1 Lectures on Plant Physiology Prepared by Prof Mohammed Naguib Abdel-Ghany Haseneen Professor of...
Transcript of 1 Lectures on Plant Physiology Prepared by Prof Mohammed Naguib Abdel-Ghany Haseneen Professor of...
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Lectures on Plant Physiology
Prepared by
Prof Mohammed Naguib Abdel-Ghany Haseneen
Professor of Plant physiology For
Pre-Dental Students
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Contents
• Plant Cell– Plant Cell structure and function
• Different Bio-Physico-Chemical Phenomena– Colloids– Diffusion– Osmosis– Imbibitions
• The Enzymes– Structure– Mode of action– Inhibitors– Factors affecting enzymatic activity
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Cont.
• Metabolism• Respiration
– Glycolysis, TAC, Fermentation– Factors affecting rate of respiration
• Amino acid and protein metabolism• Biotechnology• -What is biotechnology?• Biotechnology benefit
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1- Plant Cell (Structure and Function)1- Plant Cell (Structure and Function)
• Cells are the basic unit of life.• Cells carryout all the necessary functions for
life such as: reproduction, taking in nutrients and excreting wastes.
• Cells are made up of chemicals and molecules. Human cells contain mostly water.
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The CellThe Cell
• Cells are classified as prokaryotic and eukaryotic.
• Prokaryotic cells lack a well-defined nucleus and many organelles. Bacteria are prokaryotic cells.
• Eukaryotic cells include the protists, fungi, plant and animal cells. We will study these cells during this lab.
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The CellThe Cell
• Animal Cells• Have centrioles• Store glucose as
glycogen• Do not have a cell wall• Contain mitochondria
• Plant Cells• Lack centrioles• Store glucose as
cellulose or starch• Have a cell wall• Have large vacuoles• Contain chloroplasts
as well as mitochondria
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The CellThe Cell
• Animal Cell• Click on the cell to
study it in more detail
• Plant Cell• Click on the cell to
study it in more detail
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Animal CellClick on each organelle to learn its function. When you have finished click on the arrow button to study the plant cell.
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Plant CellClick on each organelle to study its function. When you have finished click here to study the animal cell or here to continue this lab.
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- Supports cells & plant- Controls cell growth & shape
Cell is a unit or module of plant organizationCell is a unit or module of plant organization
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Cell WallCell Wall
• Only found in plant cells• Surrounds cell membrane• Composed of lignin and cellulose• Function to strengthen and protect plant cells.
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Cell WallCell Wall
• Structural functions– Provides rigidity to plant– Determines size and shape of cell– Determines size and shape of plant
• Other functions– Absorption– Transport– Secretion– Cell-cell communication
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Structure of cell wallStructure of cell wall
• Cellulose is principal component– Repeated monomers of glucose attached end to end– Bundled into microfibrils– Crystalline properties
• Cellulose matrix is embedded in matrix of noncellulosic molecules– Provide cross-links between cellulose microfibrils– Pectins = hydophilic polysaccharides– Glycoproteins- extensins
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Structure of cell wall continuedStructure of cell wall continued
• Primary wall– Formed first while cells growing and dividing– Enriched in pectins and water (to allow expansion)
• Middle lamella– Joins adjacent cells– Mostly pectins
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Cell wall structure continuedCell wall structure continued
• Secondary wall– Not all cells form– Deposited after cell has stopped growing– Inside primary wall– More cellulose– Pectins lacking– Rigid– Formed by cells that provide strength or transport
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Cell walls (yellow) separated by middle lamella (black)
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Middle lamella (black) separates walls from 2 different cells
Cell membrane contacts inner part of wall
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Cellulose is polymer of glucose that aggregates into threads (microfibrils)
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Cellulose Cellulose threadsthreads
are woven in are woven in cell wallcell wall