Plant Biology Chapter 3 Lecture Outline PDF

Because learning changes everything. ® Chapter 3 Lecture Outline Cells FIFTEENTH EDITION James E. Bidlack, Shelly H. Jansky © 2021 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further di...

Because learning changes everything. ® Chapter 3 Lecture Outline Cells FIFTEENTH EDITION James E. Bidlack, Shelly H. Jansky © 2021 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill.  Outline Introduction to Cells Cells History Modern Microscopes Eukaryotic versus Prokaryotic Cells Cell Structure and Communication Cell Size The Cell Wall Communication between Cells © McGraw Hill 2  Outline: Cell Components Cell Components The Plasma Membrane The Nucleus The Endoplasmic Reticulum Ribosomes Dictyosomes Plastids Mitochondria Microbodies Vacuoles The Cytoskeleton © McGraw Hill 3  Outline: Cellular Reproduction and Higher Plant Cells Versus Animal Cells Cellular Reproduction The Cell Cycle Interphase Mitosis Higher Plant Cells Versus Animal Cells © McGraw Hill 4  Introduction to Cells All living things are are composed of cells. All living things began life as a single cell. Early cells that result from a single cell are similar. Differentiation occurs in structure and function. Some specializations allow transport of food and water. Other specializations modify cells so they can secrete various fluids. Cells have varying life spans. Cells share common features. © McGraw Hill 5  Cells: History 1665 - Cells discovered by Robert Hooke. 1670s - Marcello Malpighi and Nehemiah Grew described single-celled organisms Referred to them as “animacules” 1809 – Jean Baptiste de Lamarck said “No body can have life if its constituent parts are not cellular tissue.” © McGraw Hill © Science & Society Picture Library/ Contributor/Getty Images 6  History 1824 – Rene J.H. Dutrochet concluded that all plant and animal animal and plant tissues are made of cells Reinforced Lamarck’s statement 1831 - Robert Brown discovered the nucleus. Matthias Schleiden discovered the nucleolus shortly after Brown’s discovery. 1838 - Schleiden and Theodor Schwan formulated the Cell Theory Cell Theory states that all living organisms are composed of cells and cells form a unifying structural basis of organization. © McGraw Hill 7  Advances in the Understanding of Cells 1858 - Rudolf Virchow argued there is no spontaneous generation of cells. Louis Pasteur 1862 - experimentally disproved spontaneous generation 1871 - concluded that natural alcoholic fermentation always involves the activity of yeast. 1897 – Eduard Buchner accidentally discovered that fermentation could occur without living yeast cells Extracts from cell contained the necessary enzymes © McGraw Hill 8  Modern Microscopes: Light Microscopes Light Microscopes Increase magnification as light passes through a series of transparent lenses made of glass or calcium fluoride crystals Include compound microscopes and dissecting microscopes, or stereomicroscopes © McGraw Hill 9  Compound Microscopes Light passes through thinly sliced material In general can distinguish organelles 2 micrometers or larger in diameter Can magnify up to 1500x © McGraw Hill © Comstock/Alamy 10  Dissecting Microscopes Also known as stereomicroscopes Allow three-dimensional viewing of opaque objects Can magnify up to 30x © McGraw Hill © Richard Hutchings 11  Electron Microscopes Use a beam of electrons produced when high-voltage electricity is passed through a wire Include transmission and scanning electron microscopes. © McGraw Hill 12  Transmission Electron Microscopes Up to 200,000x magnification, but material must be sliced extremely thin © McGraw Hill Courtesy of JEOL-USA, Inc., Peabody, MA 13  Scanning Electron Microscope Up to 10,000x magnification Surface detail can be observed on thick objects. © McGraw Hill Courtesy of JEOL-USA, Inc., Peabody, MA 14  Scanning Tunneling Microscopes Uses a probe that tunnels electrons upon a sample Produces a map of sample surface Even atoms can become discernible First picture of DNA segment showing helical structure © McGraw Hill 15  Eukaryotic versus Prokaryotic Cells Prokaryotic - Cells lack a nucleus. Bacteria Eukaryotic - Cells contain a nucleus. Unicellular eukaryotes, fungi, plants, and animals Organelles - Membrane-bound bodies found within eukaryotic cells © McGraw Hill 16  Cell Structure and Communication Cell Wall surrounds protoplasm. Protoplasm consists of all living cell components. Bound by plasma membrane Cytoplasm consists of all cellular components between the plasma membrane and the nucleus. Cytosol - Fluid within cytoplasm containing organelles Organelles - Persistent structures of various shapes and sizes with specialized functions Most, but not all, are bound by membranes. © McGraw Hill 17  Anatomy of a Young Plant Cell (a) Access the text alternative for slide images. © McGraw Hill 18  A Young Plant Cell (b) Access the text alternative for slide images. © McGraw Hill © Biophoto Associates/Science Source 19  Cell Size Cells of higher plants generally vary in length between 10 and 100 micrometers. Increase in surface area of a spherical cell is equal to the square of its increase in diameter, but its increase in volume is equal to the cube of its increase in diameter. Smaller cells have relatively large surface to volume ratios enabling faster and more efficient cellular communication. © McGraw Hill 20  Scanning Electron Micrograph of a Plant Cell © McGraw Hill © DR DAVID FURNESS, KEELE UNIVERSITY/Getty Images 21  Cell Wall Main structural component of cell walls is cellulose (long chains of glucose monomers). Also contain matrix of: Hemicellulose - Holds cellulose fibrils together Pectin - Gives stiffness (like in fruit jellies) Glycoproteins - Proteins with associated sugars Middle lamella first produced when new cell walls are formed. Shared by two adjacent cells © McGraw Hill 22  Cellulose Microfibrils Access the text alternative for slide images. © McGraw Hill © BioPhoto Associates/Photo Researchers 23  Primary Cell Wall Flexible primary walls are laid down on either side of the middle lamella. Consists of a fine network of cellulose, hemicellulose, pectin, and glycoproteins © McGraw Hill 24  Secondary Walls Secondary walls produced inside primary walls. Derived from primary walls by thickening and inclusion of lignin Cellulose microfibrils embedded in lignin for strength. Access the text alternative for slide images. © McGraw Hill Source: Reproduced by permission of the Oklahoma Academy of Science. 25  Communication Between Cells Fluids and dissolved substances can pass through primary walls of adjacent cells via plasmodesmata. Plasmodesmata are cytoplasmic strands that extend between cells through minute openings. Access the text alternative for slide images. © McGraw Hill (a) © Biophoto Associates/Science Source 26  Plasma Membrane The semipermeable outer boundary of the living part of the cell. Regulates movement of substances into and out of cell Composed of phospholipid bilayer, with proteins interspersed throughout Fluid mosaic model – This is a dynamic structure Access the text alternative for slide images. © McGraw Hill 27  Nucleus Nucleus: control center of cell Contains DNA. Sends coded messages from DNA to be used in other parts of the cell Bound by two membranes, which together constitute the nuclear envelope Structurally complex pores occupy up to one-third of the total surface area. Permit only certain kinds of molecules to pass between nucleus and cytoplasm © McGraw Hill 28  Components of the Nucleus Contains fluid nucleoplasm which provides a medium for Nucleoli - Composed primarily of RNA Chromatin Strands Composed of DNA and proteins Coil and become chromosomes Access the text alternative for slide images. © McGraw Hill Courtesy of Ron Milligan 29  Endoplasmic Reticulum Endoplasmic reticulum is enclosed space consisting of a network of flattened sacs and tubes forming channels throughout the cytoplasm. Facilitates cellular communication and channeling of materials Synthesizes membranes for other organelles and modifies proteins © McGraw Hill 30  Rough ER and Smooth ER Rough ER - Ribosomes distributed on outer surface of ER. Associated with protein synthesis and storage Smooth ER - Devoid of ribosomes and associated with lipid secretion Access the text alternative for slide images. © McGraw Hill © Dr Jeremy Burgess/Science Source 31  Ribosomes Ribosomes - consist of two subunits that are composed of RNA and proteins Link amino acids to construct complex proteins Subunits assembled in nucleolus. May occur on outside of rough ER, or in cytoplasm, chloroplasts or other organelles No bounding membranes © McGraw Hill 32  Dictyosomes Dictyosomes (Golgi bodies in animals) - Stacks of flattened discs or vesicles Access the text alternative for slide images. © McGraw Hill Courtesy of John Z. Kiss 33  Function of Dictyosomes To modify carbohydrates attached to proteins that are synthesized and packaged in the ER. To assemble polysaccharides and collect them in small vesicles. Vesicles pinched off from margins of dictyosomes. Vesicles migrate to plasma membrane, fuse with it, and secrete contents to the outside of cell. Contents may include cell wall polysaccharides, floral nectars, and essential oils in herbs. © McGraw Hill 34  Plastids Chloroplasts are the most conspicuous plastids. Bound by double membrane and contain: Grana made up of thylakoids Thylakoid membranes contain chlorophyll. First steps of photosynthesis occur in thylakoid membranes. Stroma - Matrix of enzymes involved in photosynthesis Small circular DNA molecule Encodes for production of certain proteins for photosynthesis © McGraw Hill 35  The Chloroplast Access the text alternative for slide images. © McGraw Hill (a) © DR KARI LOUNATMAA/Getty Images; (c) © Biology Pics/Science Source 36  Other Plastids Other types of plastids include: Chromoplasts Synthesize and accumulate carotenoids (yellow, orange, red) Leucoplasts Colorless May synthesize starches (amyloplasts) Or oils (elaioplasts) All types of plastids develop from proplastids © McGraw Hill © James E. Bidlack 37  Mitochondria Mitochondria release energy produced from cellular respiration. Bound by two membranes Inward membrane forms numerous folds = cristae. Increase surface area available to enzymes in matrix Matrix also includes DNA and RNA. Access the text alternative for slide images. © McGraw Hill 38  Microbodies Microbodies are small, spherical bodies distributed throughout the cytoplasm that contain specialized enzymes. Bound by a single membrane Peroxisomes - Serve in photorespiration Glyoxisomes - Aid in conversion of fat to carbohydrates © McGraw Hill 39  Vacuoles In mature cells, 90% of volume may be taken up by central vacuoles. Bounded by vacuolar membranes, tonoplasts Filled with watery fluid called cell- sap Contains dissolved substances, such as salts, sugars, organic acids and small proteins Also frequently contains water-soluble pigments called anthocyanins (red, blue, purple) Functions: maintenance of cell pressure and pH, storage of numerous cell metabolites and waste products. Inside the vacuole is a watery fluid called cell sap, which is slightly to moderately acidic. © McGraw Hill 40  Root Cap with Vacuole Access the text alternative for slide images. © McGraw Hill Courtesy of John Z. Kiss 41  The Cytoskeleton Cytoskeleton - Involved in movement within cell and in cell’s architecture Network of microtubules and microfilaments Microtubules: Control addition of cellulose to cell wall Involved in movement of flagella and cilia Found in fibers of spindles and phragmoplasts in dividing cells Are thin, hollow, tubelike and composed of tubulins (proteins) Microfilaments - Role in cytoplasmic streaming © McGraw Hill 42  Plant Cell Wall and Microtubules © McGraw Hill Courtesy of John Z. Kiss 43  Cellular Reproduction Cell cycle - Orderly series of events when cells divide Divided into interphase and mitosis Interphase Occupies up to 90% of cell cycle Period when cells are not dividing G1 - Cell increases in size. S - DNA replication takes place. G2 - Mitochondria and other organelles divide, and microtubules are produced. Access the text alternative for slide images. © McGraw Hill 44  Mitosis Mitosis refers to the process of cellular division. Produces two daughter cells with equal amounts of DNA and other substances duplicated during interphase Each daughter cell is an exact copy of the parent cell. Mitosis occurs in meristems. Although mitosis is a continuous process, it is divided into 4 phases: prophase, metaphase, anaphase and telophase. © McGraw Hill 45  Chromosomes in Prophase Chromosomes condense by coiling and tightening to become shorter and thicker. Chromosomes made of two identical chromatids held together by centromeres. Kinetochore (protein complex) is located on the outer surface of each centromere. © McGraw Hill 46  Prophase Spindle fibers (microtubules) become attached to the kinetochore and anchored to two poles of the cell. (a) Nuclear envelope dissociates Nucleolus disintegrates Access the text alternative for slide images. © McGraw Hill © Kingsley Stern 47  Metaphase Chromosomes align between the poles around the circumference of the spindle at the cell’s equator. Spindle fibers (b) collectively referred to as the spindle. At the end of metaphase, centromeres holding each sister chromatid separate lengthwise. Access the text alternative for slide images. © McGraw Hill © Kingsley Stern 48  Anaphase Sister chromatids separate in unison and are pulled to opposite poles, with centromeres leading the way. Spindle fibers gradually shorten as material is (c) continuously removed from the polar ends. Chromatids after separation are called daughter chromosomes. Access the text alternative for slide images. © McGraw Hill © Kingsley Stern 49  Telophase Each group of daughter chromosomes become surrounded by a nuclear envelope. Daughter chromosomes become (d) longer and thinner and eventually, indistinguishable. Nucleoli reappear. Spindle fibers disintegrate. Access the text alternative for slide images. © McGraw Hill © Kingsley Stern 50  Cell Plate Formation Phragmoplast develops between daughter cell nuclei. Phragmoplast is a complex of microtubules and ER. Microtubules trap dictyosome-derived vesicles. Vesicles fuse to form cell plate. Cell plate grows outward toward mother cell walls. Cell plate formation Access the text alternative for slide images. © McGraw Hill 51  Higher Plant Cells Versus Animal Cells Plants: Cell walls Cell plate and plasmodesmata Plastids and vacuoles Animals: Internal or external skeletons; no cell walls Plasma membrane called cell membrane. Divide by pinching in two; no cell plate nor plasmodesmata Centrioles present during cell division. No plastids nor vacuoles © McGraw Hill 52  End of Main Content Because learning changes everything. ® www.mheducation.com © 2021 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill.