Nov 17/18

Bellringer: Explain what is meant by "the cell is the most basic unit of life."
Objective: Students will understand cell structure related to function.
-the smallest thing that can be alive: the cell

Gene Control: Go to . Login: jacobong@gmail.com ; password: biology. Search for: gene control. Watch the video from: Gene Control
The development of creatures that appear to have nothing in common is directed by a surprisingly small number of genes. In this video segment, learn about the power of master control genes. Footage from The Secret of Life: "Birth, Sex & Death."

Control genes: these genes tell a certain cell to become the spinal chord (or some other structure.

Take notes: Look at a macrophage engulfing bacteria. A long time ago people did not know about cells. They did not know that a single cell divided and became many more cells. Robert Hook was the first one to find a cell.
-Cell theory: 1. all organisms are composed of cells. 2. All cells come from other pre-existing cells. 3. The cell is the most basic unit of life (life doesn't exist below the level of a cell). From an evolutionary standpoint, we need to know the difference between the two different type of cells. The prokaryote does not have a nucelus AND DOES NOT HAVE ANY ORGANELLELS. Bacteria are prokaryotes and the biggest difference between plant and animal cells and bacteria (and other prokaryotes) are that prokaryotes DO NOT HAVE ORGANELLES.
-Cell theory started with Mr. Hook who saw cells in cork cells (that reminded him of the 'cell' of a monastery). He found other cells in other living things. Then Leuwenhook then made a better microscope. Other scientists added to cell theory (only living things were made out of cells).
Cell Theory is not Cell Fact but is also no longer Cell Hypothesis. Now take notes on organelles.

Why study cells? Cells make up tissue make up organs which make up bodies. Bodies are made up of cells. Cells divide in eukaryotes. (REmember how earlier we talked about atoms and macromolecules, eventually we will learn about tissues and organ systems. There is a hierarchy). What do cells do? (See the slide called "The Work of Life". Breathing means that every cell is breathing. Eating means that at the cellular level cells take in and digest food.

Cell membrane ("the gatekeeper", doorperson, bouncer): organelle number one. Function: separates cells from outside. Controls what enters or leaves the cell (O2, CO2, food, water, nutrients, waste). Recognizes signals from other cells (allows communication between cells). Structure: (here we use lipids). Double layer of fat (phospholipid bilayer. A phosphate attached to the lipid tails (the fatty acids). The phosphate is hydrophilic (likes water) but the tail is hydrophobic (dislikes water). So the fatty acids are going to align up away from fluid and that is how the membrane is formed. (Macrophages search for markers on other cells to determine if it is an invader or part of the body. If an invader, then macrophages will engulf/eat the cell.)

Picture of the cell with box pointing to a cell membrane. Write down: cell membrane=cell boundary, controls movement of materials in and out, recognizes signals.

Make a list of organelles.
2. Vacuole and vessicles ("like UHaul delivering stuff; also storage sheds": function = transport around cell; storage. structure= membrane sac (phospholipids that form a storage vessicle). If a food particle like starch comes in and the cell needs glucose, then the food enters the cell through endocytosis and then the cell membrane pinches off to form a vessicle. In paramecium, contractile vacuole. Animal cells have food vacuoles.

3. cytoplasm is cell fluid

4. lysosomes (garbage man/recycler). A special type of vessicle. Lyse = to cut or break. (They have digestive enzymes. Food enters and fuses with a lysosome and the digestive enzymes break up the food so that it can be used. Lysosomes also digest broken organelles. If plant cells get to0 full of water, they lyse. If you put cells in pure water (which is hypotonic), then the water will enter into the cell. (One family was charged with killing their daughter with water treatment). Lysosomes breaks stuff down into smaller pieces so that it can be used or disposed of.

5. tHE "MIGHTY" Mitochondria "IS THE POWERHOUSE OF THE CELLS". MAKEs ATP ENERGY FROM CELLULAR RESPIRATION AND IN BOTH ANIMAL AND PLANT CELLS. ATP is an adenosine tri- phosphate, i.e. a modified nucleotide. ATP is the currency for cellular energy. Structure of mitochondria.
MAKES ATP ENERGY FROM SUGAR AND OXYGEN.


6. Chloroplasts. (See how the sugar is an octagon, actually should be a pentagon or hexagon. Chloroplasts: performs phtosynthesis (where energy and sugar are produced from sunglight and other building materials). The equation: sunglith and carbon dixodie ---> ATP and sugar.
ATP is active energy
Sugar is stored energy so the plant can build leaves and roots and fruits out of the sugar.


7. Nucleus: functions=control center of the cell (central processor/computer); protects DNA (the instructions for building proteins).

8. Nucleolus is a ribosome factory
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