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Cell biology
- 1. CELL BIOLOGY Presented by:- Janhavi Yashwant Burade Vidyabharti College of Pharmacy , Amravati M.pharm
- 2. Content Introduction Structureof cell and it’s organelles Function of cell and it’s organelles
- 3. Introduction Cell :- Thecell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known organisms. A cell is the smallest unit of life. Cells are often called the "building blocks of life". The study of cells is called cell biology, cellular biology, or cytology. Self replicating structure. First cell were observed and named by Robert Hooke in 1665 from slice of cork. Some organisms consists of a unicellular organism,other are multicellular. Diameter:- 2-120um. There are two type of cell :- prokaryotic cell and eukaryotic cells. A prokaryotic cell is a type of cell that does not have a true nucleus or membrane- bound organelles. Organisms within the domains Bacteria and Archaea are based on the prokaryotic cell, while all other forms of life are eukaryotic.
- 4. Difference Between Prokaryoticand Eukaryotic Cells
- 5. Constituents Different substancesthat make a cell are Collectively called protoplasm. Protoplasm composed by:- Water – 70-80% water is present in cell Carbohydrates Lipids Proteins Electrolytes :- Sodium (Na+), potassium (K+) , magnesium (Mg2+), calcium ( Ca2+), phosphate, chloride (Cl-), and Bicarbonate ( HCO3-)
- 6. Major Structure Presentin a Cell are :- Cell Wall ( absent in animal cell) Cell Membrane Cytoplasm and it’s organelles Nucleus
- 7. Difference between plantcell and animal cell
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- 10. Structure and functionof cell organelles Cell Wall:- Structure :- Non-living and outermost covering of a cell( plants and bacteria) Can be tough,rigid and sometimes flexible Made up of cellulose, hemicellulose and pectin May be thin or thick, multilayered structure Thickness varies from 50-1000 Å Function:- Provides definite shape , strength and rigidity Prevents drying up ( desiccation) of cells Helps in controlling cell expansion Protects cell from external pathogens
- 11. Cell Membrane Structure:- Also called as semipermeable membrane or plasma membrane Extremely delicate, thin, elastic, living and semipermeable membrane Made up of two layers of lipid molecules in which protein molecules are floating Thickness varies from 75-110 Å Can be observed under an electron microscope only Function:- Maintain shape and size of the cell Protects internal contents of the cell Regulates entry and exit of substances in and out of the cell Maintain homeostasis
- 12. Nucleus Structure:- Densespherical body located near the centre of the cell Diameter varies from 10-25um Present in all the cells except red blood cells and sieve tube cells Well developed in plant and animal cell Undeveloped in bacteria and blue green algae (cyanobacteria) Most of the cells are uninucleated ( having only one nucleus) Few types of cells have more than one nucleus (skeletal muscle cells) Nucleus has a double layered covering called nuclear mmberane Nuclear membrane has pores of diameter about 80-100nm Colourless dense sap present inside the nucleus known as nucleoplasm Nucleoplasm contains round shaped nucleoid and network of chromatin fibres Fibres are composed of DNA and protein histone These fibres condensed to form chromosomes during cell division Chromosomes contain stretches of DNA called as genes Genes transfer the hereditary information from one generation to the next
- 14. Function:- Control allthe cell activities like metabolism, protein synthesis, growth and cell division Nucleolus synthesized RNA to constitute ribosomes Store hereditary information in genes
- 15. Cytoplasm Structure:- It isthe fluid content present inside the plasma membrane It contains specialized cell organelles Jelly like material formed by 80% of water Present between the plasma membrane and nucleus Contains a clear liquid protein called cytosol and various particles Particles are proteins, carbohydrates, nucleic acids, lipids and inorganic ions Also contains many organelles with distinct structure and function Some of these organelles are visible only under an electron microscope Granular and dense in animal cell and thin in plant cell Function :- It acts as the store of important chemicals It is a physical basis of all metabolic activities It keeps the cell fully expanded and provide turgidity
- 16. Endoplasmic Reticulum Structure:- Networkof tubular and vesicular structures which are interconnected with one another Some parts are connected to the nuclear membrane while another are connected to the cell membrane Two types :- 1. smooth endoplasmic reticulum( lack of ribosomes),2. Rough endoplasmic reticulum (studded with ribosomes) Function:- Gives internal support to the cytoplasm RER synthesize secretory protein and membrane proteins SER synthesize lipids for cell membrane In liver cells SER detoxify drugs and poison In muscle cells SER store calcium ions
- 17. Ribosomes Structure:- Ribosomes aredense spherical granular particles which move freely in the matrix They are present in cytoplasm as well as inside the nucleus A ribosomes is made numerous proteins and RNA Function:- They play important role in protein synthesis It helps in storage modification and packaging of products in vesicles It is involved in synthesis of lysosomes
- 18. Golgi Body (Golgi Complex ) Structure:- Discovered by Camillo Golgi Formed by stacks of 5-8 membranous sacs Sacs are usually flattened and are called Cisternae Has two ends :- Cis face situated near the endoplasmic reticulum and Trans face situated near the cell membrane Function :- Modifies , sorts and packs material synthesized in the cell Delivers synthesized material to various targets inside the cell and outside the cell Produce vacuoles and secretory vesicles Forms plasma membrane and lysosomes
- 19. Lysosomes Structure :- Small, spherical, single membrane sac Found throughout the cytoplasm Filled with hydrolytic enzymes Occur in most animal cells and in few types of plant cells Function :- Help in digesting of large molecules Protect cell by destroying foreign invader like bacteria and viruses Degradation of worn out organelles In dead cells perform autolysis
- 20. Vacuoles Structure :- Singlemembrane sac filled with liquid or sap ( water , sugar and ions ) In animal cells , vacuoles are temporary, small in size and few in number In plant cells , vacuoles are large and more in number May be contractile on non – contractile Function :- Store various sub including waste products Maintain osmotic pressure of the cell Store food particles in amoeba cells Provide turgidity and rigidity to plant cells
- 21. Mitochondria ( powerhouse of cell ) Structure :- Small , rod shaped organelles bounded by two membrane – inner and outer Outer membrane is smooth and encloses the contents of mitochondria Inner membrane is folded in the form of shelf like inward projection called Christae Inner cavity is filled with matrix which contains many enzymes Contain their own DNA which are responsible for many enzymatic actions Function :- Synthesize energy rich compound ATP ATP molecules provides energy for the vital activities of living cells
- 22. Plastids Plastids consistsof numerous membrane layers embedded in a material called the strome Plastids are of three types :- Chromoplast , Leucoplast , Chloroplast Chromoplast :- They are coloured plastids except green . They are present in flowers to attract insects for pollination . Leucoplast:- They are colourless or white plastids . They store starch , oils and protein granules. Chloroplast :- They are green Coloured plastids which are important for photosynthesis for plants . They contain green colour pigments chlorophyll. They are known as kitchen of cells . Function :- They manufacture food through Photosynthesis They provide colours to fruits and flowers to attract insects for pollination It store starch , oil and protein granules
- 23. Centrosome Structure :- Centrosomeis the membrane bound organelles present near the nucleus Consists of two structure called as centrioles Centrioles are hollow , cylindrical structure made of microtubules Centrioles are arranged at right angles to each other Function :- Form spindle fibres which help in the movement of chromosomes during cell division Help in the formation of cillia and flagella
- 24. Cytoskeleton Structure :- Formedby microtubules and microfilaments Microtubules are hollow tubules made up of protein called tubulin Microfilaments are rod shaped thin filaments made up of protein called actin Function :- Determine the shape of the cell Give structural strength to the cell Responsible for cellular movements
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