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Inner life of a cell http://www.aimediaserver.com/stu
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Section 3-2 (pages 55-60)
Cell FeaturesObjectives:1. List the three parts of the cell theory. (pg.
55)2. Determine why cells must be relatively
small. (pg 55)3. Compare the structure of prokaryotic
cells with that of eukaryotic cells. (pg. 57)
4. Describe the structure of cell membranes. (p. 59)
Key TermsCell Theory
Cell MembraneCytoplasmRibosomeProkaryoteCell WallFlagellumEukaryoteNucleus
OrganelleCillium
PhospholipidLipid Bilayer
What are the three parts of the Cell theory
1. All living things are made up of cells.
2. Cells are the basic units of structure and function in organisms.
3. All cells arise from existing cells.
Antony van Leeuwenhoek (1632-1723)
Why Must Cells be Small?
If the cell’s surface area-to-volume ratio is too low, substances cannot enter and leave the cell in numbers large enough to meet the cell’s needs.
substances do not need to travel as far to reach the center of a small cell
What Features are Common of cells?
Cell membrane
Cytoplasm
Cytoskeleton
Ribosomes
What is the Cell Membrane (plasma membrane)
Cell Membrane: is the outer boundary layer of the cell, made up of phospholipids. It regulates what enters and leaves a cell – including, gases, nutrients, and wastes.
What are phospholipids• A phospholipid is a lipid made up of a
phosphate group and two fatty acids.• It has a hydrophilic head (water
loving) and a hydrophobic tail (water hating)
What is the lipid bilayer• In a cell membrane, the
phospholipids are arranged in a double layer called a lipid bilayer.
• The nonpolar (water hating) tails make up the interior of the bilayer, and the polar (water loving) heads make up the outer layer.
Cytoplasm
Cytoplasm: The interior of the cell which houses many organelles and cellular structures.
Cytoskeleton
A system of microscopic fibers (tubules), inside the cytoplasm, that many organelles are suspended from.
Ribosome
Ribosome: Cellular structures on which proteins are made.
What is a Prokaryote (Bacteria)
• Prokaryotes are the smallest and simplest cells
• They are singled celled organisms that lack a nucleus, cytoskeleton, and other internal compartments.
What are the Characteristics of Prokaryotes (Bacteria)
• Bacterium’s enzymes and ribosomes are free to move around in the cytoplasm because they lack internal compartments.
• Bacteria have a cell wall providing structure and support
• Some bacteria have a flagella, long threadlike structures that enable movement.
What are Eukaryotes
• Eukaryotes are organisms whose cells have a nucleus, other internal compartments, and organelles.
What are Organelles
• An organelle is a structure that carries out a specific function in the cells.
What organelles are found only in Eukaryotes
NucleusMitochondriaChloroplastsCytoskeleton
VacuoleGolgi bodies
Lysosomes (vesicles) Smooth endoplasmic reticulumRough endoplasmic reticulum
The Eukaryotic Nucleus
The nucleus is a membrane bound internal compartment that houses the DNA
What is the Form and Functionof the
DNA moleculeForm: A double helix (looks like a
twisted extension ladder)
Function: Stores the hereditary information that controls all cell processes.
What is the Form and Functionof the
Mitochondria?
Form: A kidney shaped organelle floating around in the cytoplasm, with a set of internal folding membranes.
Function: It converts the energy stored in food compounds into a useful form, called ATP (adenosine triphosphate)
Form and Function of the Endoplasmic Reticulum (ER)
Form: A network of lipid bilayer membranes.
Function: Moves proteins and other substances through the cell
What does the Rough ER do?
Contains ribosomes on its surface and makes proteins. It also makes new membranes
What does the Smooth Endoplamsic Reticulum do?
Makes lipids, Also processes carbohydrates and modifies toxic chemicals in the cell
What is the Form and Functionof the
Golgi Apparatus?Form: Flat pancake like sacs
Function: It’s the post office the cell. It makes vesicles, such as lysosomes; that store, sort, changes, packages, and distributes proteins throughout the cell.
What is the Form and Functionof Lysosomes?
Form: Made by the Golgi Apparatus. Small spheres floating around the cytoplasm that contain digestive enzymes
Function: Lysosomes break down bacteria viruses, and non functional organelles within the cell.
Often nicknamed “suicide bags”
VacuolesCell Walls
Chloroplasts
What is the Form and Function ofVacuoles?
Form: Sacs that are often found in plants cells
Function: They absorb water, store proteins, ions and waste products.
What is the form and function of Cell walls?
Form: A tough ridged outer covering that surrounds the cell membrane of plants and bacteria cells.
Function: It protects the plant cell and give it shape.
What is the Form and Functionof
Chloroplasts?Form: Green oval-shaped structures
Function: enable plants to make sugars through photosynthesis
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