The Cell

I. Cell Theory

A. Early 1600s - Compound microscope

invented

1. Made it possible for people to discover and learn about cells

B. Famous Scientists

a. English physicist

b. Observed cork cells

c. Cork is made of many small chambers he called “cells” (after monastery rooms)

d. Inspired other scientists to search for cells in organisms

1. Robert Hooke (1665)

a. Dutch businessmanb. First person to see tiny organisms in a drop of water (called them “animalcules”)

c. First person to see bacteria

2. Anton van Leeuwenhoek (1674)

3. Matthias Schleiden (1838)a. German botanist

(plant specialist)

b. Concluded that

All plants are made of cells

Not to be confused with…

cellscells

Sideburns

4. Theodore Schwann (1839)

a. German scientist

b. Concluded that all animals are made of cells

a. German physician

b. Realized that all cells come from pre-existing cells

5. Rudolf Virchow (1855)

The Cell Theory

1.All living things are made up of cells.

2.The cell is the basic unit of function in living things.

3. All cells come from pre-existing cells.

C. The discoveries of these scientists lead to the formation of the Cell Theory:

***DON’T FORGET:

Tissue

Organ System

Organ

Organism

Cell

Organelle

(group of similar cells)

II. Prokaryotes vs. Eukaryotes

CELLS

Prokaryotic Eukaryotic

• No True Nucleus- Genetic material is free-floating in Cytoplasm

• No specialized organelles • Contain specialized organelles

• True Nucleus- Genetic material is bound by a membrane

EX: Bacteria EX: Human Cells

Smaller Larger

Animal Cell

Plant Cell

Cell wall

III. Cell Structures & OrganellesStructure Found in… Function Other Important Info

Cell Wall Plants, Fungi and Prokaryote

NOT Animal Cells

•Support & protection

•Lies outside cell membrane•Prokaryotes – peptidoglycan •Fungi – chitin•Plants – cellulose

Cytoplasm All cells

•Contains important structures (organelles)

• Fluid-like material (mostly H2O) found inside cell between membrane and nucleus

Cell Membrane

All cells •Regulates what enters/ leaves the cell (selectively permeable)

•Composed mainly of lipids and proteins

Structure Found in… Function Other Important Info

Nucleus All Eukaryotic

Cells

• Controls most cell processes

•Contains hereditary information (DNA)

• Parts of/in the nucleus:a) Nuclear

Envelope/Membrane: porous double membrane surrounding the nucleus (allows materials in/out of nucleus)

b) Chromatin : granular material made up of DNA wrapped around protein(condenses into thread-like chromosomes during cell division)

c)Nucleolus: small, dense region where ribosomes are produced

nuclear pores

chromatin

nucleolusNuclear poreNucleolus

Chromatin

Nuclear envelope

Structure Found in… Function Other Important Info

Endoplasmic Reticulum

All Eukaryotic

Cells

•Components of cell membrane assembled•Proteins modified•Pathway for material transport

Smooth ER (No ribosomes)= 2 Types of E.R.

Rough ER (Ribosomes attached) =

•Synthesis of lipids(fat)•Metabolize carbs

•Detox of drugs and poisons

•Protein production & storage

Ribosome All cells **THE SITE OF PROTEIN

SYNTHESIS**

•Located on Rough ER and Suspended in Cytoplasm

Endoplasmic reticulum

Endoplasmic ReticulumNucleus

Structure Found in… Function Other Important Info

Golgi Complex

All Eukaryotic

Cells

•Attach carbohydrates and lipids to proteins•Packages and ships materials throughout cell in transport vessels

•Stacks of flat membrane sacs •Produces some polysaccharides

Lysosome All Animal Cells,

NOT Plant and

Prokaryotic Cells

•Breaks down food and old organelles

•Destroys foreign material/bacteria

•Small membrane sac containing digestive enzymes.

Structure Found in… Function Other Important Info

VacuoleAll Plant

cells (Large), Animal cells

(small or none),

NOT in Prokaryotes

•Storage vessel for …

FoodWaterWasteCell Products

Contractile Vacuole Pumps excess water out of cell

Structure Found in… Function Other Important Info

All Eukaryotic

Cells

•Cell movement

Microtubules

•Found in the cytoskeleton, which provides support to the cell’s shape•Serve as “tracks” for organelles to move

•Helps build other structures...

-Centrioles

-Cilia-Flagella

Hair-like organelles involved in cell movement

•Cylinder-like structures made of tubulin

•Chromosome movement

The eukaryotic cytoskeleton: Microfilaments in red; Microtubules in green; Nuclei in blue

Cilia

Flagella

Structure Found in… Function Other Important Info

Microfilament

All Eukaryotic

Cells

•Aid in the movement of cytoplasm within the cell Cyclosis•Found in the cytoskeleton (support)

•Thread-like strands of actin in the cytoplasm

Centrioles Animal Cells Only

• Help separate chromosomes during cell division

•Pair of cylinders (made of microtubules) that lie at right angles to each other

Structure Found in… Function Other Important Info

Mitochondria

All Eurkaryotic

Cells

•Has a double membrane: inner membrane is folded to increase surface area for biochemical reactions

** Have their own DNA and can duplicate themselves**

“Powerhouse”

•Release energy from stored food molecules (glucose) •Produce ATP through aerobic respiration

Structure Found in… Function Other Important Info

Chloroplast

Photosynthetic cells ONLY,

NOT in Animal Cells or

Prokaryotes •Protein rich fluid called stroma

Contains...• Use energy from sunlight to make energy-rich food molecules (glucose)

• Produce oxygen

•Stacks of thylakoid membranes called grana

•Chlorophyll (green)

*Have their own DNA and can duplicate themselves

*Endosymbiotic Theory-

Mitochondria and chloroplasts are thought to have evolved from bacteria that were engulfed by larger cells.

*Endosymbiosis-One organism lives inside the cell of another organism to the benefit of both.

Animal CellA

H

G

FE

B

D

C

Plant Cell

A

G

BCD

E

F

Animal Cell

cytoplasm

vacuole cell membrane

ribosomes

lysosome

golgi body

mitochondrionendoplasmic

reticulumnuclear membrane

nucleolus

chromatin

nucleus

Plant Cell

cytoplasm

vacuole cell membrane

cell wall

ribosomes

chloroplast

golgi bodymitochondrionendoplasmic

reticulumnuclear membrane

nucleolus

chromatin

nucleus