Week 2 - Cell Structure & Function Flashcards
cytoplasm
all the material between the plasma membrane and nucleus
organelles
specialized closed structures within the cell with a specific function
plasma membrane
composed of phospholipids, proteins, cholesterol, glycoproteins and glycolipids; surrounds the cell and regulates what goes in and out
nucleus
structure inside the cell that contains all the information that regulates cell activity
chromatin
genetic material, can condense into chromosomes
nucleolus
dense region that makes ribosomes
nuclear envelope
a double membrane
vesicles
membrane-bound sacs that contain various molecules; acts as storage, importing or exporting different types of molecules
ribosomes
molecular “machines” that synthesize proteins; those attached to the rough ER are called bound ribosomes; those that are free-floating in the cytosol are called free ribosomes
endoplasmic reticulum
a series of interconnected tubes and membranes that are continuous with the outer membrane of the nucleus
rough ER
synthesis and transport of proteins to the golgi apparatus (mainly secretory proteins); contain ribosomes
smooth ER
synthesis and transport of lipids; drug detoxification
golgi apparatus
a stack of flattened membranous sacs which accepts, modifies, packages and ships protein products from the rough ER to various parts of the cell or out of the cell; transport of proteins is done in vesicles
lysosomes
contains enzymes that are involved in the digestion and breakdown of bacteria and old organelles
mitochondria
the site of energy production in the form of ATP
metabolism
sum of all chemical reactions
anabolic reactions
chemical reactions that build up; requires
catabolic reactions
chemical reactions that break large complex molecules to small building blocks; releases energy
phospholipids
form a bilayer where the polar heads face outwards towards extracellular environment and intracellular environment, nonpolar tails face each other
integral proteins
functions to transport specific molecules across the membrane
cholesterol
influence the fluidity of the membrane
glycoproteins/glycolipids
communication between cells
selectively permeable
some molecules can easily pass through, others cannot – depends on size and chemical properties
solvent
always water; material in which solutes are dissolved into
molecules moving down a concentration gradient…
are going from an area of high concentration to low concentration
molecules moving against a concentration gradient…
are going from an area of low concentration to high concentration
simple diffusion
passive movement of solute molecules from an area of high solute concentration to an area of low solute concentration; no energy required; molecules such as O2, CO2, fatty acids
facilitated diffusion
movement of molecules down a concentration gradient using a transport protein; no energy required; used in the cell to transport glucose, sodium ions, potassium ions
osmosis
movement of water
-movement is from the side with low solute concentration to high solute concentration
RBC in isotonic solution
no change in net difference
RBC in hypotonic solution
hemolysis (swell)
RBC in hypertonic solution
crenation (shrink)
active transport
movement of molecules across a membrane with the use of cellular energy (ATP); molecules can be moved against a concentration gradient; transport protein is required
example of active transport: Na+/K+ pump
sodium is maintained at high levels outside of cells, potassium at high levels inside cells
phagocytosis
type of endocytosis; an active process by with a cell can take in large pieces of solid material; important for destroying pathogens; done by specialized cells
pinocytosis
type of endocytosis; small molecules or droplets of fluid are taken up by the cell; done by most cells to uptake fluid and nutrients
exocytosis
reverse of endocytosis; molecules contained in vesicles in the cell are pushed out of the cell; controlled process to release molecules
