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1. Cell Structure and Biology Advanced Placement Biology
Chapter 6
Mr. Knowles
Liberty Senior High School
2. Robert Hooke, 1665
3. Hooke’s First Microscope
4. History of the Cell 1665- Robert Hooke described cork as composed of cellulae (cell).
A few years later-Anton van Leeuwenhoek described live cells.
1838 and 1839- Schleiden and Schwann developed the cell theory.
5. Schleiden and Schwann- Cell Theory All organisms are composed of cells or at least one.
Cells are the smallest unit of life (a collection of metabolic processes + heredity).
All cells come from other cells. None spontaneously arise.
6. Different types of microscopes
Can be used to visualize different sized cellular structures
7. Use different methods for enhancing visualization of cellular structures
9. The scanning electron microscope (SEM)
Provides for detailed study of the surface of a specimen
10. The transmission electron microscope (TEM)
Provides for detailed study of the internal ultrastructure of cells
11. The process of cell fractionation
13. What’s the world’s largest living cell? Surface to Volume Ratio
14. A smaller cell
Has a higher surface to volume ratio, which facilitates the exchange of materials into and out of the cell
16. Prokaryote vs. Eukaryote Archaebacteria and Eubacteria.
Lack membrane-bound organelles.
DNA in a nucleoid region.
Have plasma membrane.
Cell wall of peptidoglycan.
Use 70S ribosome.
Unique flagella-flagellin protein.
Animalia, Plantae, Protista, Fungi.
Have true membrane-bound organelles.
DNA in a nucleus.
Have plasma membrane.
Plants and some protists have a cell wall of cellulose.
Use different ribosomes.
17. Cell structure is correlated to cellular function
18. A Composite Eukaryotic Cell
19. A animal cell:
23. A plant cell:
25. Corn Plant Cell
26. Show me some cell biology animation!
27. Other Differences Between Plant and Animal Cells?
28. Click below for a good tutorial review of Prokaryotic, Plant and Animal Cells
29. The plasma membrane:
Functions as a selective barrier
Allows sufficient passage of nutrients and waste
30. Plasma Membrane
31. Cytosol and Membranes
32. What is the function of organelles? To compartmentalize chemical reactions that may proceed simultaneously.
To provide membranes on which to catalyze reactions.
33. Nuclear Envelope
Encloses the nucleus, separating its contents from the cytoplasm
34. EM of Nucleus
35. Nuclear Envelope
36. Nuclear Membrane
37. 1. The Nucleus Largest organelle, centralized in animal cells.
Stores and protects the cell’s genetic information.
Surrounded by two phospholipid bilayer membranes-nuclear envelope.
Where both layers are fused - nuclear pores + transport protein.
38. Nucleus and Nuclear Pore
40. What is the nuclear pore complex and what does it do?
41. How is the ribosome assembled and what does it do?
42. Do all cells have nuclei?
44. Organization of Nuclear DNA
45. Show me how DNA is packaged and organized!
46. Let’s take a look inside a cell! http://www.life.uiuc.edu/plantbio/cell/
47. The Nucleolus Site within the nucleus of ribosomal subunits are manufactured- rRNA + ribosomal proteins.
Ribosomes leave the nucleus as subunits through the nuclear pore and are later reassembled.
May be free (in the cytoplasm) or attached to the ER (rough ER).
48. The Nucleolus of an Algae Cell
49. Carry out protein synthesis
50. The Ribosome (40S and 60S)
52. Rough ER EM
53. Endoplasmic Reticulum (ER) Means “little net within the cytoplasm”
Internal membrane system with a lipid bilayer + proteins.
Weaved in sheets- forming channels.
Outer membrane of the nuclear envelope is continuous with the ER membrane.
Some regions have embedded ribosomes.
54. The ER Membrane
Is continuous with the nuclear envelope
55. The ER can Grow!
56. Two Types of (ER) 1. Rough ER: heavily studded with ribosomes- protein synthesis. Proteins have signal sequences which direct to a docking site on the surface of the ER.
2. Smooth ER: lack ribosomes; have enzymes embedded in membrane for carbohydrate and lipid synthesis.
3. Both secrete finished products in transport vesicles.
57. EM of Pancreas Cell + ER
58. Functions of Smooth ER The smooth ER:
Synthesizes lipids
Metabolizes carbohydrates
Stores calcium
Detoxifies poison
60. The Golgi Complex Flattened stacks of membranes in the cytoplasm-cisternae.
Collection, packaging and distribution of proteins and lipids.
Transport vesicles from RER and SER fuse with the Golgi membrane.
61. Functions of the Golgi Apparatus
62. Transport of Proteins
63. Proteins Leaving the Golgi
64. The Golgi Complex Proteins (from RER) may have short sugar chains added--> glycoproteins.
Lipids (from SER) may have short sugar chains added-->glycolipids.
Both collect at flattened ends-cisternae.
Cisternae membranes pinch off the glycoproteins and glycolipids into secretory vesicles (liposomes).
Liposomes may fuse with plasma membane or organelle membranes.
65. Show me some Golgi in action!
66. Lysosomes in Action!
68. Macrophages use Lysosomes
69. Lysosomes
70. Lysosomes carry out intracellular digestion by
Phagocytosis
71. Lysosomes Membrane-bound organelle with digestive enzymes.
Breakdown protein, nucleic acid, carbos, lipids.
Digest old organelles and invading bacterial cells.
Digestive enzymes only active at low pH.
72. Autophagy
73. Lysosomes Inactive lysosomes-Primary Lysosomes, high pH, enzymes are inactive.
Once fused with food vacuole- pump H+ into compartment- active, Secondary Lysosomes.
Involved in normal cell death and programmed cell death (apoptosis).
Ex. Tadpole tail tissue; webbing between human fingers.
75. Peroxisomes: Oxidation Peroxisomes:
Produce hydrogen peroxide and convert it to water.
76. EM of Peroxisome
77. Relationships among organelles of the endomembrane system
78. Mitochondrion EM
79. EM of a Mitochondrion
80. Mitochondria
81. Let’s take a look inside a cell! http://www.life.uiuc.edu/plantbio/cell/
82. Mitochondrion (ia) Rod-shaped organelle, 1-3 micrometers long.
Bounded by two membranes- outer is smooth; inner is folded into continuous layers-cristae.
Two compartments- matrix-inside the inner membrane and intermembrane space between the two membranes.
Enzymes for oxidative metabolism are embedded in the inner membrane.
83. Mitochondria are enclosed by two membranes
A smooth outer membrane
An inner membrane folded into cristae
84. Mitochondria Contain a circular piece of DNA for many of the proteins in oxidative metabolism.
Also has its own rRNA and ribosomal proteins--> own protein synthesis.
Involved in its own replication.
Circular DNA? Two membranes? Own Genes? Own replication?
What does that sound like?
85. The Plastids Chloroplasts
Leucoplasts
Amyloplasts
Chromoplasts
86. EM of Chloroplast
87. Chloroplast EM
88. Chloroplasts
Are found in leaves and other green organs of plants and in algae.
89. Chloroplasts Algae and plants have organelles for photosynthesis.
Two membranes- outer and inner membranes.
A closed, stacked network of membranes-granum (a).
Fluid-filled space around grana-stroma.
Disc-shaped structures-thylakoids.
Light-capturing enzymes are embedded on thylakoids.
90. Chloroplasts Have DNA which encode many enzymes necessary for photosynthesis.
Do all plant cells have chloroplasts?
May lose internal structure-leucoplasts.
A leucoplast that stores starch-amyloplast. Found in root cells.
A leucoplast that stores other pigments-chromoplasts.
91. Centriole
92. Centriole Barrel-shaped organelles in animals and protists, NOT plants.
Usually found in pairs around the nuclear membrane.
Hollow cylinders made of microtubules (protein). Have their own DNA.
Help move chromosome during cell division.
93. Some Other Organelles Central Vacuole or Tonoplast: in plants, for protein, water, and waste storage.
Vesicles: in animals, usually smaller sacs used for storage and transport of materials.
94. Central Vacuoles
Are found in plant cells
Hold reserves of important organic compounds and water
95. Paramecium Contractile Vacuole
96. Laser Scissors and Tweezers!
97. Ovaetching and Gene Deletion with Lasers
98. The Cytoskeleton!
99. Cytoskeleton
Is a network of fibers extending throughout the cytoplasm
100. There are three main types of fibers that make up the cytoskeleton:
103. Actin Filaments Made of globular protein monomers- actin
Actin monomers polymerize to form actin filaments
Filaments are connected to proteins within the plasma membrane.
104. How do you put actin together?
105. Actin Filaments Actin filaments are thinner, cause cellular movements like ameboid movements, cell pinching during division.
Provide shape for the cell.
106. Actin that function in cellular motility
Contain the protein myosin in addition to actin
107. Amoeboid Movement
Involves the contraction of actin and myosin filaments
108. Ameboid Movements
109. White Blood Cell + Bacteria
110. Actin forms Pseudopodia in Macrophages
111. Actin allows cells to grow- Root Hair Cell Growth
112. Actin permits cells to change shape- Fish cell ruffle and fish cell lamellipodia.
113. What is cytoplasmic streaming?
114. Cytoplasmic Streaming
Is another form of locomotion created by microfilaments
115. So you want to see some actin in action?
117. Microtubules 2 globular monomers- ? tubulin and ? tubulin polymerize to form 13 protofilaments
Filaments form wide, hollow tubes- microtubules.
Form from nucleation centers (near nucleus) and radiate out.
118. Show me microtubulin and microtubles!
119. A Microtubule
120. Treadmilling of a Microtubule
121. Microtubules Constantly polymerize and depolymerize- GTP-binding at ends.
Ends are + (away from center) or - (toward center).
Cellular movements and intracellular movement of materials and organelles.
122. Show me REAL microtubular treadmilling!
123. Microtubules Use specialized motor proteins to move organelles along the microtubule.
Kinesins- move organelles toward the + end (toward cell periphery)
Dyneins- move them toward the - end (toward the center of cell)
125. How kinesins and dyneins work!
126. Microtubule and Motor Proteins
127. One more look at how a kinesin works!
128. How do kinesins work?
129. How do dyneins work?
130. A Working Model of Dynein Function
131. Microtubules and Motor Proteins Rearrange Organelles
132. Microtubules are important in camouflage. They move melanophores in fish epidermis.
133. Show me the microtubules!
134. Could a simple defect in a kinesin affect a whole organism?
135. Wild-type Drosophila larva
136. Wild-type (Normal) Drosophila Movement
137. Mutant Kinesins in Drosophila (khc6 mutant)
138. EM of Intermediate Filaments
140. Intermediate Filaments Most durable protein filament- tough fibrous filaments of overlapping tetramers of protein (rope-like).
Between actin and microtubules in size. Stable
Ex. of Fibers- vimentin and keratin
141. Intermediate Filaments Anchored to proteins embedded into plasma membrane.
Provide mechanical support to cell.
142. Growing Intermediate Filaments
143. Structural Support…that’s what I’m talking about!
144. Plant Cell Walls
Are made of cellulose fibers embedded in other polysaccharides and protein
May have multiple layers
145. Plants: Plasmodesmata Plasmodesmata
Are channels that perforate plant cell walls
146. The Extracellular Matrix (ECM) of Animal Cells Animal cells
Lack cell walls
Are covered by an elaborate matrix, the ECM
147. The ECM
Is made up of glycoproteins and other macromolecules
148. Types of Intercellular Junctions in animals
149. Cilia
