Eukaryotic Cells vs. Prokaryotic Cells

Eukaryotic and Prokaryotic cells Key Question- What is the difference between a Eukaryotic and Prokaryotic cell? Initial Thoughts-

What is a Cell? Cell – Basic unit of living things. Organisms are either: Unicellular – made of one cell such as bacteria and amoebas. OR Multicellular – made of many cells such as plants and animals.

Cell Theory The cell theory states that:  All living things are made of one or more cells.  Cells are the basic unit of structure and function in living things.  All cells come from other cells.

The Discovery of Cells before nucleus true nucleus

Cell Types Two categories: 1. Cell that have membrane-bound organelles  Called Eukaryotic Cells 2. Cells that do not have membrane-bound organelles  called prokaryotic cells Unicellular organisms such as bacteria are examples of prokaryotes.

Eukaryotes 1. Has a nucleus with a nuclear envelope 2. Bigger and more complex than prokaryotes 3. Have membrane bound Organelles ( golgi, ER, lysosomes…etc) 4. DNA – double-stranded and forms chromosomes (highly organized) 5. Can be uni- OR multicellular organisms 6. Ex: animals, plants, fungi

Plasma Membrane/Cell Membrane continued: allows nutrients to enter the cell and waste to be removed  This is referred to as selective permeability. *(Selective=Chooses, Permeability=filter through)* keeping a healthy balance of nutrients and water within the cell is called homeostasis

Overview of Organelles Nucleus-  Largest organelle in the cell and it is the most inner compartment of the cell  contains chromatin (DNA); genetic information on strands called chromosomes  “control center” for cell metabolism and reproduction Chromatin- Directions on how to make proteins Nucleolus- Found inside nucleus; ribosomes are made here

Overview Cont’d Ribosomes- make proteins (made up of RNA and protein); thought of as “factories” Cytoplasm- clear gel like fluid inside the cell, which suspends all organelles Endoplasmic Reticulum- extensive network of membranes  Rough ER: with ribosomes  Smooth ER: with no visible ribosomes Golgi Apparatus- sorts proteins made by the ribosomes and sends them to needed places in the cell

Lysosomes- organelles that are filled with digestive enzymes to remove waste and invading bacteria Mitochondria- often referred to as the “powerhouse” of the cell  release energy for the cell  It converts the energy stored in glucose into ATP for the cell Vacuoles- fluid filled organelles enclosed by a membrane  Store materials such as food, sugar, water, and waste products

Eukaryotic plant cell Plant cells are also Eukaryotic cells, but plant cells contain some organelles that are not found in animal cells.

Plant Cell Organelles Cell wall- rigid wall outside the plasma membrane. It provides the cell with extra support. Chloroplasts- captures light and energy; and converts it into chemical energy. Chlorophyll- green pigment found inside the chloroplast. Plastids- organelles that store things such as food in the plant cell.

Prokaryotes 1. NO nucleus 2. NO membrane bound organelles (just ribosomes) 3. ALL are unicellular 4. Smaller than eukaryotic cells 5. Forerunner to eukaryotic cells (smaller and more simple) 6. DNA – single strand and circular 7. Ex: ALL Bacteria

Similarities 1. Contain all four biomolecules (lipids, carbs, proteins, and nucleic acids) 1. Have ribosomes 2. Have DNA 3. Similar Metabolism 4. Can be unicellular 5. Have cell/plasma membranes or cell wall

Bacterial cell Animal cell Plant cell

Eukaryote VS. Prokaryote Picture

Part of CellPart of Factory CapsuleSecurity Gate Cell WallOuter Fence around the factory ChloroplastSolar Panel CytoskeletonMoving Belt where items are inspected Steel Support, Interior Walls Cilia/FlagellaConveyor Belt, Elevator/Escalator EnzymeWorker; Assemblage Machinery Golgi ComplexDistribution/Packaging Department Mailroom MitochondrionGenerator, Engine Room, Power Source NucleoidStorage of pre-production material NucleusSupervisor’s Office, Boss Corporate Office, Central Operations Plasma MembraneLoading/Unloading Dock, Inner Wall, Door RibosomesAssembly Line Track RERProduction Line SERShipping Dock VacuoleStorage Area

Scientists to Remember Robert Hooke (1665) – Observed “cells” in cork

Anton van Leeuwenhoek (1674)  Father of Microscopy  Saw tiny living things in pond water.

Scientists Robert Hooke (1665) – Observed “cells” in cork Anton van Leeuwenhoek (1674) – Saw tiny living things in pond water. Matthias Schleiden (1838) – Plants are made of cells. Theodor Schwann (1839) – Animals are made of cells. Rudolf Virchow (1855) – New cells come from existing cells.

Scientists Janet Plowe (1931) – Cell membrane is a physical structure. Lynn Margulis (1970) – Organelles were once free-living cells.

Microscopes Light Microscope – magnifies tiny organisms up to 1,000 times. -Uses light and lenses. -We use these. Electron Microscope – magnifies up to a million times. -Uses electrons.

Shapes of Prokaryotes Cocci = spherical (round) Cocci = spherical (round) Bacillus = (rod shaped) Bacillus = (rod shaped) Spirilla = helical (spiral) Spirilla = helical (spiral)

Evidence 2- Comparing Fungi and Bacteria Day 1  1. On the bottom of the plate (the side that has the agar): label the plate with your name, period, lab station number (along the edge and as small as possible)  2. Equally divide the bottom of the plate into five equal sections.  3. Take a “sterile” cotton swab and rub on any surface (DO NOT put swab in/on/around any human orifice). Quickly rub the swab on the plate. Write on the bottom of the plate where the swab came from. Dispose of the swab in the special container.  4. When all four sections are done (one section is blank), turn the plate upside down so that the side with the agar is facing up.

Evidence 2- Comparing Fungi and Bacteria Day 2  1. Draw a picture of EXACTLY what you see. Color pencils will be used.  2. Using the microscope what shapes can you identify. (cocci, bacillus, spirilla)  3. Be sure to draw a prokaryotic and eukaryotic cell. Also be sure to draw a fungal and bacterial cell. (Reflection)

Analysis Q’s 1. What type of cell are Fungi and Bacteria? (prokaryotic or eukaryotic) 2. If bacteria is too small to see, why can you see them on the agar plate? 3. What was the purpose of leaving one of the parts of the plate empty? 4. Are fungi cells more closely related to bacteria or animal cells? Why?

Summary In a well developed paragraph:  What did you think before about prokaryotic and eukaryotic cells? (look back at your initial thoughts)  What did you learn about prokaryotic and eukaryotic cells? Be specific! (look back at your evidence section).  What evidence do you have that you learned this?  Further Thoughts Make sure this is thoughtful and thorough.

Reflection Draw a picture of a fungal and bacterial cell. *Be sure to note similarities and differences.

Big Idea Come up with your own Big Idea.