BIOL0011 Lecture 1 Cell Theory, Types PDF

07/09/2016...

07/09/2016 Cell Theory & Types – Outline & Objectives Outline  Cell Theory BIOL0011 Lecture 1  Generalized Cell structure: Prokaryote and Eukaryote Cellular Basis of Life: Objectives – On successful learning of this topic you Cell theory will be able to: 1. State the tenets of the Cell Theory Cell structure 2. Describe/ distinguish between generalized prokaryote and eukaryote cell. 3. Distinguish plant and animal cells 9/7/2016 BIOL0011 2015‐16 1 2015 BIOL0011 2 Seeing cells Cell Theory (Unifying concept in biology) Microscope invented 1600’s Things invisible to naked eye discovered 1. All organisms are composed of one or more cells. Robert Hooke (natural philosopher) First saw cork cells, named them cellulae 1665 2. The cell is the basic organizational unit of life Anton Van Leeuwenhoek (smallest unit to give rise to new life and (microbiologist) 1667 Observed organisms in pond water. sustain life). Matthias Schleiden (botanist) Concluded that all plants and animals are & Theodor Schwann (zoologist), 1800’s composed of cells. Schawnn proposed the first two tenets of the cell theory 3. All cells arise from pre-existing cells by the process of division. Rudolf Virchow (physician) Proposed a third tenet) in response to the 1855 question where do cells come from? Memorize the statements. Quiz each other. Think, pair and share thoughts on the theory with neighbour 2015 BIOL0011 3 2015 BIOL0011 4 Levels of organization in organisms Features of living organisms 1. Composed of cells (membrane, cytoplasm, genetic material, ribosomes; other organelles & structures which vary with the type of cell) 2. Grow and develop (size, biomass, # of cells, differentiate) Semester 1 6 3. Regulate their own metabolic processes (maintain homeostasis). Respire to produce energy. 4. Respond to stimuli (light, temp, sound, pressure, Semester 2 chemicals) by movement 5. Reproduce (sexual/asexual) 6. Adapt (structurally, physiologically, behaviourally) to environmental change (evolve) Individual writing: Structure 7. Organized in levels (eg. chemical, cell, tissue, organ, organ definition “A cell is ….” right of theatre systems) Individual writing: Function http://mwsu‐bio101.ning.com definition “A cell does ….” 5 left of theatre Share with class 1  07/09/2016 Cells are the basic units of life Structure: all cells have these basic components: Membrane plasma membrane surrounds cytoplasm Life processes performed by cells: keeps cell separated from environment, while feed allowing exchange of materials. respire Genetic material excrete Complex processes allows reproduction of cell; continuation of life performed by organelles. metabolize Cytoplasm containing organelles osmoregulate Next lecture cytoplasm = cytosol and organelles aqueous site of metabolic reactions facilitating life communicate distinct part of a cell which has a particular structure and function reproduce Ribosomes 8 site of protein production Basic vs feature discussion Structure vs function discussion 9/7/2016 BIOL0011 2015‐16 7 2015 BIOL0011 Cell structure Generalized prokaryotic (bacterial) cell Cells vary in size vary in shape are either prokaryotic or eukaryotic with regards to basic structure. have internal components (types, size) depending on their function are in many cases, specialized for a particular function (e.g., nerve cells, epithelial cells, erythrocytes, parenchyma, sclerenchyma, collenchyma, ova, sperm, generative cell). 2015 BIOL0011 9 2015 BIOL0011 10 Pro = primitive karyon = nucleus CELLS Eu = true karyon = nucleus Generalized eukaryotic (plant & animal) cell Prokaryotic Cells Eukaryotic Cells simplest cellular organization may be very complex no membrane‐bound organelles contains membrane‐bound organelles [Golgi body; endoplasmic reticulum; mitochondria, nucleus] no organized nucleus; genetic well developed nucleus which material free houses the genetic material 70s ribosomes 80S ribosomes small; 1 small Shape rigid, rectangular flexible, round Lysosomes absent present absent except in some Centrioles present Nucleus typically near the edge central lower plants Golgi Bodies simple elaborate Cytokinesis cell plate contractile ring Endoplasmic continuously elongate stops at present present Growth & differentiate from maturation, Reticulum Ribosomes present present apical meristem replaced. Mitochondria present present Storage starch glycogen Flagella usually absent may be present Nutrition autotrophic heterotrophic Cilia usually absent may be present Write down your statement of misunderstanding. “I want to know…..” “It is unclear to me….” Remember: cells vary 9/7/2016 13 9/7/2016 BIOL0011 2015‐16 14 BIOL0011 2015‐16 Log onto OurVLE to answer Which organelle would be found in a prokaryotic cell? a. Nucleus b. Golgi body c. Ribosome d. Mitochondria 9/7/2016 BIOL0011 2015‐16 15 3