Objectives

●List scientists who contributed to the cell theory

●List the components of the cell theory

●Compare prokaryote and eukaryote cells

●Label a plant and an animal cell

●Know the functions of cell organelles

Early Contributions●Robert Hooke - First person to see cells, he was

looking at cork and noted that he saw "a great many

boxes. (1665)

●Anton van Leeuwenhoek - Observed living cells in

pond water, which he called "animalcules" (1673)

Leeuwenhoek saw these things in pond water.

●Theodore Schwann - zoologist who observed tissues of

animals had cells (1839)

●Mattias Schleiden - botanist, observed tissues of plants

contained cells ( 1845)

●Rudolf Virchow - also reported that every living thing is

made of up vital units, known as cells. He predicted that

cells come from other cells. (1850 )

The Cell Theory

1. Every living organism is made of one or more cells.

2. The cell is the basic unit of structure and function.

3. All cells arise from pre-existing cells.

*Why is the Cell Theory

called a Theory and not

a Fact?

Checkpoint

What was their contribution?

HookeLeeuwenhoekSchwannSchleidenVirchow

The Cell Theory

1. All living things are made of _____2. Cells are the basic unit of _______ and ______3. Cells come from _______________ cells.

Cell FeaturesALL cell have these parts

●Ribosomes – make protein for use by the organism

●Cytoplasm – fluid material within  cell

●DNA – genetic material

●Cytoskeleton – internal framework of cell

●Cell Membrane – outer boundary, some things can cross the cell membrane

Comprehension CheckpointAnswer true or false

1.Robert Hooke was the first person to see cells.

2.Bacteria cells have a cell membrane.

3.The Cell Theory was developed by a single scientist.

4.Plant cells have cytoplasm.

5.Cells taken from fungi do not have DNA.

6.Cells can only come from pre-existing cells.

7.It only took five years to develop the Cell Theory.

Prokaryote Cells●Simple cells

●Bacteria

●These cells do NOT have a nucleus, their DNA is

circular and floats in the cytoplasm

Some bacteria have a tail-

like structure called a

flagella, that helps it to

move.

A capsule surrounds

some bacteria and helps

them avoid the body’s

immune system

Bacteria Images

Bacteria that causes Anthrax

Eukaryotic CellsCells found in plants, animals, protists, and fungi The cell is composed of 4 main parts:

1.Cell membrane2.Cytoplasm3.Nucleus – “control center” of cell, DNA4.Organelles – small structures that carry

out specific functions (“little organs”)

Nucleus●Usually found at center of cell

●Has a nuclear membrane & nuclear pores

● Contains cell’s DNA in one of 2 forms

ochromatin - DNA and proteins, becomes...

ochromosomes - during cell division

  Nucleolus - which makes the cell’s ribosomes

True of False

1. All cells have a nucleus.

2. All cells have a cell membrane.

3. Eukaryote cells are the only cells to have a flagellum.

4. The nucleus contains the cell’s DNA.

5. Chromatin will become chromosomes.

6. The nucleolus makes the cell’s DNA.

Cell Organelles

Mitochondria – cell’s energy center; turns food

into a chemical energy called ATP

The mitochondria is sometimes called the

“powerhouse” of the cell

Cell Organelles

Golgi Apparatus (Body) – processes,

packages and secretes proteins. It is

comparable to a factory or a post office.

*A vesicle forms with Golgi to transport substances outside cell.  

Cell Organelles

Lysosome – Contains digestive enzymes,

breaks things down, "suicide sac”

Endoplasmic Reticulum – Transport, "intracellular highway".  -Rough ER contains many ribosomes & is involved in protein synthesis -Smooth ER no ribosomes

Cytoskeleton –

Helps cell maintain

support & shape; movement

a. microtubules- hollow tubes

b.  microfilaments-threadlike

c.  centrioles- only in animal cells;

used during cell division (paired) 

Vacuole – storage area for water and other

substaces, plant cells usually have a large

central vacuole

Protein Production

The cell is like a factory. Its product is protein which

goes to body to serve different functions.

1.DNA has instructions to build protein

2. Instructions are sent to ribosomes

3.The ribosomes build protein and sends it

through ER

4.The proteins go to golgi where they are packaged

for export

THE ANIMAL CELL

Cheek Cells Seen Through

Microscope

NAME THE PARTS

Plant Cells

●CELL WALL – provides additional support

●CHLOROPLASTS – contain green pigment,

photosynthesis

●CENTRAL VACUOLE – large water container

PLANT CELL

Can you identify

the parts?

Anacharis Cells Viewed With a

Microscope

Animal Cell vs Plant Cell 

CELL MEMBRANE●Selectively permeable ; it regulates what comes into

the cell and what leaves the cell

●It is composed of a double layer of phospholipids

with proteins embedded throughout