Introduction_to_living_cells_2023.pptx

Introduction to the Living Cell Axel Nohturfft, Ph.D. 29. September 2023 Further reading & image credits Note references at bottom of figures Learning topics Definition of a cell History of the development of cell theory Shapes and sizes Universal Features of Cells on Earth: Plasma membrane Gen...

Introduction to the Living Cell Axel Nohturfft, Ph.D. 29. September 2023 Further reading & image credits Note references at bottom of figures Learning topics Definition of a cell History of the development of cell theory Shapes and sizes Universal Features of Cells on Earth: Plasma membrane Genetic information stored as DNA Proteins synthesized on ribosomes using RNA as template Evolution Organelles of eukaryotic cells Metabolism Life as a ‘pattern in flux’ Cells are the fundamental unit of all living things on earth. They take nutrients and free energy from their surroundings and make copies of themselves. Robert Hooke (1665) Micrographia Antonie van Leeuwenhoek (1632-1723) Flora Lichtman and Sharon Shattuck. “Animated Life: Seeing the Invisible’. New York Times. September 15, 2014 http://www.nytimes.com/2014/09/16/opinion/animated-life-seeing-the-invisible.html Theodor Schwann Matthias Jakob Schleiden "All living things are composed of cells and cell products" Cells are created through division of pre“Omnis Cellula e Cellula” existing cells (Virchow) Barthélémy du Mortier (1797-1878) How big are cells? Small cell: Mycoplasma genitalium (0.3 µm, 10-14 gram) How big are cells? Big cell: Ostrich egg (20 cm, 2 kg) What do cells look like? Fancy cell: diatom (~ 100µm) Campylodiscus sp. What do cells look like? Quiz ! Universal Features of Cells on Earth The three major domains of the Evolution from a common living world ancestor Taxonomy: “academic discipline of defining groups of biological organisms on the basis of shared characteristics” Phylogenetics: “study of evolutionary relationships among groups of organisms” Universal Features of Cells on Earth All cells are surrounded by a plasma membrane Universal Features of Cells on Earth Cells exchange molecules with their surroundings Universal Features of Cells on Earth Cells communicate Universal Features of Cells on Earth All cells store their hereditary information as DNA Universal Features of Cells on Earth The DNA fragment corresponding to one protein is one gene Universal Features of Cells on Earth Cells translate RNA into protein in the same way Compartmentalization of eukaryotic cells Universal Features of Cells on Earth Cells are made from a few simple building blocks Universal Features of Cells on Earth Cells are made from a few simple building blocks Universal Features of Cells on Earth Cells are made from a few simple building blocks Universal Features of Cells on Earth Life is a “pattern in flux” Rudolf Schoenheimer (1898-1941) “[…] some results of modern biochemistry […] suggest that all constituents of living matter, whether functional or structural, of simple or complex constitution, are in a steady state of rapid flux.” Schoenheimer, R. (1942) Cellular dynamics Cell Picture Show Cells divide ... ... and they die Life is a pattern in flux Replacement of Water Molecules in a 70-kg Human Body Protein Turnover in Human Tissues 98% of the human body is replaced in one year Based on data from: Garlick, PJ et al. Am J Physiol. 1994 Mar;266(3 Pt 1):E287-97. Universal Features of Cells on Earth Homeostasis ! Homeostasis: “The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.” Universal Features of Cells on Earth Homeostasis ! Homeostasis: “The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.” Homeostatic mechanism: Negative feedback control Levels of Homeostasis Chemical. Molecules in cells or blood Discipline: biochemistry Cellular. Maintenance of subcellular structures; proper distribution of organelle -specific proteins, lipids etc. Discipline: cell biology Systemic. Blood pressure, water balance, food intake, body temperature and energy storage etc. Discipline: physiology Populations. Example: changes in predator and prey populations. Biosphere. Global cycles between atmosphere, oceans, rocks, and living organisms are considered as one interrelated system (“Gaia Theory”). Discipline: geophysiology Questions ? References + Further Reading • Alberts et al. (2008) Molecular Biology of the Cell. 5th edition. Garland. • Nelson & Cox (2008) Lehninger - Principles of Biochemistry. 5th edition. Freeman. • Encyclopedia Britannica online. www.britannica.com • Schoenheimer, R. (1942). The dynamic state of the body constituents, Vol 3, 3 edn (New York, Hafner Pubishing Company). p.3 • http://www.cell.com/cell_picture_show-cellcycle