The Cell Theory!

Leeuwenhoek

▫Used a simple microscope▫First to see cells!

Robert Hooke

•Used a compound microscope•Looked at cork- saw•This reminded him of rooms in a

monastery so he called them “cells.”

T. Schwann

•Sounds like __________▫Swan!

•Concluded that all animals were made of cells.

M. Schleiden

•Concluded all plants were made of cells

Summary

*Hooke *Schwann *Schleiden Cells Animals Plants

All those scientists contributed to:•The Cell Theory

•What is a theory?

•A broad explanation that is testable, and has been proved by multiple researchers.

•Components of it can be changed or improved upon, without changing the overall truth of the theory as a whole.

First Part of the Cell Theory

•All living things are made of ▫cells

•They are either:▫Unicellular-

Consisting of only ONE cell▫Multicelluar-

Consisting of MANY cells.

Second Part of the Cell Theory •A cell is the basic unit of life.

•Cells•Tissue•Organ•Organ system •Organism!

•The beginning unit is always what?▫A CELL!

Third Part of the Cell Theory

•All cells come from pre-existing cells.

Muscle

Muscle

Muscle

Skin

Skin

Skin

Muscle

Muscle

Muscle

Muscle

INTRO TO CELLS

•You will need a separate sheet of paper to take additional notes.

•http://videos.howstuffworks.com/hsw/9699-cells-and-genetics-cell-theory-video.htm

•

Intro to Cells!

•Cell organelles:

•“tiny organs”

Most important• nucleus!

Organelles we will be very familiar with!• Nucleus**

▫ Nucleolus• Endoplasmic Reticulum (rough and smooth)• Ribosomes**• Golgi Apparatus• Lysosomes• Plasma (cell) membrane**• Vesicles• Mitochondria**• Cytoplasm (cytosol)• Cytoskeleton

▫ Centrioles• Vacuoles• Chloroplasts**• Cell Wall**

Two categories of cells:

•Prokaryotes•No nucleus•Majority are

unicellular•Simple- 1-2 organelles•1 job at a time•Bacteria (eu- and

archaea-)only

•Eukaryotes•Nucleus•Majority are

multicellular•Complex- 10-12

organelles•Good at Multitasking•Plants/animals/fungi/protists**THEY BOTH HAVE DNA AND

RIBOSOMES!!!**

PROKARYTIC CELLS LACK MEMBRANE BOUND

ORGANELLESEscherichia coli (E. coli)

Prokaryotic CellProkaryotic Cell

Animal

Plant

Fungi

Protist

Eukaryotic Cells

Semi (selectively) Permeable•Semi-

▫Some •Selectively-

▫ choosey

•Permeable- ▫allows to pass

•Selectively Permeable- ▫chooses what it allows to pass through

(Does this by active and passive transport).

Cell Membrane AKA “Plasma Membrane”AKA phospholipid bilayerThe outer boundary of a cell- skin

•Job:▫To maintain homeostasis

To regulate what goes in and out of a cell

•What is homeostasis?▫Internal balance- keeping things happy

PROTEIN MOLECULE LIPID

BILAYER

PROTEIN MOLECULE

CARBOHYDRATE

PROTEIN MOLECULE

Water- loving (outside of cell- touches water)

Water- fearing (inside of sandwich- never touches water)

A.

B.

POLAR HEADS

NONPOLARTAILS

Fluid Mosaic Model*

•Fluid Flexible•Mosaid different parts•Model representation

Function of:• Proteins in the membrane:

▫ Transport molecules in and out of the cell.

• Lipids in the membrane:▫ Creates a barrier between the cell and the watery

environment that is surrounding.

• Carbohydrates in the membrane:▫ Chemical signals and cell communication

•… HAVE DNA AS THEIR GENETIC MATERIAL (nucleus=euk or nucleoid=prok)

•… HAVE A CELL MEMBRANE

•… HAVE RIBOSOMES

•… HAVE CYTOPLASM

ALL CELLS…ALL CELLS…

•http://videos.howstuffworks.com/hsw/6051-cells-cell-walls-and-cell-membranes-video.htm