Luther Prep Biology Chapter 03

Front 1

active transport

Back 1

energy-requiring movement of molecules across a membrane from a region of lower concentration to a region of higher concentration

Front 2

cell membrane

Back 2

double layer of phospholipids that forma a boundary between a cell and the surrounding environment and controls the passage of materials

Front 3

cell theory

Back 3

theory that states that all organisms are made of cells, all cells are produced by other living cells, and the cell is the most basic unit of life

Front 4

cell wall

Back 4

rigid structure that gives protection, support, and shape to cells in plants, algae, fungi, and bacteria

Front 5

centriole

Back 5

small-cyinder shaped organelle made of protein tubes arranged in a circle; aids mitosis

Front 6

chloroplast

Back 6

organelle composed of numerous membranes that are used to convert solar energy into chemical energy; contains chlorophyll

Front 7

concentration gradient

Back 7

difference in the concentration of a substance from one location to another

Front 8

cytoplasm

Back 8

jelly-like substance inside cells that contains molecules and in some cells organelles

Front 9

cytoskeleton

Back 9

network of proteins, such as microtubules and microfilaments, inside a eukaryotic cell that supports and shapes the cell

Front 10

diffusion

Back 10

movement of dissolved molecules in a fluid or gas from a region of higher concentration to a region of lower concentration

Front 11

endocytosis

Back 11

uptake of liquids or large molecules into a cell by inward folding of the cell membrane

Front 12

endoplasmic reticulum

Back 12

interconnected network of thin, folded membranes that produce, process, and distribute proteins

Front 13

eukaryotic cell

Back 13

cell that has a nucleus and other membrane-bound organelles

Front 14

exocytosis

Back 14

release of substances out of a cell by the fusion of a vesicle with the membrane

Front 15

facilitated diffusion

Back 15

diffusion of molecules assisted by protein channels that pierce a cell membrane

Front 16

fluid-mosaic model

Back 16

model that describes the arrangement and movement of the molecules that make up a cell membrane

Front 17

Golgi apparatus

Back 17

stack of flat, membrane-enclosed spaces containing enzymes that process, sort, and deliver proteins

Front 18

hypertonic

Back 18

solution that has a higher concentration of dissolved particles compared with another solution

Front 19

hypotonic

Back 19

solution that has a lower concentration of dissolved particles compared with another solution

Front 20

isotonic

Back 20

solution that has an equal concentration of dissolved particles compared with another solution

Front 21

lysosome

Back 21

organelle that contains enzymes

Front 22

mitochondria

Back 22

bean-shaped organelle that supplies energy to the cell and has its own ribosomes and DNA

Front 23

nucleus

Back 23

organelle composed of a double membrane that acts as the storehouse for most of a cell's DNA

Front 24

organelle

Back 24

membrane-bound structure that is specialized to perform a distinct process within a cell

Front 25

osmosis

Back 25

diffusion of water molecules across a semipermeable membrane from an area of higher water concentration to an area of lower water concentration

Front 26

passive transport

Back 26

movement of molecules across the cell membrane without energy input from the cell

Front 27

phagocytosis

Back 27

uptake of a solid particle into a cell by engulfing the particle; see endocytosis

Front 28

phospholipid

Back 28

molecule that forms a double layered cell membrane; consists of a glycerol, a phosphate group, and two fatty acids

Front 29

prokaryotic cell

Back 29

cell that does not have a nucleus or other membrane-bound organelles

Front 30

receptor

Back 30

protein that detects a signal molecule and performs an action in response

Front 31

ribosome

Back 31

organelle that links amino acids together to form proteins

Front 32

selective permeability

Back 32

condition or quality of allowing some, but not all, materials to cross a barrier or membrane

Front 33

vacuole

Back 33

organelle that is used to store materials, such as water, food, or enzymes, that are needed by the cell

Front 34

vesicle

Back 34

small organelle that contains and transports materials within the cytoplasm