Presentation on theme: "Introduction to cell Dr. Ajith Sominanda (MBBS,MPhil,PhD) Senior Lecturer Department of Anatomy Faculty of Medicine Peradeniya."— Presentation transcript:
Introduction to cell Dr. Ajith Sominanda (MBBS,MPhil,PhD) Senior Lecturer Department of Anatomy Faculty of Medicine Peradeniya
Outline of the lecture 1. Origin of the life 2. Characteristic features of living things 3. The unit of the life: the cell 4. Components of the cell and their functions 5. Beyond the cell
1.Origin of the life
Origin of the universe occurred 15 billion years ago
Prebiotic chemistry and origin of the life ‘’Life could have arisen through chemistry’’ - Charlse Darwin (probably)
Miller-Urey’s experiments on pre-biotic chemistry in 1953
Change of organic chemicals into ‘life’ substance Chemically reducing conditions can form amino acids Pre-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.
Archean chemistry of prebiotic era
Life 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.
The earlier most evidence of life on earth 3.5 billion years back Fossilized imprints of micro-organisms which resemble modern blue-green algae (cynobacteria)
The scientific definition An organized thing or a system capable of self 1.Growth 2.Synthesis and degradation of materials by utilizing or releasing energy-Metabolism 3.Keep a balance of the activities and conditions - Homeostasis 4.Response to the environmental stimuli 5.Reproduction
Antony van Leeuwenhoek (1632-1723) and the micro world
The visibility & the expansion of our understanding
Electron microscope & Ultra structure Hydrogen atom 0.1nm = 1 Å
The unit of the life: Cell
Differences between pro and eu Karyotic cells ?
Home work Find a text book in histology, i.e. Basic Histology by Carlos Junqueira Read the first chapters on cytoplasm and nucleus and then list the structural features and functions of components of the cell