Cells!

CA Standards Cell Biology 1.c. Students know how prokaryotic cells, eukaryotic cells (including those from plants and animals), and viruses differ in complexity and general structure.

The History of Microscopes and Cell Theory

Janssen produced 1st microscope 1595

1665 Robert Hooke drawing of cork 1665 Robert Hooke drawing of cork. Called chambers cells because they reminded him of tiny rooms in a monastery.

Plant cells 1838: Mattias Schleiden discovered plants are made of cells.

1839 Theodor Schwann claimed animals are also made of cells

1858: Rudolf Virchow stated that living cells come only from other cells.

The Cell Theory Schwann Schleiden Virchow The observations of Schleiden, Schwann, and Virchow form the cell theory.

The Cell Theory All living things are made of one or more cells. Cells are the basic units of structure and function in organisms All cells arise from existing cells The Cell Theory

Our objective: Compare and contrast how prokaryotes, eukaryotes, and viruses differ in structure and function.

What is a cell? The smallest structural and functional unit of all living organisms.

2 Types of Cells Prokaryotic Eukaryotic

Prokaryotic Eukaryotic 2 Types of Cells Pro = first; kary= cell Eu= true; kary= cell

All living things…. Are either prokaryotic or eukaryotic.

Prokaryotic vs. Eukaryotic Smaller, simpler Larger, complex

Do you think we are prokaryotes or eukaryotes and why???

Prokaryotic Cells Who? Unicellular bacteria (one-celled) What? No true nucleus One circular DNA No membrane-bound organelles First lived at least 3.5 billion years ago

Prokaryotes A bacterium is a prokaryotic cell

Fig.3: Prokaryotic Cell (Bacillus megaterium)

Some bacteria have Flagella Long, threadlike structures which enable movement.

Bacteria are important to all life on Earth. They… Decompose dead things. Fix nitrogen in the atmosphere to make it available to plants. Digest sewage. Break down oil from oil spills. Synthesize medicines. Help animals (including us) digest food. Some cause disease.

Copy, color and label the Prokaryotic Cell (p. 472) Period 4 stopped here 9/27/10

Eukaryotic Cells Who? Fungi What? Plants Animals What? True nucleus with nuclear membrane DNA (genes) located in nucleus Membrane-bound organelles Complex structure and function Evolved 2.5 billion years ago

Fig. 1: Eukaryotic Cell (Mouse Cell)

Fig. 2: Candida albicans- Yeast (Eukaryotic Cell)

Plant Cell

Copy, color and label the Eukaryotic Animal Cell (p. 175) A= Rough E.R. (Endoplasmic Reticulum) B= Cytoplasm C= Golgi apparatus D= Nucleolus E= Nucleus F= Mitochondria G= Smooth E.R. H= Ribosome I= Cell membrane

Copy, color and label the Eukaryotic Plant Cell (p. 175) G A= Cell Wall B= Nucleus C= Cell Membrane D=Rough E.R. E= Chloroplast F= Vacuole G=Mitochondria H=Golgi apparatus H

Make a Venn Diagram Comparing and Contrasting Eukaryotes and Prokaryotes

Common Features of Eukaryotic and ProkaryoticCells Cell membrane- encloses and protects the cell Cytoplasm- interior fluid of cell Cytoskeleton – microscopic fibers within cytoplasm Ribosomes- structure on which proteins are made (Eukaryotic Ribosomes are larger and more complex) DNA- provides instructions for making protein, regulate cellular activity and reproduce. (Eukaryotic DNA is more complex)

Cell Animation http://www.learnerstv.com/animation/animation.php?ani=162&cat=biology

Viruses! Not cells… Not alive…. So what are they? A virus is a tiny particle made of nucleic acid (genetic material), protein and sometimes lipids that can only replicate by infecting living cells. Most viruses are composed of a core of either DNA or RNA surrounded by a protein coat called a capsid. Viruses are NOT alive: They don’t grow, develop, or carry out respiration. They do not have organelles or a nucleus.

They come in a variety of shapes and sizes. Viruses may have only a few genes or over 100 genes. They come in a variety of shapes and sizes.

Viruses enter cells and use the cell to make copies of themselves, often destroying the cell in the process. Lytic Infection- virus enters cell, uses the cell’s energy, makes copies of itself and causes the cell to burst. Lysogenic Infection- virus enters cell, embeds its DNA into the DNA of the host cell and replicates itself- indefinitely or it may switch to the lytic cycle.

Viruses cause many human diseases. Polio Measles AIDS Mumps Influenza Yellow fever Rabies The common cold Herpes Hepatitis Genital Warts

Bacteria cause many human diseases and problems. Tuberculosis Strep throat Scarlet fever Diptheria Lyme disease Tooth decay Meningitis Chlamydia Gonorrhea Syphilis

Make a Venn Diagram Comparing and Contrasting Cells and Viruses (use page 483 for help!)

Key points Prokaryotes have no membrane bound organelles. Eukaryotes have membrane bound organelles allowing for thousands of chemical reactions to occur at once. Viruses are not cells; they consist of only a protein coat surrounding a strand of genetic material, either RNA or DNA.

TEST PRACTICE! Eukaryotic cells are different from prokaryotic cells because eukaryotic cells A are much smaller. B have permeable membranes. C have a higher rate of reproduction. D have nuclei.

TEST PRACTICE! Which of these best completes this concept map? A an animal cell B a prokaryotic cell C a virus D a plant cell

HOMEWORK: Read 19-1, 19-2 and 19-3 on Bacteria and Viruses and answer the Section Review questions. (15 pts) DUE: TUESDAY! Work on Cell Model Read 7-1 Read 7-2 and Answer Section Review Questions in notebook (5 pts)

Eukaryotic Organelle Chart Complete the chart and label the diagrams.

Eukaryotic Cell Model 30 points Choose an animal cell or a plant cell. Create a 3-D model of that cell, including all organelles. (15 pts) Either label the model directly or create a key for the model. (5 pts) You will be graded on creativity and likeness (how close it resembles a real cell). (10 pts) For extra credit (10 pts), create a bacterial cell (prokaryote) in addition.