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.
organelle
specialized structure that performs important celluar functions within a eukaryotic cell. litterly means "little organ
cytoplasm
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
chromatin
granular material visible within the nucleus; consists of DNA tightly coiled around proteins.
chromosome
threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next
nucleolus
small, dense region within most nuclei in which the assembly of proteins begins
ribosome
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
lysosome
cell organelle filled with enzymes needed to break down certain materials in the cell
vacuole
cell organelle that stores materials such as water, salts, proteins, and carbohydrates
mitochondrion
cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use
chloroplast
organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy
cytoskeleton
network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement
centriole
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
concentration
the mass of solute in a given volume of solution, or mass/volume
diffusion
when particles tend to move from an area where they are more concentrated to an area where they are less concentrated
equilibrium
when the concentration of the solute is the same throughout a system
osmosis
when water passes quite easily across most membranes, even though many solute molecules cannot
isotonic
when the concentratin of two solutions is the same
hypertonic
when comparing two solutions, it has a greater concentraion of solutes
hypotonic
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
endocytosis
the process of taking material into the cell by means of infoldings, or pockets, of the cell membrane
phagocytosis
extensions of cytoplasm surround a particle and package it within a food vacuole
pinocytosis
when tiny pockets from along the cell membrane, fill with liquid, and pinch off to form vacoules within the cell
exocytosis
when the membrane of the vacoule surrounding the material fuses with the cell membrane, forcing the contents out of the cell
microfilaments
threadlike structures made of a protein called actin
micrortubles
hollow structures made up of proteins known as tubulins
tissue
a group of similar cells that perform a particular function
organ
groups of tissue working together
organ system
a group of organs working together to perform a specific function
apotosis
when lysosome help digest unwanted cells
flagella
made of proteins called microtubules, help in cell movement (long)
cilia
made of proteins called microtubules, lets cell move itself (short)
prokaryote
DNA organized in a single chromosome, no nucleus ex. bacteria
eukaryote
Dna organized in mutiple chromosomes in side a nucleus, ex. animals and plants