CELL THEORY, STRUCTURE &

FUNCTION

History of Cells• Robert Hooke (1665) observed cork under a

microscope

• Thought they looked like the rooms monks lived in called cells.

History of Cells

• Antony Van Leeuwenhoek (1683)

– first recorded observations of single-celled, animal-like creatures(animalcules)

Courtesy of: http://www.ucmp.berkeley.edu

Early Cell Theories

• Redi: spontaneous generation

• Pasture: theory of biogenesis

• Oparin – Haldane: primordial Soup and the Miller – Urey experiment

1) All living things are composed of cells. (Schleiden and Schwan 1838)

2) Cells are the basic units of structure and function in living things. (Schleiden and Schwan 1838)

3) New cells are produced from existing cells. (Virchow 1855)

Cell Theory

Microscope Technology

• Compound Light Microscope: 100x

• Electron Microscope: 500,000x

• Scanning Electron Microscope (SEM): 3-D images

What do all cells have in common?

• Genetic material

• Ribosomes

• Cytoplasm

• Plasma membrane

Pro=NOEu=TRUE

• Prokaryotes= NO nucleus

• Eukaryotes= Have a TRUE nucleus

With your partner, make a list of the similarities and difference of these two cells.

2 Cell Types1. PROKARYOTES• “before nucleus” = NO

NUCLEUS!

• Small and simple

• No membrane bound organelles

• Unicellular

• Ex: Eubacteria and archaea

2. EUKARYOTES• “true nucleus”= Has a

nucleus!

• Large and complex (greater adaptability)

• Yes! membrane bound Organelles

• Unicellular or multicellular

• Ex: animals, plants, fungi, protists

• Turn to your shoulder partner and tell them:

–Partner 1: “Prokaryotic cells are different from Eukaryotic cells because _________________________.”

–Partner 2: “I agree/disagree with you because _________________________.”

Complexity of Cells and the Endosymbiotic Theory

One prokaryotic cell engulfed another

smaller prokaryotic cell…

Endo- “in”Symbiosis- interaction of two organisms living togetherTherefore the theory states that organelles found in eukaryotic cells came from preexisting prokaryotic cells.

Thumbs Down - prokaryotic

Thumbs Up - eukaryotic

Prokaryotes vs. Eukaryotes

Prokaryotes vs. Eukaryotes

Prokaryotes vs. Eukaryotes

Prokaryotes vs. Eukaryotes

Prokaryotes vs. Eukaryotes

Prokaryotes vs. Eukaryotes

Membrane Bound Organelles…

A science-y way of saying that eukaryotic cells have

“organs” just like the human body has organs!

Each organelle has a separate function….

Organelle #1: Cell Membrane =

phospholipid bilayer = Plasma Membrane

• Seen in all cells!

• isolates the cell contents from the environment

• regulates movement of materials into and out of the cell (semipermeable or selectively permeable membrane)

Far

away

Up

close

#2 Nucleus

• control center for cells

• contains DNA and chromosomes

• only in eukaryotes

#3 Ribosomes• Site of protein synthesis: the

creation of proteins.

• What monomers are these

Ribosomes linking together to

create these proteins?!

#4 Endoplasmic Reticulum

• Rough ER

– Protein Synthesis

– Covered in ribosomes

– In all eukaryotic cells

• Smooth ER

– Lipid production

– In all eukaryotic cells

#5 Golgi Body/Apparatus

• Packaging and transport of proteins made by the ribosomes

• In all eukaryotic cells

#6 Vacuole

#7 Mitochondria• Produce ATP (energy)

by cellular respiration

• “Powerhouse” of the cell

#8 Chloroplast

• Essential for photosynthesis

• Plants use sunlight energy to convert carbon dioxide and water to glucose & oxygen

• contains Chlorophyll(pigment that absorbs sunlight)

• PLANTS only

• Has its own DNA

#9 Lysosomes• Purpose: digestion for

the cell.

• A membrane bound organelle (only in animals) containing various enzymes.

• The lysosome is created by the endoplasmic reticulum. It then floats in the cytoplasm of a cell until it is needed.

#10 Cell Wall

• Protects and supportsthe cell

• Absent in animal cells (present in all other types of cells)

• Made of cellulose (carbohydrate)

Courtesy of:http://www.google.com/imgres?imgurl=http://biology.unm.edu

Plants vs. Animals

Comparing Cells pg. 199

• Nucleus

• Nucleolus

• Nuclear envelope

• Chromatin & Chromosomes

• Ribosomes

• Rough Endoplasmic reticulum (rough ER)

• Smooth Endoplasmic reticulum (smooth ER)

• Cilia

• flagella

• Golgi Apparatus

• Lysosomes

• Vacuole

• Mitochondria

• Chloroplasts

• Cytoskeleton

• Cell membrane

• Cell Wall

• Centrioles