Cytology Terminology

cell

smallest unit of all living things

cell membrane

surrounds cells; composed of protein and lipids; protects the inside of cells; supports cell; selectively permeable (like a window screen)

nucleus

control center" of the cell; contains instructions for cell activities

nuclear membrane

encloses nucleus; allows passage of materials in and out of nucleus

nucleolus

found in nucleus; contains protein and nucleic acids (RNA)

dexoyribonucleic acid

DNA- genetic material

ribonucleic acid

RNA

chromosomes

contain genes (coded instructions)

mitochondria

powerhouse of a cell"; provide energy; release energy in food; produces ATP

cristae

folded inner membrane of mitochondria that contains enzymes

cell respiration

releases carbon dioxide adn water, which are used to make glucose

adenosine triphosphate

ATP - energy storage molecule

cytoplasm

protoplasm" - jelly-like material within a cell containing organelles

vacuole

store food and water; store wastes and help excrete them

centrioles

only in animal cells; form spindle in mitosis

chloroplasts

contains chlorophyll and cartenoids

organelle

small organ-like parts of the cell

prokaryotic

before the nucleus"; no nuclear membrane or organelles

eukaryotic

nuclei with membrane; plant/animal cells

pinocytosis

cell drinks

phagocytosis

cell eats

selectively permeable

allowing things in and out

endoplasmic reticulum

a network of canals which run throughout the cytoplasm; transports materials throughout a cell

specialization

different cells do different things

lysosomes

break down waste products and food molecules

ribosomes

site of protein synthesis; sometimes found free in cytoplasm

golgi apparatus

center of manufacturing and shipping

cell wall

rigid structure surrounding membrane - found only in plant cells

enzymes

proteins which speed up chemical reactions without being used up

Anton van Leeuwenhoek

Dutch shopkeeper who looked at pondwater; observed "animalcules"-single celled organisms; first person to see living cells

Robert Hooke

English scientist who looked at cork cells and observed tiny boxes -cells "litte rooms"; coined the term "cell

Matthias Schleidan

German botanist who noticed all plants seemed to be made of tiny units (cells)

Theodor Schwann

German scientist who observed animal tissue and stated that cells were the building blocks of both plants and cells; said there are different kinds of cells but similarities between plant and animal cells

Rudolf Virchow

German physician who concluded that cells are produced only by other living cells

Cell Theory

all living things are made up of 1 or more cells; cells are the basic units of structure and function in living things; all cells come only from other living cells

mitosis

cell reproduction

organic

composed of Carbon and Hydrogen

chloroplasts

found only in PLANT cells; produce chlorophyll and carotenoids; used in photosynthesis

passive transport

movement of substances through the cell membrane without the input of energy

diffusion

movement of molecules from an area where there is more of them into an area where there is less of them (moving from greater to lesser concentration)

concentration

amount of a substance in a particular area

facilitated diffusion

uses transport proteins to move small molecules across the cell membrane

osmosis

diffusion of WATER through a selectively permeable membrane

isotonic

equal amount of solutes and solvent inside and outside of the cell

hypotonic

concentration of solute inside cell is higher than outside cell - water moves into cell using osmotic pressure

hypertonic

concentration of solute outside cell is higher than inside cell - water flows out of the cell