
osmosis | a passive transport mechanism involving the diffusion of water from an area of greater concentration of water and a lesser concentration of solutes to an area of lesser concentration of water and greater concentration of solutes |
osmotic pressure | water pressure that develops in a solution as a result of osmosis |
phagocytosis | process in which large particles are trapped in the plasma membrane and brought into the cell |
pinocytosis | process in which fluid and dissolved particles are trapped in the plasma membrane and brought into the cell |
plasma membrane | the external boundry of the cell |
polymer | large molecule consisting of many smaller molecules joined in sequence |
ribonucleic acid (RNA) | nucleotide that assists in protein synthesis |
ribosomes | granules of protein and RNA scattered throughout the cytoplasm: some are attached to the endoplasmic reticulum |
nerve cells | long extensions allow these cells to quickly transmit electrical impulses form one part of the body to another |
muscle cells | elongated, thread-like fibers can shorten to allow body parts to move |
red blood cells | concave shape allows these cells to bend and squeeze through tiny vessels |
gland cells | intracellular sacs store and release substances, such as hormones, enzymes, mucus, and sweat |
immune cells | these cells can recognize and destroy foreign invaders (viruses, fungi, and bacteria). some engulf or destroy foreign cells directly; others manufacture antibodies |
selective permeability | some substances pass through the membrane while others do not |
chromatin | thread-like structures composed of DNA and protein |
chromosomes | rod-like structures that are tightly coiled chromatin |
flagella | hair-like projection that are thicker and longer than cilia and move with a whip-like motion |
sodium-potassium pump | regulates the volume of fluid within cells and provides electrical potential for nervous system activity and helps in heat production |