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Cell Structure

Cell Structure. https://www.youtube.com/watch?v=gFuEo2ccTPA&feature=youtu.be. I. Looking at Cells. A. Scientists only became aware of cells after the invention of the microscope. 1. 1665 :Robert Hooke observed cork cells and called them “little boxes”.

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Cell Structure

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  1. Cell Structure https://www.youtube.com/watch?v=gFuEo2ccTPA&feature=youtu.be

  2. I. Looking at Cells • A. Scientists only became aware of cells after the invention of the microscope. • 1. 1665:Robert Hooke observed cork cells and called them “little boxes”. 1675:Anton van Leeuwoenhoek used a microscope and observed pond water. He discovered many living creatures.

  3. B. Measuring Cell Structures • 1. Measurement taken by scientists are expressed in Metric Units. The official name of the metric system is International System of Measurements. • The metric system is based on powers of 10.

  4. fill in the metric chart.

  5. C. Types of Microscopes • 1. Compound Light Microscope The most powerful Light microscopes can magnify up to 2000X. • 2. Electron Microscope Electron microscopes can magnify up to 200,000X. • Transmission Electron Microscopes (TEM)reveal internal details. • Scanning Electron Microscopes (SEM)shows 3-D images of surface.

  6. Eyepiece Body Tube Revolving Nosepiece Objectives Arm Stage Clip Stage Course Adjustment Diaphragm Fine Adjustment Light Base

  7. Eyepiece – lens closest to the viewers eye • Body Tube – directs light from the objective to the eye • Revolving nosepiece – hold the objectives • Arm – holds the base of the microscope with the objectives and eyepiece • Stage Clips – hold the slide in place • Stage – supports the slide

  8. Course Adjustment – used to bring an object into focus under LOW power • Fine Adjustment – used to fine tune the focus under LOW and HIGH power • Base – holds the light source, connects to the arm to hold the other parts of the microscope together • Objective – more magnification of the objective • Light source – light source • Diaphragm – controls the amount of light that travels through the specimen

  9. II. Cell Theory • A. Whose observations helped form the CELL THEORY? • 1838- MattiasSchleiden concluded that cells make up every part of the Plant. • 1839- Theodor Schwann concluded that animals are made up of cells. • 1858- Rudolph Virchow determined that cells only come from other cells.

  10. B. 3 parts of the Cell Theory • 1. All living things are made up of one or more cells. • 2. Cells are the basic units of structure and function in organisms. • 3. All cells arise from existing cells.

  11. CELL SIZE • Small cells function more efficiently than large cells. • How many cells are our bodies made up of? 100 trillion • The advantage of cells being smaller is that substances that enter or leave a cell must cross that cell’s surface; if the cell is small they can exchange substances more readily than large ones.

  12. Relationship between Surface area and Volume

  13. Common Features of Cells • Cell Membrane- outer boundary of cell • Function- regulates what enters and leaves the cell • Made up of- phospholipids and proteins • Cytoplasm- fills the cell;cellparts are suspended in this • Function- same as above • Made up of- water and salts

  14. Cytoskeleton- a system of microscopic fibers • Function- provides framework, shape and support • Made up of- protein fibers

  15. Ribosomes- proteins are made here • DNA- found in the nucleus • Function- provides instructions for making proteins, regulates cell activities • Made up of- nucleotides

  16. 5. Prokaryotes • Smallest and simplest cells. • Prokaryote- is a single-celled organism that LACKS a nucleus and other compartments • They were the only organisms on Earth for 2 billion years. They are very simple and small. The familiar prokaryotes that cause infection and cause food to spoil are commonly called Bacteria.

  17. Characteristics of Prokaryotes • They can live everywhere. • They can cause infection in humans and grow and divide very rapidly. • Some do not need oxygen to survive. • Some can make their own food. • Prokaryotic cells have cytoplasm, cell wall, ribosomes, cell membrane & DNA (circular). Some have flagella for movement. • Some prokaryotic cell walls are surrounded by a capsule that enables the cell to cling to almost anything.

  18. . Flagellum Capsule DNA Plasma Membrane Cell Wall Ribsomes

  19. 6. Eukaryotic Cells • A eukaryote is an organism whose cells have a nucleus. • Organelle-parts of the cell that carry out specific activities • Nucleus-internal compartment that holds DNA Function- controls cells activities

  20. Cilia-short hair-like structures • Function-used for movement • Cytoskeleton- provides interior framework • Function- support and shape of the cell • Made up of- protein fibers: microfilaments, microtubules, intermediate fibers

  21. 6. CellMembrane • Cell Membrane- selective permeability (barrier) • Made up of- phospholipids and proteins • Draw a picture below of the Cell Membrane- Phospholipid and a Lipid bilayer:

  22. 7. Membrane Proteins • Serve many roles including: as markers; as receptors to recognize and bind to substances; as enzymes; as transport proteins to move substances across the membrane

  23. The Nucleus Contains Hereditary information- DNA & RNA RNA- made in nucleus; used to make proteins DNA- wound tightly into chromosomes Humans have 46 chromosomes. Garden peas have 14 chromosomes. III. Cell Organelles

  24. B. Endoplasmic Reticulum-system of internal membranes • Function- moves proteins and other substances through the cell • Made up of- lipid bilayer & embedded proteins • Rough ER- contains ribosomes • Smooth ER- (lacks ribosomes)-makes lipids and breaks down toxins

  25. C. Golgi Apparatus- flattened membrane- bound sac • Function- package and distribution center (UPS) • Made up of- proteins • D. Lysosomes- vesicles that bud off of Golgi Apparatus • Function-contains cell digestive enzymes

  26. E. Mitochondria- “MIGHTY MITOCHONDRIA”-site of cell metabolism (more mitochondria=more energy) • Function-makes energy ATP for the cell • Made up of- 2 membranes-inner is folded out and outside is smooth.

  27. F. Structures of Plant Cells--------3 structures found only in PLANT CELLS. • 1. Cell Wall- surrounds the cell membrane • Function- support & maintains shape of the cell • Made up of- proteins, carbohydrates->cellulose • 2. Chloroplasts- found in plant cells as well as algae • Function-use light energy to make Carbohydrates ->glucose (sugar) • Made up of- 2 membranes; has own DNA • 3. Central vacuole- takes up most of a plant cell’s volume • Function-stores water ,nutrients, wastes (when full cell wall is rigid)

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