Biology Chapter 7

Front 1

cell

Back 1

basic unit of structure and organization of all living organisms

Front 2

cell theory

Back 2

states that organisms are made of one or more cells; cells are the basic unit of life; and all cells come only from other cells

Front 3

plasma membrane

Back 3

flexible, selectively permeable boundary that helps control what enters and leaves the cell

Front 4

organelle

Back 4

specialized internal cell structure that carries out specific cell functions such as protein synthesis and energy transformation

Front 5

eukaryotic cell

Back 5

a cell with a membrane-bound nucleus and organelles; generally larger and more complex than a prokaryotic cell

Front 6

nucleus

Back 6

center of an atom; contains neutrons and protons. in eukaryotic cells, the central membrane-bound organelle that manages cellular functions and contains DNA

Front 7

prokaryotic cell

Back 7

a cell without a nucleus or other membrane-bound organelles

Front 8

selective permeability

Back 8

property of the plasma membrane that allows it to control movement of substances into or out of the cell

Front 9

phospholipid bilayer

Back 9

plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and non polar tails facing the inside

Front 10

transport protein

Back 10

protein that moves substances or wastes through the plasma membrane

Front 11

fluid mosaic model

Back 11

a plasma membrane with components constantly in motion, sliding past one another within the lipid bilayer

Front 12

cytoplasm

Back 12

semifluid material inside the cell's plasma membrane

Front 13

cytoskeleton

Back 13

supporting network of protein fibers that provide a framework for the cell within the cytoplasm

Front 14

ribosome

Back 14

simple cell organelle that helps manufacture proteins

Front 15

nucleolus

Back 15

the site of ribosome production within the nucleus of eukaryotic cells

Front 16

endoplasmic reticulum

Back 16

highly folded membrane system in eukaryotic cells that is the site for protein and lipid synthesis

Front 17

Golgi apparatus

Back 17

flattened stack of tubular membranes that modifies, sorts, and packages proteins into vesicles and transports them to other organelles or out of the cell

Front 18

vacuole

Back 18

membrane-bound vesicle for temporary storage of materials such as food, enzymes, and wastes

Front 19

lysosome

Back 19

vesicle that uses enzymes to digest excess or worn-out cellular substances

Front 20

centriole

Back 20

organelle that plays a role in cell division and is made of microtubules

Front 21

diffusion

Back 21

net movement of particles from an area of higher concentration to an area of lower concentration

Front 22

dynamic equilibrium

Back 22

condition of continuous, random movement of particles but no overall change in concentration of materials

Front 23

facilitated diffusion

Back 23

passive transport of ions and small molecules across the plasma membrane by transport proteins

Front 24

osmosis

Back 24

diffusion of water across a selectively permeable membrane

Front 25

isotonic solution

Back 25

a solution with the same concentration of water and solutes as inside a cell, resulting in the cell retaining its normal shape because there is no net movement of water

Front 26

hypotonic solution

Back 26

a solution that has a lower concentration of solute outside than inside the cell, causing water to flow into the cell by osmosis

Front 27

hypertonic solution

Back 27

a solution that has a higher concentration of solute outside than inside a cell, causing water to leave the cell by osmosis

Front 28

active transport

Back 28

energy-requiring process by which substances move across the plasma membrane against a concentration gradient

Front 29

endocytosis

Back 29

energy-requiring process by which large substances from the outside environment can enter a cell

Front 30

exocytosis

Back 30

energy-requiring process by which a cell expels wastes and secretes substances at the plasma membrane

Front 31

mitochondrion

Back 31

membrane-bound organelle that converts fuel into energy that is available to the rest of the cell

Front 32

chloroplast

Back 32

double-membrane organelle that captures light energy and converts it to chemical energy through photosynthesis

Front 33

cell wall

Back 33

in plants, the rigid barrier that surrounds the outside of the plasma membrane, is made of cellulose, and provides support and protection to the cell

Front 34

cilium

Back 34

short, hairlike projection that functions in cell movement

Front 35

flagellum

Back 35

long, tail-like projection with whiplike or propeller motion that helps a cell move