First to View Cells. copyright cmassengale

Transcription

1 CELL THEORY All living things are made of cells Cells are the basic unit of structure and function in an organism (basic unit of life) Cells come from the reproduction of existing cells (cell division) 1

2 First to View Cells In 1665, Robert Hooke used a microscope to examine a thin slice of cork (dead plant cell walls) What he saw looked like small boxes copyright cmassengale 2

3 First to View Cells Hooke is responsible for naming cells Hooke called them CELLS because they looked like the small rooms that monks lived in called Cells copyright cmassengale 3

4 Prokaryotes Cells that DO NOT HAVE a nucleus and membranebound organelles Nucleoid region (center) contains the DNA Surrounded by cell membrane & cell wall Contain ribosomes (no membrane) in their cytoplasm to make proteins 4

5 Eukaryotes Cells that HAVE a nucleus and membrane-bound organelles Includes protists, fungi, plants, and animals More complex type of cells 5

6 Eukaryotic Cell Contain 3 basic cell structures: Nucleus Cell Membrane Cytoplasm with organelles 6

7 Two Main Types of Eukaryotic Cells Plant Cell Animal Cell 7

8 Organelles Very small (Microscopic) Perform various functions for a cell Found in the cytoplasm May or may not be membranebound 8

9 Animal Cell Organelles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Ribosome (attached) Ribosome (free) Cell Membrane Mitochondrion Smooth endoplasmic reticulum Golgi apparatus Centrioles 9

10 Cell or Plasma Membrane Composed of double layer of phospholipids and proteins Surrounds outside of ALL cells Controls what enters or leaves the cell 10

11 Phospholipids Heads contain choline & phosphate and are hydrophilic (attract water) Tails are made of fatty acids and are hydrophobic (repel water) Make up a bilayer where tails point inward toward each other 11

12 Cell Membrane in Plants Lies immediately against the cell wall in plant cells Pushes out against the cell wall to maintain cell shape Cell membrane 12

13 Cell Wall Cell wall Nonliving layer Found in plants, fungi, & bacteria Made of cellulose in plants 13

14 Cell Wall Supports and protects cell 14

15 15 What is the function of the cell membrane? A) Controls what enters and exits the cell B) Helps determine shape C) Is protective D) A and B

16 16 What is the function of the cell wall? A) Determines cell type B) Supports and protects C) Controls what goes in and out of the cell D) It has none

17 Cytoplasm of a Cell cytoplasm Jelly-like substance enclosed by cell membrane Provides a medium for chemical reactions to take place 17

18 More on Cytoplasm cytoplasm Contains organelles to carry out specific jobs Found in ALL cells 18

19 The Control Organelle - Nucleus Controls the normal activities of the cell Contains the DNA in chromosomes Bounded by a nuclear envelope (membrane) with pores Usually the largest organelle 19

20 Nuclear Envelope Double membrane surrounding nucleus Also called nuclear membrane Contains nuclear pores for materials to enter & leave nucleus Nuclear pores 20

21 Nucleolus Inside nucleus Cell may have 1 to 3 nucleoli Makes ribosomes that make proteins 21

22 22 Which of the following makes Ribosomes? A) Nuclear Pore B) Nuclear Envelope C) Nucleolus D) None of the Above

23 23 Which is NOT true of the cytoplasm? A) Contains all organelles B) is made of a jelly-like substance C) provides a medium for chemical reactions D) is not found in all cells

24 Cytoskeleton Helps cell maintain cell shape Also help move organelles around Made of proteins Microfilaments are threadlike Microtubules are tubelike 24

25 Cytoskeleton MICROTUBULES MICROFILAMENTS 25

26 Mitochondrion (plural = mitochondria) Powerhouse of the cell Generate cellular energy (ATP) More active cells like muscle cells have MORE mitochondria Both plants & animal cells have mitochondria Site of CELLULAR RESPIRATION 26

27 Cell Powerhouse Mitochondrion ( mitochondria ) Rod shape 27

28 MITOCHONDRIA Surrounded by a DOUBLE membrane Has its own DNA Folded inner membrane (increases surface area for more chemical Reactions) Interior called MATRIX 28

29 Interesting Fact --- Mitochondria Come from cytoplasm in the EGG cell during fertilization Therefore You inherit your mitochondria from your mother! 29

30 Endoplasmic Reticulum - ER Network of hollow membrane tubules Connects to nuclear envelope & cell membrane Functions in Synthesis of cell products & Transport Two kinds of ER ---ROUGH & SMOOTH 30

31 Rough Endoplasmic Reticulum (Rough ER) Has ribosomes on its surface Makes membrane proteins and proteins for EXPORT out of cell 31

32 Rough Endoplasmic Reticulum (Rough ER) Proteins are made by ribosomes on ER surface They are then threaded into the interior of the Rough ER to be modified and transported 32

33 Smooth Endoplasmic Reticulum Smooth ER lacks ribosomes on its surface Is attached to the ends of rough ER Makes cell products that are USED INSIDE the cell 33

34 Functions of the Smooth ER Makes membrane lipids (steroids) Regulates calcium (muscle cells) Destroys toxic substances (Liver) 34

35 The role of which organelle is to maintain cell shape and move other organelles around the cell? A) Mitochondria B) Smooth ER C) Centrioles D) Cytoskeleton

36 The role of which organelle is to generate cellular energy? A) Mitochondrion B) Smooth ER C) Centrioles D) Cytoskeleton

37 There are two types of this organelle both of which are made up of hollow membrane tubes and are involved in the synthesis and transport of cell products. A) Cytoskeleton B) Endoplasmic Reticulum C) Mitochondrion D) Plasma membrane

38 Ribosomes Made of PROTEINS and rrna (ribosomal RNA) Protein factories for cell Join amino acids to make proteins Process called protein synthesis à 38

39 Ribosomes Can be attached to Rough ER OR Be free (unattached) in the cytoplasm 39

40 Golgi Bodies Stacks of flattened sacs (looks like stack of pancakes) Have a receiving side (cis face) and a shipping side (trans face) Receive proteins made by ER The Transport vesicles with modified proteins pinch off the ends CIS Transport vesicle TRANS 40

41 Golgi Bodies Modify, sort, & package molecules from ER for storage OR transport out of cell 41

42 Lysosomes Contain digestive enzymes Break down food, bacteria, and worn out cell parts for cells 42

43 Cilia & Flagella Made of protein tubes called microtubules Function in moving cells, in moving fluids, or in moving small particles across the cell surface 43

44 Cilia & Flagella Cilia are shorter and more numerous on cells Flagella are longer and fewer (usually 1-3) on cells 44

45 Cell Movement with Cilia & Flagella 45

46 Which organelle is sort of like the FedEx of the cell? A) Cytoskeleton B) Nucleolus C) Rough ER D) Golgi Bodies

47 Which Organelle is responsible for breaking down cellular waste? A) Lysosome B) Ribosomes C) Rough ER D) Golgi Bodies

48 Which Organelle is involved in cell movement but does NOT change cell shape? A) Cell Wall B) Plasma membrane C) Cytoskeleton D) Cilia and Flagella

49 Fluid filled sacks for storage Small or absent in animal cells Plant cells have a large Central Vacuole No vacuoles in bacterial cells Vacuoles 49

50 Vacuoles In plants, they store Cell Sap Includes storage of sugars, proteins, minerals, lipids, wastes, salts, water, and enzymes 50

51 Chloroplasts Found primarily in plants Contain chlorophyll Use energy from sunlight to make own food via PHOTOSYNTHESIS 51

52 Chloroplasts Surrounded by double membrane Outer membrane smooth Inner membrane modified into sacs called Thylakoids Thylakoids in stacks called Grana & interconnected Stroma gel like material surrounding thylakoids 52

53 Chloroplasts Contains its own DNA (just like mitochondria!) 53