quiz notes
chromsomes
are only formed when a cell divides; contains the genetic information that is passed from one generation to the next
chloroplasts
biological equivalents of solar power plants. they capture energy from sunlight & convert iti to food that contains chemical energy in a process called photosynthesis.
ribosomes
cell structure where proteins are made. they are synthesized in the nucleus.
nuclear membrane
composed of 2 membranes that controls the exchange of substences between the nucleus and the cytoplasm
nucleus
contains DNA; controls cell activity
mitochondria
converts chemical energy stored in food into conpounds that are more conveient for the cell to use
osmosis
diffusion of water through a selectively permable membrane
cytoplasm
fluid portion of cells outside the nucleus. site of numerous chemical reactions
osmotic pressure
force exerted by the net movement of water in or out of a cell.
lipid bilayer
gives cell membrandes a flexible structure that forms a strong barrier between the cell & its surroundings.
water moves towards blank solute concentration
higher
microtubules
hollow structure made up of proteins known as tubulins.
hypotonic
indicates a higher concentration of solute inside a cell water diffuses in then the cell swells
isotonic
indicates that the concentration of a solute is the same on both sides of the cell membrane. no net change in the cell
hypertonic
indicates that the concentration of solute is higher outside the cell. the water diffuses out and the cell shrinks
endoplasmic reticulum (ER)
internal membrane system where lipid compnets of the cell membrane are assembled. along with proteins and other materials that are exported from the cell.
vacuoles
large, sac-like membrane. enclosed structure that stores materials
centrioles
located near the nucleus and help to organize cell division
golgi apparatus
modifies, sorts & packages proteins & other materials from the ER for storage in the cell or release outside the cell.
selectively permeable
most biological membranes are s.p. meaning some substances can pass across them & others cant.
passive transport
movement of materials across the cell membrane without using energy
cytoskeleton
network of protein filaments which give cells their shape and internal organization
nucleolus
organelle where the assembly of ribosomes begins
falilitated diffusion
process by which molecules that cannot directly diffuse across membranes pass (diffuse) through special protein channels.
diffusion
process by which particles move form an area of high concentration to an area of lower concentration
cell membrane
regulates what enters and leaves the cell. made of lipids, proteins and some carbohydrates. mostly lipids and phospholipids.
lysosomes
small organelles filled with digestive enzymes that function as the cells' cleanup crew
vesicles
smaller membrane-enclosed structures used to store an move materials between cell organelles, as well as to and from the cell surface.
cell wall
strong suporting layer around membrane
microfilaments
the readlike structures made up of a protein called actin. it supports the cell and aid in cell movement.
aquaporins
water channel protein in a cell
