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Warm up. List two things that you know about a cell. List three parts that all cells have in common. Use your notes from Tuesday & Wednesday. 4-1 Notes: History of Cell Biology. Cells. Smallest unit that can perform life processes Random Facts
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Warm up • List two things that you know about a cell. • List three parts that all cells have in common. • Use your notes from Tuesday & Wednesday
Cells • Smallest unit that can perform life processes • Random Facts • Average human is composed of 100 trillion cells • It would take 50 cells to cover the dot of an “i” on your paper
1. Hook, 1665 • Discovered cells while looking at cork (plant cells) • Described them as tiny boxes or rooms • “cell” means little rooms in Latin • Thought cells only existed in plants and fungi
2. Leuwenhoek, 1673 • Observed pond scum & found single-celled organisms • One of the first to look at living cells • He called them “animalcules”
150-200 Year Gap??? • Between the Hooke/Leuwenhoek discoveries and the mid 19th century, very little cell advancements were made. • This is probably due to the widely accepted, traditional belief in Spontaneous Generation. • Examples: -Mice from dirty clothes/corn husks -Maggots from rotting meat
19th Century Advancement • Much doubt existed around Spontaneous Generation • Conclusively disproved by Louis Pasteur
3. Schleiden, 1838 • German botanist • Stated that all plants are made up of cells
4. Schwann, 1839 • German Physiologist • Stated that all animals are made up of cells
5. Virchow, 1858 • German Physician • Studied cellular pathology • Concluded that cells must come from existing cells
Cell Theory 1. All living things are made up of one or more cells (Schleiden & Schwann 1838-39)
Cell Theory 2. Cells are the basic units of structure and function in living things. (Schleiden & Schwann 1838-39)
Cell Theory 3. All cells are produced by the division of existing cells. Virchow (1858)
Warm up • What are the three parts to cell theory? • . • . • . • Did the following Scientist look at living or dead cells? Animal or Plant Cells? • Hooke • Leuwenhoek • Schleiden
Griffin Virtual Lab with Mr. Lee • Live Linkhttps://losal.adobeconnect.com/lee, Saturday October 17, 1pm-2pm • Recording: https://goo.gl/nYfL5A • Join Mr. Lee's Griffin Virtual Lab Remind by texting the phrase @biogvl to the number 81010 • Griffin Lab in the Media Center • Mrs. Gur will be in the Media center Thursdays 2:30-4pm
Prokaryote Eukaryote
Type of Cells Type of Cells • Prokaryotic: lack membrane-bound organelles • Unicellular • Simple • Capsule, cell wall, cell membrane • Nucleoid (DNA) • Cytoplasm • Ribosomes • Cilia, flagella • Oldest living cells • Ex: bacteria
Type of Cells Type of Cells • Eukaryotic: contain a membrane-bound nucleus and organelles • Unicellular and multicellular • More complex a. Ex: Plant and animal cells
All Cells have the following in Common 1. Plasma Membrane • Acts as a barrier to the outside world • Semi-permeable: Allows only certain materials to leave and enter
All Cells have the following in Common 2. Cytoplasm • Gel like substance • Fills space between nucleus and organelles • Most reactions happen here 3. DNA • Control Center • Regulates cells function 4. Ribosomes • Used in DNA Synthesis
Warm up • List the function and location, in the cell, of the following organelles. Denote whether the organelle is found in Plant Cells, Animal Cells, Prokaryotes or All Cells, • Mitochondria • Chloroplast • Ribosome • Cell Membrane QUIZ THURSDAY! (10/22) EXAM THURSDAY (10/29)
Organelles Cell Membrane (Plasma Membrane) Made of phospholipids The phospholipids form a bilayer creating a nonpolar center and a polar out and inner surface Controls what gets in and what gets out of the cell Proteins in the Cell Membrane Integral proteins – proteins inside the membrane, either on one side, inside, or all the way through. Peripheralproteins – proteins found on just one side of the membrane The proteins receive messages, send signals across the membrane, help with transport, etc
Organelles, Cont. Nucleus Protects the cell’s genetic information Chromatin: the form of DNA that is actively used when a cell is not dividing Chromosome: the condensed form of DNA where it is wrapped up tightly with proteins during cell division Ribosomes Organelles made of protein and RNA that direct protein synthesis in the cytoplasm Found in the Cytoplasm, Nucleus and on the Rough Endoplasmic Reticulum.
Organelles, Cont. EndoplasmicReticulum System of membrane tubes and sacs that transport materials around the cell and help synthesize some substances. Rough ER: covered in ribosomes, and produces phospholipids and proteins Smooth ER: lacks ribosomes, and produces lipids like cholesterol and steroids GolgiApparatus Flattened membrane sacs that receive vesicles from the ER and retag the vesicles for delivery in or out of the cell
Organelles, Cont. Vesicles Membrane sacs that store or transport different substances Lysosome: vesicles that contain digestive enzymes that clean, digest food and sometimes break down old cells or organelles There are other kinds of Vesicles including storage and peroxisomes
Organelles, Cont. Mitochondria Converts energy from being stored in organic macromolecules to a usable chemical energy currency, ATP ATP: Adenosine Triphosphate, the chemical used by cells as an energy source for reactions and work Mitochondria have a double membrane and their own DNA. This allows Mitochondria to replicate on their own as needed.
Organelles, Cont. Cytoskeleton A network of microtubules and micro filaments that give the cell support and shape. It also acts as a series of tracts for organelles to travel on around the cell. Also, assist in cell division and help with cell movement. The filaments and tubules are made out of proteins. Cilia: short hair like structures that line the outside of some cells. Used for movement and manipulating things outside the cell. Flagella: Long whip like structures on the outside of some cells that propel the cell in one direction.
Plant Cells Plants are eukaryotes but have 3 unique differences. Photosynthesis vs. Respiration: Many students think that plants undergo only photosynthesis to make food, and animal cells use the food for energy. However: -plant cells undergo cellular respiration also -They use food made during photosynthesis -Lucky for us, plants make more food than they use
Plant Cells: Cell Wall Cell Wall The cell wall is made from the carbohydrate cellulose. It is rigid and gives the plant strength. Pores in the cell wall: Small holes allow some things to move through. Water, ions and some molecules (those small enough) may pass through
Plant Cells: Central Vacuole Central Vacuole Stores lots of water, enzymes, metabolic wastes and other materials. Vacuoles may make up as much as 90% of the cell. Toxic or Pigment Vacuoles: Some plants like Tobacco store toxic chemicals (like nicotine) in their vacuole to discourage predators Some plants store color pigments (like the color of a rose petal)
Plant Cells: Plastids Plastids Organelles similar to Mitochondria because they have a double membrane and their own DNA. Example: Chloroplast and Chromoplast. • Chloroplasts: • Organelle responsible for photosynthesis • Contain pigments that absorb light energy • Reproduce on their own just like Mitochondria
13. Centrioles • Aid in cellular division
14. Lysosomes --vesicles used to digest --recycle old cell parts and kills bacteria --contain degrading enzymes (to "lyse" means to dissolve) TAY-SACHS disease – missing an enzyme of the lysosomes that breaks down a fatty substance. Over time this fat builds up in the brain and nervous tissue, smothering the cells. Results in degeneration and death.
