BIOTECHNOLOGY Chapter 4 Cells: The Foundation of Life Troy Area High School Mr. Schanbacher

Essential Questions Why are cells the foundation of life? What are the different types of cells? What are the differences between prokaryotic and eukaryotic cells? What are the different components of cells? How do cells reproduce by mitosis? What is the process of meiosis? What are stem cells?

The Importance of Cells! The most basic life processes take place at the cellular level: Reproduction Growth Immunity Nutrient Utilization Almost all modern BT is based on the functions and interactions of plant and animal cells.

Electron Microscope Invented in the 1940’s Has allowed us to understand cellular funtions

What are the different types of cells? Cells come in all shapes and sizes

Prokaryotic VS Eukaryotic.

Prokaryotic Cells Contain genetic material but it is not confined to the nucleus. DNA is contained within a single molecule and is in contact with the cytoplasm. Smallest of all cells and generally considered neither plant nor animal. Bacteria and Archaea

What is the importance of prokaryotic cells in biotechnology? Wine, cheese, yogurt, etc. Genetically engineered bacteria produce certain proteins: Insulin Hepatitis B vaccine Tissue plasminogen activator Human growth hormone Ice-minus bacteria Interferon bt corn rBST

Eukaryotic Cells Plants and Animals Larger than PC’s Have a (or more than one) nucleus made mostly of nucleic acid (Capital Building) Contains DNA DNA contains all genetic info responsible for giving an organism its characteristics (we will look at this more in depth next chapter) Surrounding the nucleus is a clear fluid called cytoplasm Contain all the material needed to conduct life processes. Contains membrane-enclosed structures called organelles Organelles perform specialized structures within the cell. Both the nucleus and cytoplasm are contained within a cell membrane and are made of proteins and lipids.

What are the components of eukaryotic cells? Cell Membrane Cell Walls Organelles Mitochondria Vacuoles Microtubules Microfilaments Ribosomes Golgi apparatus Endoplasmatic reticulum Lysosomes Plastids Chloroplasts Leucoplasts Chromoplasts

What is the purpose of the cell membrane? Cell membrane=Plasma membrane (Gate) Phospholipid bilayer Three Purposes 1. Encloses and protects the cell’s contents from external environment 2. Regulates the movement of materials into and out of the cell (nutrients and waste) 3. Allows for interaction between other cells Plants: Cell Wall Animals: Plasma Membrane

Diffusion (video)(video) The cell membrane is selective or semipermeable Only certain substances can pass Small or charged molecules and ions (charged molecules) Water and other nutrients in….Waste Out This process is called diffusion (Passive Transport) Molecules in solution pass through the membrane from a region of higher concentration of molecules to an area of lower concentration Example: Animal cells have fewer molecules of oxygen inside the cell than outside and have more carbon dioxide molecules inside than out….diffusion is needed to take in oxygen and release CO2!

Osmosis The movement of water in and out of the cell

Egg Experiment Materials Needed: 2 eggs per group 2 Containers Vinegar Scale Tap Water Food Coloring Corn Syrup Directions and Worksheet

Homeostasis The ability of an organism to remain stable when conditions around it are changing. When cells are filled with water they build up internal pressure that is called turgor. Turgor keeps the cells membranes taut. What are some examples of cells lacking turgor pressure?

Cell Walls ONLY FOUND IN PLANTS!!! Cell Walls give the plant cell its shape and provides protection for the plant Made of cellulose We utilize cellulose found in hard plant cells (lumber, paper, cotton, etc.) Pectin Found in softer plant tissues such as leaves and fruit Used to make jelly to give it a thick consistency Plant Cells are held together by contact of individual cell walls.

Cell Wall

Organelles Within the cytoplasm of cells are small structures that serve different roles. Mitochondria Vacuoles Microtubules Microfilaments Ribosomes Golgi apparatus Endoplasmatic reticulum Lysosomes Plastids Chloroplasts Leucoplasts Chromoplasts

Mitochondria Peanut Shaped Functions to break down food nutrients and supply the cell with energy (ATP=currency of cell). The more energy a cell needs (muscle cells) the more mitochondria they contain. The POWER HOUSE of the cell

Vacuoles Plant cells usually have one large vacuole and animal cells have many smaller ones. Serve as storage compartments for the cell Store water, nutrients and waste Vacuole

Microtubules Contained in some animal cells Thin hollow tubes that act as the “bones” for the cell. Supports the cell and gives the cell its shape.

Microfilaments Fine fiberlike structures composed of proteins that help the cell move by waving back and forth.

Ribosomes Site where protein molecules are assembled in the cell. Act as FACTORIES which translate DNA from the nucleus to useable proteins molecules. Proteins are needed by all cells for growth and other important functions.

Golgi Apparatus Shaped like a bunch of flat sacks Function to remove water from proteins and prepare them (package) for export from the cell. THE POST OFFICE.

Endoplasmic Reticulum Interconnected tubules and vesicles to transport proteins throughout the cell. THE HIGHWAY

Lysosome Digestive unit of cell Break down Proteins Carbs Bacteria Other foreign material that enters cell Worn out and nonfunctional cell parts TRASH MAN

Plastids Found only in plant cells 1. Chloroplasts 2. Leucoplasts 3. Chromoplasts

Chloroplasts Use energy from the sun to make carbs. Contain chlorophyll

Cell Reproduction Meiosis and Mitosis!

What is Meiosis? Cells are divided into cells that contain only one-half of chromosomes needed for the formation of the young animals. (Humans n=23) This is a haploid cell These cells are called sex cells or gametes (sperm and egg) The process is spermatogenesis in male and oogenesis in females Figure 4-15 When the two gametes combine all the chromosomes needed are there (Humans n=46) This is a diploid cell.

What is Mitosis? All growth that takes place in living organisms comes about as a result of cells increasing in size or number. The process by which cells multiply is MITOSIS!!!! When a cell grows it reaches a maximum size and then it divides into two cells. The original cell is the parent cell and the new cells are called the daughter cells.

Phases of Mitosis Interphase Prophase Metaphase Anaphase Telephase

Interphase The period when the cell is not actually dividing G1=Growth One=Cellular contents except chromosomes are duplicated S=DNA or Chromosome replication G2=Growth Two=Cell double checks its chromosomes and grows to its maximum size…cell is now ready to divide!

Prophase First True Phase of Mitosis Chromatin appears in the form of shortened rodlike structures Chromosomes are formed of two strands called chromatids that are attached at the center by a structure called the cetromere (kinetichore) Nucleus dissolves Spindle forms in place of nucleus and centrioles move to opposite sides of the cell

Metaphase Chromatids move toward the center (equator) of the spindle When they reach the center, the center of the centromere of chromatids connect themselves to the fibers of the spindle

Anaphase Chromatids separate into an equal number of chromosomes Centromeres duplicate When separation occurs, the chromosomes move to opposite ends of the cell

Telophase The chromosomes continue to migrate to the opposite ends of the cell (called poles) The spindle disappears and new membranes are formed around the chromosomes This forms two new nuclei This completes MITOSIS (but wait there is more!!!)

Cytokinesis This step completes cell division Division of the cytoplasm Animal Cells Cleavage furrow deepens until the cell membrane divides along with the cytoplasm Plant Cells Cell plate forms in the middle of the spindle and grows outward until the cell is split

Daughter Cells (watch again)(watch again) The newly created cells are called daughter cells They are genetically identical to each other and the parent cell that formed them

Animal Stem Cells These cells are essentially cells that can become anything (muscle, brain, blood, heart, etc.) They are undifferentiated or unspecialized They are extremely important and controversial READ MORE

Essential Questions Why are cells the foundation of life? What are the different types of cells? What are the differences between prokaryotic and eukaryotic cells? What are the different components of cells? How do cells reproduce by mitosis? What is the process of meiosis? What are stem cells?