Chapter 3 Human Anatomy and Physiology
phospholipid heads vs tails
Phospholipids consist of a hydrophilic (or 'water loving') head and a hydrophobic (or 'water fearing') tail... A single phospholipid molecule has a phosphate group on one end, called the "head," and two side-by-side chains of fatty acids that make up the lipid "tails
solute pumping (Na/K pump)
a form of active transport of a solute through a cell membrane, allows a molecule that cannot regularly cross the lipid bilayer to enter the cell by way of a protein channel
plasma membrane
a fragiles transparent barrier that contains the cell contents and seperates them from the surrounding enviroment , selectively permeable
nucleolus
a small dense spherical structure in the nucleus of a cell during interphase
hypotonic
a solution contains fewer solutes than the cell does
hypertonic
a solution that contains more solutes or dissolved substances than there are inside the cell
glycoprotiens
any of a class of proteins that have carbohydrate groups attached to the polypeptide chain
mitochondria
converts energy from food to energy the cell can use
concentration gradient
difference in concentration of a dissolved substance in a solution between region of high density and one of lower density
osmosis
diffusion of water through a selectively permeable membrane such as the plasma membrane
nuclear envelope
double membrane barrier bounding the nucleus
peroxisomes
enzymes detoxify a number of toxic substances
protein channels
facilitate the transport of substances across a cell membrane, through the process of either facilitated diffusion or active transport depending on the concentration gradient, or the difference in the concentration of substances inside and outside the cell membrane
ribosomes
grain like , produce proteins
rough ER
grain like and produces proteins
isotonic
have the same solute + water concentrations as cells do
pinocytosis
he ingestion of liquid into a cell by the budding of small vesicles from the cell membrane
vesicular transport
involves help from ATP, moves substances into or out of cells without their actually crossing the plasma membrane
nuclear pores
large protein complexes that cross the nuclear envelope
passive transport
movement of substances across cell membranes without needing energy
diffusion
process by which molecules move away from a region where they are more concentrated to a region where they are less concentrated
filtration
process by which water and solutes are forced through a membrane by fluid, or hydrostatic, pressure
facilitated diffusion
process of spontaneous passive transport of molecules or ions across a membrane via specific transmembrane integral proteins
protein pumps
proteins have to work against a concentration gradient, pumping something (usually ions) from areas of lower to higher concentration.
lysosome
release chemicals that break down large food particles into smaller ones
chromatin
scatterted throughout the nucleus, its DNA is combined with protein+ forms a loose network of bumpy threads
golgi apparatus
sends and recieves material in cell
smooth ER
site of lipid and steroid synthesis
nucleus
the cell headquarters, the control center
cytoplasm
the cellular material outside the nucleus and inside the plasma membrane
phagocytosis
the ingestion of bacteria or other material by phagocytes and amoeboid protozoans
active transport
the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy
protein carriers
the movement of ions, small molecules, or macromolecules, such as another protein, across a biological membrane
flagella
the projections formed by the centrioles are substanially longer
endocytosis
the taking in of matter by a living cell by invagination of its membrane to form a vacuole
cell junctions
tight junctions: impermeable junctions that encircle the cells+bind them together into leakproof sheets Desmosomes: anchoring junctions Gap junctions: to allow communication, connected by connexons
microvilli
tiny, fingerlike extensions of the plasma membrane that project from an exposed cell surface
exocytosis
type of vesicular transport... moves substances out of cells
cilia
whiplike cellular extensions that move substances along the cells surface