Today’s Discussion: 1)Eukaryotes vs. Prokaryotes 2)Plant vs. Animal

Size of Living Things 1 m = 100 cm = 1,000mm = 1,000,000 µm = 1,000,000,000nm 1mm = 1000 µm = 1000000nm 1 µm = 1000nm Diagrams: LargeDiagram : http://www.cellsalive.com/howbig.htm RelativeScale : Created by TimVickers, vectorized by Fvasconcellos

Two basic types of cells Prokaryotes -Almost always single-celled -Reproduce by binary fission (we’ll cover this term in February). -No cell nucleus or any other membrane-bound organelles i.e. DNA travels openly around the cell. All bacteria are prokaryotes. Eukaryotes -Can either be single-celled or multi-celled. -Can reproduce in one of several ways (Ex. meiosis, mitosis). -Have cell nucleus within containing its DNA.

Prokaryotic Cells: The details Pro-, “before”, karyon, “nucleus” Believed to be the first cells to evolve. Lack a membrane bound nucleus and organelles. Genetic material is naked in the cytoplasm Ribosomes are only organelle. Image: Mariana Ruiz

Eukaryotic Cells (eu-, “true”, karyon, “nucleus”) Genetic material contained in a nuclear membrane. Membrane bound organelles. Evolved from prokaryotic ancestor. Image: Mariana Ruiz

Comparison of Eukaryotic and Prokaryotic Cells Image: k12station.blogspot.com/2006_08_01_archive.html

Animal Cell

Plant Cell Figure 7-5 Plant and Animal Cells Section 7-2 Go to Section:

ANIMAL CELLS

Cytoplasm Function: a molecular matrix in which the organelles are suspended Consists of cytosol and organelles, except for the cell nucleus. Cytosol is made up of water, salts, organic molecules and many enzymes that catalyze reactions.

Cytoskeleton Functions: Multiple Maintains cell SHAPE Protects the cell Enables some cell MOVEMENT (using structures such as flagella and cilia) Plays important roles in intra-cellular transport (the movement of vesicles and organelles) Plays important role in cellular DIVISION

Centrioles & Centrosomes The Centriole, also called the "microtubule organizing center", is an area in the cell where microtubules are produced. Function: Area in which Microtubules are produced. Within the cells of animals are a pair of Centrosomes, made of nine sets of triplet microtubules. Function: Allows the cell to split during Mitosis

Cilia & Flagella Functions: • External appendages from cell membrane • Aid in locomotion of the cell. • Internal structure consists of microtubules. • Motility > coordinated sliding movements of microtubules.

Organelles: Ribosome Function: Make proteins Can be found alone in the cytoplasm, in groups called polyribosomes, or attached to the endoplasmic reticulum.

A SIDE NOTE…. Mitochondria & Chloroplast Found in plants & animals Mitochondria & Chloroplast Both organelles house energy in the form of ATP. Both ancestrally were independent cells that formed a symbiotic relationship with other cells (what is this theory called?) Not found in animals

Mitochondria Function: Energy formation. Breaks down glucose to make ATP Bound by a double membrane surrounding fluid-filled matrix.

Chloroplasts Bound by two membranes enclosing a fluid-filled stroma that contains enzymes. Function: Absorb solar energy and produce carbohydrates

Nucleus Function: Separates the genetic material (DNA) from the rest of the cell. DNA, the genetic material, is a blueprint, or code for making proteins.

Endoplasmic Reticulum Function: Internal production & delivery system of the cell. Rough ER is studded with ribosomes. Site of protein synthesis and processing. Smooth ER lacks ribosomes. Site of synthesis of phospholipids and packaging of proteins into vesicles. Endoplasmic Reticulum Saccules are flattened vesicles.

Golgi Apparatus Functions: -Receives protein and also lipid-filled vesicles from the ER, packages, processes, and distributes them within the cell or for export out of the cell (secretion). -encloses digestive enzymes into membranes to form lysosomes.

Function: Store, transport, or digest cellular products and waste. Small compartments separated from the cytosol by at least one lipid bilayer. Made in Golgi apparatus, ER, or from parts of the plasma membrane. Vesicles form while taking in (Endocytosis) or discharging (Exocytosis) materials. Vesicles

Lysosomes Function: Break down food into particles the rest of the cell can use and to destroy old cells -Contain hydrolytic enzymes and are involved in intracellular digestion.

Now we will discuss the organelles specific to plant cells We have now talked about the structure and function of animal cells. Now we will discuss the organelles specific to plant cells

Chloroplasts Bound by two membranes enclosing a fluid-filled stroma that contains enzymes. Function: Absorb solar energy and produce carbohydrates

Vacuole Figure 7-5 Plant and Animal Cells Function: Stores water Section 7-2 Please water me! - This is what makes lettuce crisp. - When there is no water, the plant wilts. Go to Section:

Cell Wall Function: Provides support and protection to the cell membrane Found outside the cell membrane in plant cells

What is the difference between these two?? http://www.cellsalive.com/cells/cell_model.htm