C-Notes: Prokaryotes, Eukaryotes, and Viruses

Stnd: B.I. 1 C 10/30/2013

Objective: SWBAT differentiate the complexity and general structures of prokaryotic cells, eukaryotic cells, and viruses.

What is the “Cell Theory”?

• The idea that all living things are made up of cells.

3 parts of the Cell theory are:• All organisms are made up of one

or more cells• The cell is the basic (smallest)

unit of life• All cells come from pre-existing

cells.

What is the exceptions to the “Cell Theory”?

• Viruses – Disease-causing, nonliving particles– are not made up of cells and do NOT

contain genetic material (DNA).– Viruses reproduce inside another

cell, called the host cell.– Ex: HIV, Influenza, Common Cold,

Polioviruses, Rabies viruses

What are Cells?

• The smallest working units that is capable of performing all of life’s function

Where do Cells come from?

• All cells come from pre-existing cells through cell division (mitosis or meiosis).

Examples of Cells

Amoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

Would you like to see some examples?

Even if you don’t, too bad.

Remember…

• These are magnified images taken with microscopes

• Some cells have been stained with color so you can see them better.

Nerve Cell

Bacteria Cell

Tree cells from the stomach of a possum.

Brain Cell

Cornstalk Cells

Mammalian Tissue

Who is Robert Hooke?

• The first person to see cells using a thin slice of cork found in the bark of a cork tree with his microscope.

• He named them cells because they resembled tiny rooms

What are the two types of Cells?

• Prokaryotic Cells • Eukaryotic Cells

What are Prokaryotic Cells? (Before the Nucleus)

1. Found in Unicellular Organism (Single-Celled Organism)– Do NOT have a nucleus to

hold its circular DNA molecule (nucleoid), so the DNA remains to float freely in the cytoplasm.

– Ex: Bacteria and Blue-Green Algae (Cyanobacteria)

Prokaryote cells are simply built (example: E. coli)

• capsule: slimy outer coating

• cell wall: tougher middle layer

• cell membrane: delicate inner skin

• cytoplasm: inner liquid filling• DNA in one big loop• pilli: for sticking to things• flagella: for swimming• ribosomes: for building

proteins

Prokaryote cells are simply built (example: E. coli)

Prokaryote lifestyle

• unicellular: all alone

• colony: forms a film

• filamentous: forms a chain of cells

Prokaryote Feeding

• Photosynthetic: energy from sunlight• Disease-causing: feed on living things• Decomposers: feed on dead things

What are Eukaryotic Cells? (After the Nucleus)

–Found in Multi-Cellular Organism called Eukaryotes–contains many organelles

surrounded by membranes –Store their DNA in the

Nucleus–Ex: plants and animals

Eukaryotes are bigger and more complicated

• Have organelles• Have chromosomes• can be multicellular• include animal and plant cells

Organelles are membrane-bound cell parts

• Mini “organs” that have unique structures and functions

• Located in cytoplasm

Eukaryotic• Contain organelles surrounded by membranes• Most living organisms

Plant Animal

http://library.thinkquest.org/C004535/eukaryotic_cells.html

“Typical” Animal Cell

“Typical” Plant Cell

What are the complexity and structural components of Prokaryotic Cells and Eukaryotic Cells?

1. Unicellular (Single-Celled Organism)

2. Cell Wall that surrounds the Cell (Plasma) Membrane

3. Has DNA, RNA, and Ribosomes that float freely in the cell.

4. No NUCLEUS has a Cellular DNA ( Nucleus-Like, irregularly shapped)

5. Flagellum (Tail, for movement)

6. Reproduces Asexually, binary fission (divide in half) , Conjugations ( connects and exchange DNA)

1. Multi-Cellular Organism (10x larger in size)

2. Cell Membrane3. Cell Wall (only in plants)4. Ribosomes5. Contains a Nucleus (has

DNA inside)6. Contains many

Membrane-Bounded Organelles (Tiny structural Bodies ; ex: chloroplast; mitochondria) for certain jobs

7. Growth and Replication by Mitosis and Meiosis.

Prokaryotic Cells found in Prokaryotes (ex: Bacteria)

Eukaryotic Cells found in Eukaryotes (Ex: plants and Animals)

What are the 3 structures that are both Eukaryotic and Prokaryotic Cell have?

1. Cell Membrane 2. Cytoplasm (jelly-like fluid

“soupy” area)3. DNA (found in the Nucleus in

Plants and Animal Cells)

Advantages of each kind of cell architecture

Prokaryotes Eukaryotes

simple and easy to grow can specialize

fast reproduction multicellularity

all the same can build large bodies