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