Organism of the Day: Kangaroo
Kangaroos are found in Australia and New Guinea.
Kangaroos are marsupials (give premature birth).
Kangaroos have few predators today, however, there are believed to be numerous extinct predators.
Why do baby kangaroos eat from their mothers? What do they obtain?
Kangaroos are strict herbivores, eating various shrubs. Assuming there are 1000 kg of shrub in an area, how many kg of kangaroo could that support? Draw an energy pyramid.
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Biology
Monday December 3, 2012
1. Organism of the Day 2. Continue Notes on Cells
3. Class Quiz
Announcements
Due Today, December 3: Read 7.1 and answer questions 1 ­ 5.
Due Tuesday/Wednesday, December 4/5: Read 7.2 and answer questions ?? ­ ??
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Chapter 7 Notes What's the smallest part of you that is alive?
The Discovery of the Cell
Robert Hooke
Anton Van Leeuwenhoek
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Great for:
1. Small amounts level of magnification 2. Viewing live specimens Drawbacks:
1. Magnification limited
2. Cells tend to be transparent 4
Great for:
1. Viewing small molecules
2. Observing structures in 3­D or thin slices in 2­D.
Drawbacks:
1. Cells/Tissues observed are treated before observing, leading to artifacts.
2. Can only observe nonliving cells.
3. Expensive 5
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Two Cell Types
Prokaryotes and Eukaryotes
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Prokaryotes = Bacteria (mostly)
CHARACTERISTICS
• Simple
• Small
• Cell membrane and cell wall
• No membrane­
bound organelles but do have ribosomes.
• Have DNA, but not in a nucleus
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What bacteria Do:
• Autotrophs
• Produce oxygen
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Fix nitrogen
Recycle nutrients
Form antibiotics
Help in digestions/formation of vitamins
Production of cheese and yogurt
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Two Cell Types
Prokaryotes and Eukaryotes
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Eukaryotes
Characteristics
1. More complex
2. Larger
3. Cell membrane.
4. Membrane bound organelles
5. DNA in nucleus
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PARTS OF EUKARYOTIC CELLS
• Cell wall
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Cell membrane
Lysosomes
Mitochondria
Nucleus Ribosomes
Endoplasmic Reticulum
Golgi Apparatus
Cytoskeleton
Microtubules
Cilia
Know These!!!
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Cell Wall
Support and protects plant and fungi cells. Made of cellulose in plants and chitin in fungi
Plasma Membrane
Controls what comes in/out of a cell.
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Eukaryotes
Organelles are important in keeping non­
compatible reactions separate, yet allowing them to happen at the same time!
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Endocytosis
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Lysosomes
Contain enzymes to break down food brought in by endocytosis; can also break down own molecules for recycling.
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Mitochondria
Break down food to produce adenosine triphosphate, ATP. ATP provides the cell with an accessible source of energy. Can you name a functional group in ATP?
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Nucleus
Contains chromosomes which are DNA wrapped around protein spools. Also contains nucleoli, which are areas where rRNA and tRNA are made.
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Ribosomes
Synthesize proteins
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Endoplasmic Reticulum
A system of tubes that carry proteins to destinations in the cells and alters proteins as they move.
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Golgi Apparatus
Where proteins from the ER are further refined and packaged for final transport.
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Vacuoles
Found in both plant and animal cells; store water, digestive enzymes, salts, pigments, etc.
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Cytoskeleton
A network of protein fibers that help the cell keep its shape and helps things move around (like a freeway).
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Eukaryotic Cells
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Class Quiz
Question 1: What are the three parts to cell theory?
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Class Quiz
Question 2: Two people are associated with the discovery of the cell. Give one of their names.
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Class Quiz
Question 3: Identify a difference between prokaryotic and eukaryotic cells.
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Exit Questions:
NA
Reminders:
Due Tuesday/Wednesday, December 4/5: Read 7.2 and answer questions ?? ­ ??
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