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when molecules move from an area of high concentration to an area of low concentration

Cell Wall

a relitivly inflexible structure that surrounds the plasma membrane


located in the nucleus and produces tiny cell particles that are involved in protein synthesis called RIBOSOMES


organelles in which food molecules are broken down to release energy


transform light energy into useable chemical energy and store it in food molecules


contains the cell's DNA and manages the cell's functions

Cell/Plasma Membrane

a boundry between the cell and its external environment


clear fluid in eukaryotic cells surrounding the nucleus and other organelles

Endoplasmic Reticulum (ER)

folded, complex system of membranes forming a type of transport system in the cytoplasm of eukaryotic cells

Golgi Appartus vacuole

membrane sacs that receive, chemically modify, and repackage proteins into forms the cell can use, expel, or keep stored


membrane-bound organelles containing enzymes that digest food particles, viruses and bacteria, worn-out cell parts, and sometimes the cell itself


organic compounds commonly called fats and oils; insoluble in water, lipids are the major components of membranes surrounding all living cells


eukaryotic organelles that are involved in protein synthesis


the diffusion of water molecules through a selectively permeable membrane form an area of higher concentration to and area of lower water concentration

What was Darwin's theory of Natural Selection?

heritable variation+competition+selective pressure=natural selection


proteins that accelerate chemical reactions but do not change themselves in the reaction; enzymes enable molecules to undergo chemical change, forming new subatnaces called products


cell having a true nucleus and membrane-bound internal organelles


cell lacking a true nucleus or membrane-bound internal organelles


cell structure that caries the genetic material


cell structure that joins two sister chromatids of a chromosome.


cell division during which chromosomes are equally distributed to the two identical daughter cells that are formed; results in growth


thin fiber structure that forms between the two poles or centioles during prophase and shortens during anaphanse, pulling the sister chromatids apart

active transport

process requiring energy by which cells move materials against a concentraton gradient

passive transport

in cells, movement across cell membranes requiring no expenditure of energy by the cell; ex. diffusion and osmosis

facilitated diffusion

passive transport of materials, such as sugars and amino acids, across the plasma membrane by way of transport proteins


active transport process by which materials are expelled or secreted from a cell

hypotonic solution

in cells, solution in which the concentration of dissolved materials is lower in the solution surrounding the sell than the concentration inside the cell, which will swell and possibly burst as water enters the cell by osmosis

isotonic solution

solution in cells which disolved materials and water occur in the same concentration as inside the cell

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