Today’s Plan…. 18 Feb 2013  Introduction to the “Cell”  Cell as a Factory Notes  Textbook Exploration  Scan pages in book  Label Cell Diagrams  Cell Vocabulary  Tomorrow’s Plan  Build your own Cell…

The Cell: A Factory Comparison Unit 1 Cells & Systems: Section 1.2 Cells

The Cell: A Quick intro…  CELL THEORY  The cell is the basic unit of life.  Cells are the fundamental units of life.  All living things are made of cells.  There are two types of Cells:  Prokaryotes: bacteria  Eukaryotes: plants & animals  But before we get to far, A Video for your enjoyment… google&hl=en&v=RU5Ymc00S4w&nomobile=1 google&hl=en&v=RU5Ymc00S4w&nomobile=1 IMPORTANT!!! (Add to notes!)

The Cell as a Factory  Imagine a bustling factory manufacturing the latest must- have gadget. Whether they make bicycles, cell phones, or hot air balloons, most factories are set up in essentially the same way.  All factories have exterior walls that protect and support them and interior walls that create separate work areas.  They usually have some kind of production line where a product is assembled and an executive department that decides what product is made. A finishing department processes and prepares the product for shipping, and a packaging department wraps the product.

Cell as a Factory.2  In addition, a factory has a receiving department that brings in the components it needs to make its product, a communications department that allows it to contact suppliers, and a power plant that provides the energy it needs to run. Finally, a custodial staff keeps everything clean and in good working order.  Cells are very similar to factories. To stay alive and function properly, cells have a division of labor similar to that found in factories. Here, we will examine cells as protein-producing factories.

Eukaryotic Cells: Animal & Plant Cells  All eukaryotic cells are composed of a plasma membrane, a nucleus, and cytoplasm.  There are differences between Animal & Plant cells…  Plant Cell – has a tough rigid cell wall, this supports not only the cell, but provides support for the growing plant, more on these differences later…

The Plasma Membrane  The PLASMA MEMBRANE regulates what enters or leaves the cell. It is similar to the shipping and receiving department of a factory.  The plasma membrane also functions as the communications department because it is where the cell contacts the external environment.

The Nucleus  The NUCLEUS (or the executive department, aka CEO) runs the cell factory and controls all cell activity. It determines what proteins are to be made and stores all the plans for any proteins that the cell currently makes or has made in the past.

The Nuclear Membrane  The nucleus is composed of a nuclear membrane and nucleoplasm.  When the factory gets too large, it is difficult to run properly; thus, another factory must be built. To prepare for this, you have to provide the new factory with its own set of all the blueprints.  The nuclear membrane contains the blueprints of the cell. The information for the manufacture of proteins is encoded in a series of bases along the DNA found in the nucleus.

The Cytoplasm  It contains various kinds of cell structures and is the site of most cell activity. The cytoplasm is similar to the factory floor where most of the products are assembled, finished, and shipped.  It is the gelatin-like material that is found within the plasma membrane.

The Cytoplasm  The real work of the cell occurs in the cytoplasm.  “Cytoplasm" refers to structures between the cell membrane and the nuclear membrane.  These structures perform several different functions for the cell which generally fall under the categories of production, maintenance, and energy transformation.

Endoplasmic Reticulum  The ER is the part of the cell where the “factory workers” do their work – it is the assembly line.  A collection of large, flattened membranes that folds back and forth on each other. Divided into “smooth and rough ER”  Stretches from the nuclear membrane to the plasma membrane.

Ribosomes  These are the “workers” of the assembly line. The Ribosomes are located on the Rough ER.  The ribosomes build the proteins that are manufactured by the nucleolus.

Golgi Apparatus  Once the proteins are manufactured, they move to the Golgi Apparatus, known as the finishing & packaging department.  These proteins are packaged into membrane shaped structures called vesicles.  The vesicles carry proteins, nutrients, and water in, out, and around the cell.

Lysosomes  The “maintenance crew”  LYSOSOMES are organelles produced by the Golgi apparatus that contain powerful protein digesting enzymes.  Are responsible for the breakdown and absorption of materials taken in by the cell.  Contain digestive chemicals that break down food particles, cell wastes, and worn-out cell parts.  i.e. When a white blood cell engulfs a bacterium, it is the lysosomes that digest the bacteria.

Cytoskeleton  The CYTOSKELETON maintains the cell's shape and can be used to move the cell membrane.  Within the cytoplasm of the cell are many protein fibers that act as support structures. These protein fibers, called MICROFIBERS are composed of a specialized protein called ACTIN.  Actin has the ability to link together to form fibers quickly. These fibers make up an invisible support structure inside the cytoplasm called the cytoskeleton.

Mitochondria/Chloroplasts  Building proteins is the main function of cells. But for this to occur, a cell must have an energy source, and that energy must be in a form that the cell can use.  The mitochondrion and the chloroplast are the two organelles responsible for energy transformation.  Chloroplasts don't exist in animal cells; they are present in plants.  Mitochondria exist in both Animal and Plant cells.

Animal vs Plant Cell What makes them different…

Animal Cell  Mitochondria, through cellular respiration, produce energy for the cell.  CR takes the chemical energy we take in through food, and changes it into energy needed for cell function.  Referred to as our metabolism

Plant Cell  Through photosynthesis, chloroplasts & mitochondria create energy for the plant cell:  Chloroplasts trap light energy and convert it into the chemical bond energy of sugar.  Mitochondria take the energy that is trapped in the form of sugar and convert into a form that the cell can easily use. Photosynthesis: chemical reaction when Carbon Dioxide & Water react in presence of sunlight to produce glucose (sugar) and oxygen.