L-5 Fundamental unit of life.pptx
- 1. BIOLOGY Chapter- 5 Fundamental of life Prerna Johari
- 2. TOPIC CELLS: THE BASIC UNIT OF LIFE
- 3. what is a cell ? Cell is the basic unit of life. All organisms are composed of cell Some organisms are unicellular .eg: bacteria And while some are multicellular . eg: human Cell is the fundamental structural and functional unit of all living organisms. The study of cell is known as cell biology or cytology. It represents a distinct branch of biological sciences which studies cell is referred to a Cell Biology.
- 4. Organisms
- 5. The Discovery of the Cell Robert Hooke-1665 Robert Hooke – first tosee and identify cork “cells.” Coined the word “cell”. Looked at cork cells.
- 6. 1. All living organisms are made of cells. 2. Cells are the basic structural and functional unit of all living organisms. 3. New cells arise from preexisting cells.
- 7. Historyof cell study Robert hooke-1665 Coined the word “cell”. Looked at cork cells. Robert brown-1831 Discovered the “nucleus”. TheodorSchwann- 1838 Cells are unit of biological structures. Mattias Schleiden-1850 Cell are the fundamental basis of life. Virchow-1858 All cells come from cells.
- 8. What is cell made up of ? The cell is filled with a semi-fluid matrix called cytoplasm or protoplasm which occupies the major volume of cell. The cytoplasm is the main site of cellular activities in both plant and animal cells. Various chemical reactions take place in the cytoplasm to keep the cell in the ‘living state’. . Cell is the basic structural and functional unit of living organisms. A cell is made up of three main components- 1) Plasma membrane or cell membrane 2) Nucleus 3) Cytoplasm .
- 9. Define cell ? A cell is a mass of cytoplasm or protoplasm having a dense membrane bound nucleus present inside it. This nucleus contains the chromosomes which in turn contain the genetic material in form of DNA.
- 11. Types of cells Types of cells- Prokaryotic cell- The cell which lacks a well-organized or well – defined nucleus and other membrane-bound organelles is known as prokaryotic cell. The organisms which are composed of prokaryotic cells are commonly called as prokaryotes. For example- Bacteria, mycoplasma, PPLO, etc. Eukaryotic cell- The cell which possesses a well-organized nucleus and other membrane-bound organelles is known as eukaryotic cell. The organisms which are composed of eukaryotic cells are commonly called as eukaryotes. For example- protists, fungi, plant and animal cells.
- 13. All eukaryotic cells are not identical. Plant and animal cells are different. A plant cell contains a cell wall outside the cell membrane. An animal cell has cell membrane as the outermost membrane of a cell. Plant cell possess cell walls, plastids, and a large central vacuole. While, animal cells lacks cell wall, central vacuole and plastids.
- 14. Shape of cells- Theshapeandsize ofcellsarerelatedto thespecificfunction theyperform. 1.Smooth Muscle cell. 2. Epithelial cells 3. Nerve cell. 4. Fat cell 5. RBCs. 7 . Spirogyra. 8.Sperm and Ovum. 9.Amoeba. 10.Bacteria.
- 15. Plasma membrane or Cell membrane Plasma membrane is the outermost covering of the cell that separates the contents of the cell from its environment. It is found in all cells. Plasma membrane is made up of two important biomolecules- Lipids and proteins.
- 16. Functions of Plasma membrane Plasma membrane performs various important functions in the cell. It is a selectively permeable membrane that allows or permit the entry and exit of some materials in and out of the cell. It also acts as a barrier and thus prevents the movement of some other materials. It provides support and protection to the cell. Plasma membrane is flexible in nature.The flexibility of the plasma membrane also help the cell to engulf in food and other materials from its external environment. Such process are called endocytosis. Amoeba acquires its food through such processes.
- 17. Movement of substances across the cell The movement of substances takes place into and out of the cell. Plasma membrane plays an important role in movement of substances into and out of the cell. Process/ Methods- Diffusion -movementof particles from a region of high concentration to low concentration. Osmosis-the diffusion of water through a selectively permeable membrane.
- 18. Diffusion Diffusion – movementof particles from an region of highconcentration to low concentration. Example- some substances like carbon dioxide or oxygen can move across the cell membrane by a process called diffusion. Thus, diffusion plays an important role in gaseous exchange between cells as well as the cell and its external environment.
- 19. Osmosis Osmosis – the diffusion of water through a selectively permeable membrane. Water also follows the law of diffusion. The movement of water molecules through takes place through selectively permeable membrane is called osmosis. Osmosis is the movement of water or water molecules from a region of high water concentration to region of low water concentration. The movement of water across the plasma membrane is also affected by the amount of solute or substance dissolved in water. Water will move in/out of a cell to equalize the concentrations.
- 21. Types of solutions Solvent +Solute = There are three types of solutions- Hypotonic Isotonic Hypertonic
- 25. What will happen if we put an animal cell or a plant cell into a solution of sugar or salt in water ?
- 27. CellWall
- 28. CELLWALL 1. a non living rigid structure . 2. Forms an outer covering for plasma membrane inplant cells. FUNCTION: 1) Determining Cell Shape. 2) Strength. 3) Controlling Turgor Pressure. 4) Passage of Substances. 5) Protection.
- 29. Cell Organelles Eukaryotic cell possess well-developed membrane bound little structures within their cytoplasm. These membrane bound little structures are called Cell Organelles. Nucleus Endoplasmic Reticulum (ER) Golgi apparatus or Golgi complex Lysosome Mitochondria Plastids Vacuoles
- 31. Nucleus Every eukaryotic cell has a well-defined nucleus in their cytoplasm. Robert Brown for the first time in 1833 discovered a prominent body within the cell and termed it as “nucleus”. The nucleus is a double wall structure that is remain two surrounded by two nuclear membranes- outer nuclear membrane and inner nuclear membrane. The nuclear membrane has pores called nuclear pores which allow the transfer of substances or materials from inside the nucleus to its outside in the cytoplasm. The nucleus contains genetic material in the form of DNA. Genes are located on DNA. Chromatin material – chromosomes
- 32. Ultrastructure of the Nucleus : The nucleus contains three important parts, namely, i) nuclear membrane or nuclear envelope, ii) nucleolus and iii) chromatin material or chromosomes.
- 33. Functions of Nucleus Nucleus play an important role in cell. It is controlling center of the cell. The nucleus contains genetic material in the form of DNA. Genes are located on DNA. Chromatin material – chromosomes – hereditary vehicles which passes genetic information from parents to their offspring. It also plays a central role in cellular reproduction.
- 34. Endoplasmic Reticulum • Discovered by Porter and Thompson. • I t is a complex membrane lined network of flattened sac, tubles etc.. • runs through out cytoplasm of eukaryotic cells. • Consists of 30-40% of total endomembrane system. • Divides the intercellular space into components-Luminal and extraluminal FUNCTIONS: 1. Mechanical support 2. Conduction of information 3. Intercellular transport 4. Localization of enzyme 5. Large surface area.
- 36. • Types of Endoplasmic reticulum- i) Rough endoplasmic reticulum (RER). ii) Smooth endoplasmic reticulum (SER). FUNCTION OF RER: 1. Protein for transport 2. Protein processing FUNCTION OF SER: 1. Storage. 2. Glycogenolysis. 3. Removal of toxic materials.
- 37. Endomembranesystem contains only those organelles whose functions are coordinated. Itconsistsof: Endoplasmic reticulum(ER) Golgi complex lysosomes Vacuoles
- 38. Golgi Apparatus
- 39. GOLGIAPPARATUS • Is a cytoplasmic organelle of smooth membrane sac. • Dicovered by Camillo golgi, • Found in eukaryotic cells (except mammalian erythrocytes) • Occur between nucleus and exposed cell membrane. • Surrounded by zone of cytoplasm which is devioded of ribosomes, mitochondria, etc... FUNCTIONS: Package materials. And important for formation of glycoprotein.
- 40. LYSOSOMES LYSOSOMES • Membrane bound vesicular structure • Formed by packaging of golgi appartus. • Very rich in hydrolytic enzymes. • Enzymes are capable for digesting carbohydrate, protein, lipid, mucleic acid. • Polpularly cal l ed as “suicidalbags”,
- 41. MITOCHONDRIA • Thesearedouble –membrane bound, sausage – shaped semi-autonomous organelles. • The electron micrograph shows that the boundarymembranes are separated by a fluid filled space called outer compartment. • The outer membrane is smooth but the inner smooth projects in the form of many folds called cristae into the matrix. • The matrix is rich in enzymes, a circu lar DNA • molecule and many small ribosomes. • The inner membrane and the cristae bear a number of particles, which havea spherical head– piece (F1 subunit) and a stalk (F0 subunit) that is embedded in the lipid of the membrane. • The F0 – F1combination functions as ATP synthetase. • The main function of mitochondria is aerobic respiration and ATP synthesis. • “Power houses of cell”
- 42. Plastids PLASTIDS • Plastids are double – membrane bound organelles of different shapes, that are found only in plant cells and contain pigments and storage products. Theycontainpigments,impartingcolorsand storageproducts.
- 43. TypesofPlastids- • Thesearethreetypes of p lastids, depending on their colour and functions. I) CHROMOPLASTS • These are the coloured plastids containing mainly the yellow, red and orangepigments (carotene and xanthophylls). (II) CHLOROPLASTS • Thesearethe green plastids containing mainly chlorophylls and very little of carotene and xanthophylls. • Chloroplasts may be lens – shaped, oval,spherical , discoid, ribbon-like or cup –shaped • Each chloroplast has a double membrane covering, enclosing the colourless matrix called stroma.
- 44. (II) LEUCOPLASTS Colorlessplastids V ariousshapesandsizes w ithstorednutrients LEUCOPLASTcanbedivided into3:- Amy loplasts– store carbohydrates Elaioplasts– storeoils andfats. Aleuroplasts– store proteins.
- 46. Plastids Plastidscanbeclassifiedinto: CHLOROPLAST • Contains chlorophylland carotenoid pigments. • F oundmainlyin mesophyllof leaves . • T hesearelens shaped,oval shaped,spherical, discoidor even ribbon-like organelles. CHROMOPLAST • Containsfatsoluble carotenoid pigmentslike carotene, xanthophylls and othersarepresent. • F oundinyellow , orange,red. LEUCOPLAST • Colorlessplastids • V ariousshapesand sizes w ithstored nutrients • LEUCOPLASTcanbe divided • into3:- • Amyloplasts– store carbohydrates • Elaioplasts– storeoils and fats. • Aleuroplasts– store proteins.
- 47. Vacuoles In amoeba, membrane-bound sacs called contractile vacuole and in protista food vacuole VACUOLES: • In plant cells, Membrane bound space found In cytoplasm. • Bounded by single membranecalled tonoplast,
- 48. VACUOLE VACUOLES: • In amoeba, called contractile vacuole and in proista food vacuole
- 50. ANIMAL CELL
- 51. PLANTCELL
- 52. Reference list • Robayda, A. (2013). cell the unit of life. Available: http://www.slideshare.net/AishaRobayda/cell-the-unit-of-life-1?qid=12bc18e8-e13c- 4232-9b02-cf1652411b05&v=qf1&b=&from_search=3 (Accessed 07 march 2014) • ittah,E. (2013). Cell- The basic Structure of life. Available: http://www.slideshare.net/ericittah/eric-ittah-canada-eric- ittah?qid=12bc18e8-e13c-4232-9b02-cf1652411b05&v=qf1&b=&from_search=5 (accessed 07 march 2014) • Baiju, V. (2011). Cell The unit of life. Available: http://www.slideshare.net/VigneshBaiju/cell-the-unit-of-life- 10230437?qid=12bc18e8-e13c-4232-9b02- cf1652411b05&v=qf1&b=&from_search=8 (accessed 07 march 2014)