Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 4.  Cell: the smallest unit that can carry on all of the processes of life.

Similar presentations


Presentation on theme: "Chapter 4.  Cell: the smallest unit that can carry on all of the processes of life."— Presentation transcript:

1 Chapter 4

2  Cell: the smallest unit that can carry on all of the processes of life.

3  Studied nature  Used “light microscope” pg 69  Viewed a thin slice of cork  Saw many little boxesCELLS

4  First to observe living cells  Microscope lens was 10x that of Hooke  Was first able to see unseen world of microorganisms  First to view a REAL cell

5 Botanist First to view plant cells Concluded: All plants are composed of cells.

6  Zoologist  Concluded: All animals were made of cells.

7  Physician  All cells come from other cells.

8  1. All living organisms are composed of one or more cells.  2. Cells are the basic units of structure and function in an organism.  3. Cells come only from the reproduction of existing cells.

9  Discovery of cells and cell theory:   MICROSCOPE

10  1. made of organized parts  2. obtain energy from their surroundings  3. perform chemical reactions  4. change with time  5. respond to the environment  6. reproduce

11  In a body: pg 72  Different cells  Different shapes  Different functions  All in same body

12  Shape reflects the different functions  PAGE 72

13  A few types of cells are large enough to be seen without a microscope  Ex. Giraffe’s nerve cells: 6 ½ ft long  Human egg cell: size of a period MOST cells: 1/500 th the size of a period

14  SURFACE AREA-TO-VOLUME RATIO  Nutrients and oxygen go in  Waste goes out BOTH pass through surface Happens QUICKLY therefore need more surface area to volume page 73 Cells MUST be microscopic!!!

15 3 basic parts to all cells 1. Cell Membrane 2. Cytoplasm 3. Nucleus

16  Also called the plasma membrane  Covers the surface  Acts as a barrier  All materials enter or exit through this

17  Hold all of the organelles

18  Control center  Holds DNA  Membrane bound and free floating DNA

19 PROKARYOTES  Lack a membrane-bound nucleus  Lack membrane-bound organelles  May have a nucleoid: concentrated area of DNA  DOMAIN Archaea  DOMAIN Bacteria EUKARYOTES  In organisms made up of one or more cells  Contain organelles  Larger in size than prokaryotes

20  Page 76  CellTissueOrganOrgan System

21  Functions:  A. Allows only certain molecules to enter or leave the cell  B. Separates reactions inside the cell from outside the cell  C. Excretes waste  D. Interacts with environment

22  Phospholipids

23  Proteins  Cell surface markers – emerge from only one side of the membrane  Receptor proteins – recognizes and binds to substances outside the cell  Transfer proteins – helps substances move across the membrane

24  Enzyme –

25  Houses and protects genetic information  Chromosomes: holds DNA  Nuclear Envelope: surrounds nucleus Nucleolus: denser area in nucleus

26  Holds organelles

27  Mitochondria  Ribosomes  Endoplasmic reticulum  Golgi aparatus  Vesicles  Microtubules  Microfilaments  centrioles

28  Mitochondria: tiny organelles that transfer energy into ATP  ATP: Adenosine triphosphate  Powers the cell’s chemical reactions  HIGH in # in muscle cells!  FEW in # in fat cells.

29  Small, roughly spherical organelles  Responsible for building protein  No membrane  Made of protein and RNA  Created in nucleus, finished in cytoplasm  Found in  Cytoplasm  Some endoplasmic reticulum

30  Called ER  System of tubes and sacs (cisternae)  Function as a “highway”: a path along which molecules move from one part of the cell to another  2 types:  Rough  Smooth

31  System of interconnected, flattened sacs covered with RIBOSOMES  Pg 81  Produces phospholipids and proteins  Ribosomes on ER:  Produce digestive enzymes that contain proteins  Vesicles (sacs) pinch off and store these enzymes until they are released

32  Smooth appearance  Builds  In ovaries and testes: produces hormones *abundant in liver and kidneys:

33  Long term alcohol and drug abuse:

34  Pg 82  Another system of flattened, membrane sacs  Sacs closest to the nucleus receive vesicles from the ER containing newly made proteins or lipids  Proteins get “address labels”

35  VESICLE: small sacs that head to the plasma membrane and release contents outside of cell  1. LYSOSOME  2. PEROXISOME  3. others

36  Vesicles from Golgi Apparatus that contain digestive enzymes  Breakdown proteins, carbs, fats, bacteria.  Responsible for breaking down cell when it is time to die!

37  Abundant in liver and kidney  Detoxify alcohol and other drugs  Also breakdown fatty acids

38 1. proteins assembled by ribosomes on rough ER 2. Vesicles transport proteins to the golgi apparatus 3. Golgi modifies the proteins and packages them in new vesicles 4. Vesicles release proteins that have destination outside of cell 5. Vesicles needing to remain inside of cell stay.

39  Network of thin tubes and filaments  Give shape to the cell from the inside ex. Tent poles Also acts as a system of internal tracks to allow items to move around in cell Microtubules, Microfilaments, & Intermediate filaments

40  Hollow tubes made of protein called “tubulin” 1. Hold organelles in place 2. Maintain cell’s shape 3. Act as track to guide organelles

41  Finer than microtubules  2 strands of intertwined protein  1. contribute to cell movement  2. muscle contraction  3. maintainance and changing of shape

42  Rods that anchor the nucleus and other organelles to their place  Maintain INTERNAL shape of nucleus

43 CILIA  Extend from surface of cell  Short  Large #’s  Inner ear: vibrate and help detect sounds  Protisits: sweep food into mouthlike opening FLAGELLA Extend from surface of cell Long less #’s

44  Plant cells have 3 additional kinds of structures 1. cell wall 2. large central vacuole 3. plastids

45  Make their own food: photosynthesis  Must reach up towards the sun  Need to hold water

46  Rigid layer outside of plasma membrane Made of cellulose: a carb that makes the cell like a stiff box  2 layers:  Primary wall  Secondary wall (wood)

47  Large, fluid-filled organelle  Mainly stores water  90% of the plants volume  Causes plant to stand upright

48  Used in photosynthesis  Use light energy  Contain chlorophyll: green pigment that absorbs light and captures the light energy

49  Colored pigment  Found in carrots: orange flowers: red, purple, yellow & white


Download ppt "Chapter 4.  Cell: the smallest unit that can carry on all of the processes of life."

Similar presentations


Ads by Google