Chapter 7 Cells

Robert Hooke

used a mircroscope to examine a thin slice of cork and saw "little boxes". He called them "cells" because they looked like small rooms that monks lived in called Cells.

Anton Van Leeuwenhoek

a Dutch microscope maker who was the first to see living organisms while looking at pond water.

Matthias Schledien

German botanist who concluded that all plants are made of cells.

Theodor Schwann

German zoologist who concluded that all animals are made of cells.

Rudolph Virchow

German medical doctor who saw divivding cells in the microscope and reasoned that cells come from other cells.

Cell Theory

1. All living things are made of cells.
2. Cells are the basic unit of structure and function in and organism.
3. Cells come from the reproduction of existing cells.

Endosymbiotic Theory

American biologist Lynn Margulis privides evidence for the idea that certain organelles within cells were once free-living cells themselves

Levels of Organization

Atoms, Molecules, Organelles, Cells, Tissues, Organs, Organ Systems, Organism

Cell Specialization

cells in a mulit-cellur organism become specialized by turning different genes on and off.


specialized structure that performs important celluar functions within a eukaryotic cell. litterly means "little organ


the portion of the cell outside the nucleus, within the cell membrane.

nuclear envelope

layer of two membranes that surrounds the nucleus of a cell


granular material visible within the nucleus; consists of DNA tightly coiled around proteins.


threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next


small, dense region within most nuclei in which the assembly of proteins begins


small particle in the cell on which proteins are assembled; made of RNA and protein

endoplasmic reticulum

an internal membrane system in which components of cell membrane and some proteins are constructed

Golgi apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum


cell organelle filled with enzymes needed to break down certain materials in the cell


cell organelle that stores materials such as water, salts, proteins, and carbohydrates


cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use


organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy


network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement


one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope

cell membrane

thin, flexible barrier around a cell; regulates what enters and leaves the cell

cell wall

strong layer around the cell membrane in plants, algae, and some bacteria

lipid bilayer

double-layered sheet that forms the core of nearly all cell membranes


the mass of solute in a given volume of solution, or mass/volume


when particles tend to move from an area where they are more concentrated to an area where they are less concentrated


when the concentration of the solute is the same throughout a system


when water passes quite easily across most membranes, even though many solute molecules cannot


when the concentratin of two solutions is the same


when comparing two solutions, it has a greater concentraion of solutes


when comparing two solutions, it has less concentration of solutes

facilitated diffusion

when particles tend to move from an area where they are more concentrated to an area where they are less concentrated by using protein channels

active transport

energy-requiring process thatv moves material across a cell membrane against a concentration difference


the process of taking material into the cell by means of infoldings, or pockets, of the cell membrane


extensions of cytoplasm surround a particle and package it within a food vacuole


when tiny pockets from along the cell membrane, fill with liquid, and pinch off to form vacoules within the cell


when the membrane of the vacoule surrounding the material fuses with the cell membrane, forcing the contents out of the cell


threadlike structures made of a protein called actin


hollow structures made up of proteins known as tubulins


a group of similar cells that perform a particular function


groups of tissue working together

organ system

a group of organs working together to perform a specific function


when lysosome help digest unwanted cells


made of proteins called microtubules, help in cell movement (long)


made of proteins called microtubules, lets cell move itself (short)


DNA organized in a single chromosome, no nucleus ex. bacteria


Dna organized in mutiple chromosomes in side a nucleus, ex. animals and plants