CELL THEORY & FUNCTION
DISCOVERY OF THE CELL Can t see cells, so who knew they existed? Discovered after the microscope was invented. Mid 1600s when scientists began using microscopes Robert Hooke used a microscope to look at a thin slice of cork (a plant material). Cork = thousands of tiny, empty chambers. R.H. said chambers = cells because they reminded him of a monastery s tiny rooms
Today we know cells aren t empty chambers. They contain living matter!
THE CELL THEORY Numerous observations made it clear that cells were the basic unit of life.
CELL THEORY 1. All living things are composed of cells. 2. Cells = basic units of structure and function in living things. 3. New cells R from existing cells.
NOWADAYS Researchers use microscopes and techniques more powerful than before! i.e. Fluorescent labels and light microscopy to follow molecules moving through the cell. Confocal light microscopy, which scans cells with a laser beam, makes it possible to build three-dimensional images of cells and their parts. High-resolution video technology makes it easy to produce movies of cells as they grow, divide, and develop.
PROKARYOTES Smaller & simpler than eukaryotic cells (exceptions to this rule). Prokaryotic cells have genetic material contained in a nucleus. Prokaryotes carry out every activity associated with living things. (grow, reproduce, respond to the environment, some can move by swimming through liquids!) Bacteria are prokaryotes!
EUKARYOTES Larger and more complex. Generally contain dozens of structures and internal membranes, and many are highly specialized. Eukaryotic cells contain a nucleus = genetic material is separated from the rest of the cell. Some eukaryotes = unicellular organisms. Others form large, multicellular organisms (plants, animals, fungi, protists).
COMPARE Prokar yote No Nucleus No Membrane Bound Organelles Bacteria Small (1/10 size of euk) Eukar yote Nucleus Membrane Bound Organelles All other organisms Larger
EUKARYOTES 7-2 Eukaryotic Cell Structure p. 174 1. nucleus 2. nucleolus 3. nuclear membrane (envelope) 4. cytoplasm 5. chromosomes 6. cell membrane 7. endoplasmic reticulum (rough) 8. ribosome 9. Golgi apparatus (body) 10. mitochondria 11. lysosome 12. chloroplast 13. cell wall 14.Vacuole 15 Nucleoplasm 16 endoplasmic reticulum (smooth) 17. Nucleoli 18. centrioles
Chloroplast pg. 208 Photosynthesis 6 CO 2 + 6 H 2 O + energy carbon dioxide water sun C 6 H 12 O 6 + 6 O 2 glucose oxygen
PHOTOSYNTHESIS
Typical Plant Cell
CELLULAR RESPIRATION
CELLULAR RESPIRATION What is it? Cell. Res. = a process that transforms sugars we eat and oxygen into useable energy (ATP), water and CO2. Where does it happen? It happens in the cell. Organelles = Mitochondria Which organisms use it? All animal eukaryotes use it to create energy. (Single cell and multi-cell) What do we call organisms that can not make their own food? Consumers / Heterotrophs
QUESTION FOR UNDERSTANDING How is it possible for the plant and the fish to survive in this closed ecosystem where oxygen can not enter or escape? Why would an enclosed ecosystem based on land be harder (not impossible) to create?
Typical Animal Cell
QUESTION Why do plant cells need BOTH chloroplasts and mitochondrion? Why do animal cells only have mitochondrion?
QUESTION Understanding how mitochondrion work, what cell would you expect to have more mitochondrion present in a bird: An eye cell A muscle wing cell A foot cell?
BELL RINGERS 1-Mitochondria and Chloroplasts- For marks (homework) 2-Concept: Photosynthesis and Respiration- For marks (homework) 3-Thinking critically about photosynthesis: in class, review in class, good source for short answer questions on a test 4-`The Chloroplast- for notes, answers will be on the website
CELL QUIZ 1. Contains digestive enzymes. 2. Control center. 3. Provides structure in a plant cell. 4. Contains chlorophyll. 5. Carbohydrate producers. 6. Stores, modifies, transports materials. 7. Storage organelle. 8. Pathway through cell. 9. Tiny internal support structure. 10. Power house. 11. Allows certain things in and out of a cell. 12. Many of these in muscle cells. 13. These cells are special because they do not have a nucleus. 14. Make ribosomes. 15. Involved in cell reproduction. 16. These cells are special because they have DNA in a nucleus.
BELL RINGERS 7.2 (pg. 174-181)