UNIT 1- THE CELL
CELL THEORY & FUNCTION
A Word From Bill
Record your observations about the picture to the right. What do you think you are you looking at? Describe the structure with as much detail as possible? Is there organization to what you see? Is it a single unit or many units?
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!
SCIENTISTS OF CELL THEORY Robert Hooke-First to observe cells. (1665) Anton van Leeuwenhoek- first to observe living cells.(1674) Matthias Schleiden- first to state plants are made of cells. (1838) Theodore Schwann-animal tissues are made of cells. (1839)
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.
CELL SIZE LIMITS Cells need to be small for the purposes of diffusion of materials into and out of the cell across the cell membrane. The cell membrane surface area-to-volume ratio limits how large a cell can be in order be able to perform metabolic functions. As a cell gets larger the volume of the cell increases at a faster rate then the radius. If the cells radius increase 10 times the volume will increase by 100 times
CELL SHAPE A cells shape reflects the different functions of cells. Each cell shape has evolved to allow the cell to effectively perform its job. A nerve cells has long extensions that reach out in various directions for sending and receiving nerve impulses A Skin cell is a flat, platelike cells that protect the surface of the body.
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).
PROKARYOTE VS EUKARYOTE
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 endoplasmic reticulum (smooth) 16. centrioles
ORGANELLE REVIEW GAME
Q/A Review: What is the difference between a eukaryote and a prokaryote?
CELL ORGANELLES An organelle (tiny organ)- is well-defined, intracellular body that performs specific functions for the cell.
CYTOPLASM The cytoplasm is the region of the cell inside of the cell membrane. It includes: fluid, the cytoskeleton and all organelles except the nucleus.
CELLULAR ORGANIZATION Unicellular-One celled organism Multicellular-many celled organism Over time cells began to form groups that functioned together to create multicellular organism.
TYPE OF UNICELLULAR MOVEMENT Cilia-tiny little hair like structures. Flagella- Whip-like tail. Psuedopodia- false foot extension of the cytoplasm.
BELL RINGER Where does most energy come from? How do you get energy? What processes are involved with you obtaining energy. (list as many as possible)
OVERVIEW All living things need energy to survive. Almost all of the energy used by organisms comes from the sun. Organisms that can use the sun to create food are called autotrophs. Auto-self Troph-feeding Examples include: algae, plants, some protists and some prokaryotes. Even organisms that are not autotrophs rely on autotrophs for energy either directly (herbivores) or indirectly (higher level consumers). Heterotrophs- must get energy from the food they eat.
PHOTOSYNTHESIS Photosynthesis is a series of complex chemical reactions that converts light energy from the sun into chemical energy in the form of organic compounds (i.e. carbohydrates).
PHOTOSYNTHESIS The molecules used (reactants) during photosynthesis include: Carbon Dioxide (CO 2 ), Water (H 2 O) The molecules created (products) include: Glucose (C 6 H 12 O 6 ), Oxygen O 2
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
FACTORS THAT AFFECT PHOTOSYNTHESIS
Typical Plant Cell Video
CELLULAR RESPIRATION
CELLULAR RESPIRATION When you eat food you get energy from breaking that food down into simpler molecules. Cellular Respiration-a complex process in which cells make ATP (adenosine triphosphate) by breaking down organic compounds. BOTH autotrophs (plants) and heterotrophs use Cellular Respiration.
CELLULAR RESPIRATION The products of cellular respiration are the reactant of photosynthesis. Cellular Respiration is divided into 3 stages. Glycolysis Aerobic Respiration (with oxygen)-krebs cycle Electron Transport Chain The main focus is to get ATP (adenosine triphosphate) the universal energy molecule. It is like money.
ATP ATP is the universal energy currency in the cell. It has 3 phosphate groups attached. It is high energy molecule. When it releases a phosphate group it releases energy and it becomes ADP (adenosine diphosphate).
WHERE DOES CELLULAR RESPIRATION OCCUR? It occurs in the cytoplasm (glycolysis) and the mitochondria. Video
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?
CELLULAR RESPIRATION VS PHOTOSYNTHESIS FOLDABLE
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)