Presentation on theme: "Introduction to cell Dr. Ajith Sominanda (MBBS,MPhil,PhD)"— Presentation transcript:
1Introduction to cell Dr. Ajith Sominanda (MBBS,MPhil,PhD) Senior LecturerDepartment of AnatomyFaculty of MedicinePeradeniya
2Characteristic features of living things Outline of the lectureOrigin of the lifeCharacteristic features of living thingsThe unit of the life: the cellComponents of the cell and their functionsBeyond the cellmodern evolutionary movement, which is now thought to have occurred in six phases: (1) Cosmic Evolution (the origin of space, time, matter and energy from nothing); (2) Chemical Evolution (the development of the higher elements from hydrogen); (3) Stellar and Planetary Evolution (the origin of stars and planets); (4) Organic Evolution (the origin of organic life from a rock); (5) Macro Evolution (the origin of major kinds); and (6) Micro Evolution (the variation within the kinds).
8Change of organic chemicals into ‘life’ substance Chemically reducing conditions can form amino acidsPre-biotic earth was low in oxygen (reducing atmosphere) and therefore amino acids could have formed with lightning or in the sea bed hydrothermal vents etc.
10Life could have come from outside rather than the chemical evolution on earth Murchison meteorite, which fell in Australia. Amino acids found in the meteorite were apparently present in it when it fell.
11The earlier most evidence of life on earth 3.5 billion years back Fossilized imprints of micro-organisms which resemble modern blue-green algae (cynobacteria)
12The scientific definition An organized thing or a system capable of selfGrowthSynthesis and degradation of materials by utilizing or releasing energy-MetabolismKeep a balance of the activities and conditions - HomeostasisResponse to the environmental stimuliReproduction
13Antony van Leeuwenhoek (1632-1723) and the micro world
14The visibility & the expansion of our understanding
15Electron microscope & Ultra structure Hydrogen atom 0.1nm = 1Å
35Home workFind a text book in histology, i.e. Basic Histology by Carlos JunqueiraRead the first chapters on cytoplasm and nucleus and then list the structural features and functions of components of the cell