Science Unit One

Front 1

unicellular

Back 1

consisting of a single cell

Front 2

multicellular

Back 2

consisting of many cells

Front 3

prokaryotic cell

Back 3

cell lacking a nucleus and most other organelles

Front 4

eukaryotic cell

Back 4

cell with a nucleus (surrounded by its own membrane) and other internal organelles

Front 5

cell membrane

Back 5

thin outer boundary of a cell that regulates the traffic of chemicals between the cell and its surroundings

Front 6

Selectively permeable membrane

Back 6

membrane that allows some substances to pass more easily than others and blocks the passage of some substances altogether

Front 7

Diffusion

Back 7

net movement of the particles of a substance from where they are more concentrated to where they are less concentrated

Front 8

Facilitated Diffusion

Back 8

Pathway provided by transport proteins that helps certain molecules pass through a membrane

Front 9

osmosis

Back 9

passive transport of water across a selectively permeable membrane

Front 10

Passive Transport

Back 10

diffusion across a membrane requiring only the random motion of molecules with no energy expended by the cell

Front 11

active transport

Back 11

movement of molecules across a membrane requiring energy to be expended by the cell

Front 12

endocytosis

Back 12

process of taking material into a cell within vesicles that bud inward from the plasma membrane

Front 13

exocytosis

Back 13

process of exporting proteins from a cell by a vesicle fusing with the plasma membrane

Front 14

concentration

Back 14

the amount of solute per unit volume of solution

Front 15

hypotonic

Back 15

having a lower concentration of solute than another solution (more dilute)

Front 16

hypertonic

Back 16

having a higher concentration of solute than another solution

Front 17

isotonic

Back 17

having a solute concentration equal to that of another solution

Front 18

cytoplasm

Back 18

region of a cell between the nucleus and the plasma membrane

Front 19

nucleus

Back 19

In a cell, the part that houses the cell's genetic material in the form of DNA

Front 20

Cell wall

Back 20

strong wall outside a plant cell's plasma membrane that protects the cell and maintains its shape

Front 21

mitochondria

Back 21

cellular organelles where cellular respiration occurs

Front 22

chloroplasts

Back 22

organelle found in some plant cells and certain unicellular organisms where photosynthesis takes place

Front 23

ribosomes

Back 23

cluster of proteins and nucleic acids that constructs proteins in a cell

Front 24

Golgi Apparatus

Back 24

cellular organelle that modifies, stores, and routes cell products

Front 25

Endoplasmic Reticulum

Back 25

network of membranes within a cell's cytoplasm that produce a variety of molecules

Front 26

Vacuoles

Back 26

membrane-bound sac that buds from the endo-plasmic reticulum or the Golgi apparatus

Front 27

Vesicles

Back 27

small membrane-bound sac that functions in moving products into, out of, and within a cell

Front 28

Lysosomes

Back 28

membrane-bound sac containing digestive enzymes that can break down proteins, nucleic acids, and polysaccharides