Cells Ch3

the structural units of all living things

the outer boundary of the cell

the intracellular fluid packed with organelles (small structures that perform specific cell functions)

the cellular material surrounding the nucleus and enclosed by the plasma membrane

series of integral protein molecules in the plasma membranes of adjacent cells fuse together, forming an impermeable junction that encircles the cell

"binding bodies"  anchoring functions - mechanical couplings scattered like rivets along the sides of abutting cells to prevent separation

"nexus" - communicating junction b/w adjacent cells.  cells connected by hollow cylinders called connexons, composed of transmembrane proteins

• extracellular fluid that is derived from the blood. 
• contains 1000's of ingredients, including amino acids, sugars, fatty acids, vitamins, regulatory substances - hormones and neurotransmitters, salts, and waste products
• like a nutritious soup

the measure of the total concentration of solute particles

*when solutions of different osmolarity are separated by a membrane, osmosis occurs until equilibrium is reached

the fuzzy, sticky, carbohydrate-rich area at the cell surface

the ability of a solution to cause a cell to shrink or swell by altering the cells internal water volume

• "cell forming material"
• cellular material b/w plasma membrane and nucleus, is the site of most cellular activities

• viscous, semitransparent fluid in which other cytoplasmic elements are suspended
• complex mixture w/properties of both a colloid and a true solution

• metabolic machinery of the cell
• each type carries out specific function for the cell

• chemical substances that may or may not be present, depending on cell type
• eg-- stored nutrients, lipid droplets in fat cells, pigment (melanin) granules in certain skin and hair cells...

highly reactive chemicals w/unpaired electrons that can scramble the structure of biological molecules

small tubes formed by microtubules

structures in the nucleus that carry the hereditary factors (genes)

• barlike bodies of tightly coiled chromatin
• visible during cell division

the mechanism of DNA replication

segment of DNA w/blueprint for one polypeptide

each 3-base sequence on DNA is represented by a codon

complementary 3-base sequence on mRNA

3-base sequence complementary to the mRNA codon

each sequence of three-base

short-chain RNA molecules that transfer amino acids to the ribosome

constituent of ribosome, exists within the ribosomes of cytoplasm and assists in protein synthesis

long nucleotide strands that reflect the exact nucleotide sequences of the genetically active DNA and carry the DNA's message

a process of controlled cellular suicide, eliminates cells that are unneeded, stressed, or aged

an= without; plas= to grow

abnormalities in cell structure and loss of differentiation

example- cancer cells typically lose the appearance of parent cells and come to resemble undifferentiated or embryonic cells

dys= abnormal

a change in cell size, shape, or arrangement due to chronic irritation or inflammation (infections, etc)

• growth of an organ or tissue due to an increase in the size of its cells
• normal response of skeletal muscle cells when they are challenged to lift excessive weight
• differs from hyperplasia, which is an increase in size due to an increase in cell #

• hollow microscopic sacs formed of phospholipids that can be filled w/a variety of drugs
• serve as multipurpose vehicles for drugs, genetic material, and cosmetics

• a change in DNA base sequence that may lead to incorporation of incorrect amino acids in particular positions in the resulting protein
• the affected protein may remain unimpaired or may function abnormally or not at all, leading to disease

• death of a cell or group of cells due to injury or disease
• acute injury causes cells to swell and burst, and induces the inflammatory response (this is uncontrolled cell death, in contrast to apoptosis)

diffusion of a solvent through a membrane from a dilute solution into a more concentrated one