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