Honors Introduction to the Cell PDF

Introduction to the Cell Cells are the basic units of structure and function in life  The Discovery of Cells Anton Van Leeuwenhoek Dutch Biologist (1632-1723) First person to observe living cells through a Simple microscope  The Discovery of Cells Robert Hooke (1635-17...

Introduction to the Cell Cells are the basic units of structure and function in life  The Discovery of Cells Anton Van Leeuwenhoek Dutch Biologist (1632-1723) First person to observe living cells through a Simple microscope  The Discovery of Cells Robert Hooke (1635-1703) Examined plants cells in a thin slice of a cork and saw little boxes 🡪dead plant cell. Robert Brown- observed dark circles in the center of the cell 🡪 Nucleus Development of the cell Theory Matthias Schleiden Theodor Schwann German Scientist German scientist In 1838 he used a Observed many microscope to study different animal cells plant parts Concluded that all Concluded that all animals were made plants were made up up of cells. of cells. Together Schwann and Schleiden were convinced that all living things were made up of cells. Development of the cell Theory Rudolph Virchow German doctor hypothesized that new cells do not form on their own. Stated that every cell that is or has ever been, came from a cell that already existed.  Not in notes The Cell Theory The cell theory is one of the major theories in science It is not based on the hypothesis and observations of only one person. And is the basis for scientists that study the parts of the cell, cell organization, and how cells reproduce and change through time.  The Cell Theory States: All living things are composed of one or more cells. Cells are the basic units of structure and function in an organism. Cells come only from the reproduction of existing cells. Developments in Cell Biology Cell Biology developed as improvements in technology helped scientist unlock the secrets of cells Microscopes clarified the definition of life. All living things consist of/they: ❖Organized parts ❖Obtain and use energy ❖Perform chemical reactions ❖Change over time ❖Homeostasis ❖Respond to their environment ❖Reproduce ❖Share a common history  Cell Diversity Not all cells are alike. Cells within one organism may show enormous diversity in: Size Shape Organization Variety in functions Cells in most multicellular organisms are organized into: Tissue: -groups of cells that carry out specific functions ex. Epithelial tissue & muscle tissue Organs: -several types of tissue that interact to perform a specific function ex. Stomach Organ systems: -made up of a group of organs that work together to perform a set of related tasks. ex. Digestive system  Hierarchical organization of Life ▪ Atom molecule cell tissue ▪ Organism organ system organ ▪ Population community Ecosystem  Prokaryotic cells: ❑Unicellular organisms ❑Lack a nucleus and membrane-bound organelles. (nucleoid region instead) ❑Genetic information can be concentrated in one part of the cell. Prokaryotic Cells some have: -flagella, for movement - pili/fimbriae attach to surfaces Divide to reproduce: binary fission example: E. coli Streptococcus Eukaryotic cells: Contain a membrane bound nucleus & organelles examples: plant and animal cells Plant Cell Animal Cell  Cell Facts Not in Notes A cell cannot survive if it is totally isolated from its environment A cell must take in nutrients and other materials to survive A cell must also dispose of the wastes that they produce Most cells are visible only with a microscope. Cells contain a variety of internal structures called organelles. An organelle is a cell component that performs specific functions for the cell. Cell Structures All cells have 1) cell membrane - outer boundary of cell 2) Genetic information - DNA 3) cytoplasm - watery material inside cell membrane containing dissolved substances, enzymes, organelles and structures Prokaryotic Cells Worksheets pg. 3-5 Use your time wisely in class as you also have Vocabulary section 1 (20 words) due tomorrow Do now: Page 6 in note packet Circle the letter of each sentence that is true about prokaryotes. a. They grow and reproduce b. Many are large multicellular organisms c. They are more complex than cells of eukaryotes d. They have a cell membrane and cytoplasm. Are all Eukaryotes large, multicellular organisms? Category Definition Examples Organisms whose cells lack nuclei Organisms whose cells contain nuclei 3 Components of the Cell Theory 1. All living organisms are composed of ____________ 2. Cells are the _________________ of structure and function in living organisms 3. New _________ are produced from _______ cells 21 The Cell Membrane (or plasma membrane) selectively permeable - regulates what enters and leaves the cell and helps with protection and support made of phospholipid bilayer embedded with ○ proteins that act as channels & pumps ○ carbohydrates act as chemical ID cards The fluid-mosaic model  Cell Wall ❑found in plants, algae, some bacteria, and fungi ❑surrounds the cell membrane ❑protects and supports the cell  Cell Wall ❑allows substances to pass through ❑made of cellulose in plants ❑2 layers: Primary & Secondary  Nucleus Lets label! One of the largest organelles, found near the center of the cell surrounded by nuclear envelope with nuclear pores contains small dense region called nucleolus which is made of RNA and proteins, makes ribosomes  contains genetic information in structures called chromosomes JOB: Information center🡪 directs most of cell activities  Cytoplasm contains structures called organelles made mostly of water Mitochondrion: has two membranes Used to generate cellular energy (ATP) Inner membrane layer folds inward-Cristae Have their own DNA & Ribosomes Plastids:found in plants Store food and pigments Amyloplast- store starch Leucoplasts store food Chromoplasts store pigments - orange pigment like a carotenoid Chloroplast Chloroplast: Photosynthetic organelle has 2 outer membranes & 1 inner (thylakoid membrane) has interior fluid called Stroma changes energy from sunlight into stored chemical energy Pigment called chlorophyll Game Rules: All team members must have at least one hand on the string form the shape,number or letter of the correct letter first one done and correct wins. The principal role of the cell membrane is to separate and protect the cell from its surroundings. Enable the cell to divide Provide DNA to the cell d) Produce proteins Any cell component that performs specific functions is called: ) an organelle ) a nucleus ) a eukaryote ) a microorganism In which of the following types of cells would you expect to find a large number of mitochondria ? a) bone b) skin c) muscle d) blood A prokaryote has a) a nucleus b) a cell membrane c) membrane bound organelles d) all of the above The structure labeled B is a; 1) centriole 2) protein 3) phospholipids 4) chromosomes Ribosomes found free in the cytoplasm or attached to the ER smallest organelles organize and synthesize proteins Endoplasmic reticulum (ER): -network of channels that transports materials through the inside of the cell -Rough ER: has ribosomes attached Protein synthesis Endoplasmic reticulum (ER): -network of channels that transports materials through the inside of the cell -Smooth ER: no ribosomes attached Site for lipid synthesis and cell detoxification. Golgi apparatus (Golgi Body): -looks like a stack of pancakes -modifies, collects, packages, and distributes molecules made at one location of the cell an used at another Vesicles –small, spherical shaped sacs surrounded by Single membrane and perform various roles. Lysosomes: (the “cleanup” crews) -Bud off from golgi bodies -contain chemicals & enzymes for digesting materials in the cell -digests molecules, old organelles, and foreign substances -Autophagy: digestion of worn-out organelles -Autolysis: destroy old/damaged cells Peroxisomes: found in liver & kidney -neutralize free radicals Vacuoles: -saclike storage structure -stores enzymes and waste products -very large in plants, helps plants grow quickly & supports leaves and flowers -Occupies up to 90% of a plant cell Cytoskeleton: made of variety of filaments & fibers support cell structure & cell movement Types: Microtubules, microfilaments, and intermediate filaments ○ cilia & flagella Centrioles: Only in animal cells cylindrical in shape Involved in cell division: ○ starting place for microtubules Always in pairs Study this cell and be able to recognize the parts. 47 Practice! 48 Do now: pg. 17 Do not give up find the job/description of what is going wrong in the cell and then think about what organelle/part typically does that job correctly. HW: Topic 1 Review Questions from the from page. On a separate sheet of paper or on the computer.  Endosymbiosis Hypothesis Eukaryotic cells evolved from a combination of different prokaryotic cells Symbiosis: a close relationship between two species in which at least one species benefits from the other Mitochondria & Chloroplasts🡪 descendents of ancient prokaryotic cells: -have 2 outer membranes (one from prokaryotic cell that was engulfed and one from the cell that engulfed it) -have their own DNA (which is similar to that of prokaryotes) -reproduce separately from rest of cell -contain ribosomes like those found in prokaryotes The End