1. Cell Structure

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”. and called them “little boxes”. 1675:Anton van Leeuwoenhoek used a 1675:Anton van Leeuwoenhoek used a microscope and observed pond water. He microscope and observed pond water. He discovered many living creatures. discovered many living creatures.

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

5. fill in the metric chart. fill in the metric chart.

6. 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.

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

8. EEEEyepiece – lens closest to the viewers eye BBBBody Tube – directs light from the objective to the eye RRRRevolving nosepiece – hold the objectives AAAArm – holds the base of the microscope with the objectives and eyepiece SSSStage Clips – hold the slide in place SSSStage – supports the slide

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

10. *******TAKS QUESTION******  The English scientist Robert Hooke used a crude microscope to examine  A. individual atomsC. single-celled organisms  B. electronsD. cork cells

11. II. Cell Theory  A. Whose observations helped form the CELL THEORY?  1838- Mattias Schleiden 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.

12. 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.

13. 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. 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.

14. Relationship between Surface area and Volume Relationship between Surface area and Volume

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

17. CCCCytoskeleton- a system of microscopic fibers FFFFunction- provides framework, shape and support MMMMade up of- protein fibers

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

19. 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.

20. Characteristics of Prokaryotes  They can live everywhere.  They can cause infection in humans and grow and divide very rapidly.  Some do not need oxygen 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.

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22. 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 Function- controls cells activities

23.  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

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

26. 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  ***************TAKS Question: ****************  A bacterium that lost its flagella would be unable to  A. divideC. maintain its shape  B. moveD. make proteins

27. III. Cell Organelles  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.

29. 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

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

31. 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) 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)

33. ******** TAKS Question****** ******** TAKS Question******  Which organelle serves as the packaging and distribution center of a eukaryotic cell? A. NucleusC. Mitochondrion B. LysosomeD. Golgi Apparatus A. NucleusC. Mitochondrion B. LysosomeD. Golgi Apparatus