Cells PDF

Bas ese hi mehnat karte rho 💙 hero PREPOMETER ko honestly follow kro, message me kitna pdha din bhar mai🌱 9198151228...Study hard, 💪 Maximum revision. Success is waiting for you brother.  The shape and size...

Bas ese hi mehnat karte rho 💙 hero PREPOMETER ko honestly follow kro, message me kitna pdha din bhar mai🌱 9198151228...Study hard, 💪 Maximum revision. Success is waiting for you brother.  The shape and size of cells are related to the specific function they perform. Division of labour is also seen within a cell. Each such cell has got certain specific components within it, known as CELL ORGANELLES. Generally, a cell has plasma membrane, nucleus and cytoplasm. Cell differ greatly in size , shape and activities. Bacteria could be 3 to 5 um Mycoplasma, smallest cells, are in length. ( um – micrometre ) o.3um in length. NO CELL WALL Nerve cells are some of The largest isolated single the longest cells. cell is the egg of an ostrich. Among multicellular organisms, The smallest cell in the human human red blood cells are about body is the sperm (male gamete). 7.0um in diameter.  Diffusion is important for Three kind of medium cells to obtain nutrition :- Hypotonic, from its environment and Hypertonic, Isotonic. exchange gases & water. Cell intakes Unicellular oxygen - cellular freshwater 01 01 organisms and respiration. Cell excreted out most plant cells tend to gain carbon dioxide - 02 02 water through cellular waste. osmosis. DIFFUSION vs OSMOSIS The movement The movement of of substances 03 03 water from High from concentration to High 04 04 Low Concentration Concentration through a to Low semipermeable Solute move from Solvent move from Concentration. membrane. High Concentration to Low Concentration to Low Concentration. High Concentration. ACTIVE TRANSPORT Active transport is an energy dependent PASSIVE TRANSPORT process, in which ATP is utilized. Many molecules are transported across A few ions or molecules are transported the membrane along the concentration across the membrane against their gradient, concentration gradient, From higher to lower concentration. From lower to the higher concentration. Diffusion and Osmosis. Reverse osmosis. e.g., Na+/K+ Pump. OSMOSIS HYPOTONIC HYPERTONIC ISOTONIC The medium surrounding When the medium has a When the medium has the cell has a higher lower concentration of exactly the same water concentration of water water than the cell, concentration as the cell, than the cell. meaning that it is a very there will be no net Cell gains water by concentrated solution, movement of water osmosis as outside the cell will lose water across the cell solution is very dilute. by osmosis. membrane. Cell swells up. Cell shrinks. Cell remains same.  CELL NUCLEUS CELL OR PLASMA MEMBRANE Lorem ipsum dolor sit amet Outermost covering of the CYTOPLASM Nucleus membrane consectetur adipiscing elit,has at sociis senectus ullamcorper morbi cell that separates the pores which facilisi allow curabitur, the fusce scelerisque Cytoplasm is the gel-like contents of the cell from transfer of material from vulputate euismod nulla justo. liquid that fills the inside of a FRESH IDEA its external environment. inside nucleus to outside plasma membrane. cytoplasm. Universal membrane or Protoplasm consists of Selectively permeable. cytoplasm & nucleus, it Nucleus has double contains various proteins, membrane. other essential molecules. Cell membrane is mainly Nucleus plays a central composed of lipids and It consists of the cytosol, role in cellular proteins (phospholipids) organelles, cytoskeleton & reproduction the bilayer also contains inclusion. process by which a cholesterol, carbohydrates. single cell divides and Cytosol: Semi-fluid, jelly-like forms two new cells. The ratio of protein & lipid substance that makes up Contains chromosomes. varies considerably in most of the cytoplasm & different cell types. The nucleus is called as contains water, ions, proteins, lipids, & small the brain of the cell. molecules. Organelles: Structures like Mitochondria, ER, Golgi apparatus, & Ribosomes are suspended in the cytoplasm. Cytoskeleton: A network of protein fibers (microfilaments, Allows or permits the microtubules, and entry and exit of materials intermediate filaments) that In some organisms like in and out of the cell. provide structural support, bacteria, the nuclear motility and maintenance. region of the cell poorly Transfer of gases like defined due to the oxygen and carbon absence of a nuclear dioxide through Diffusion. Inclusions: Temporary membrane. structures like stored nutrients ( Phosphate Such an undefined granules, cyanophycean nuclear region containing granules & glycogen granules), only nucleic acids is called pigments, waste products. a nucleoid. CELL RATIO: Water > Protein > Nucleic acid > Carbohydrates > Lipids > Ions.  CHROMATIN MATERIAL CHROMOSOMES Present inside the Rod shaped structure nucleus. visible only when the cell Visible under microscope is about to divide. during cell division Chromosomes are separated into daughter composed of DNA and cells. protein CENTROSOME Centrosome is an organelle usually containing two cylindrical structures Made up of DNA and called centrioles. Chromosomes contain histone, proteins. information for Present in animal cells. DNA wraps around inheritance of the The centrioles form the features from parents to histone proteins to basal body of cilia or next generation in the form nucleosomes, flagella, and spindle fibres form of DNA (Deoxyribose which are the basic unit that give rise to spindle Nucleic Acid) molecules. of chromatin. apparatus during cell division in animal cells. Chromatin's main function: DNA molecules contain package DNA into a more information necessary for compact form to prevent constructing & organizing tangling. cells. Chromatin fibers can unwind Functional segments of for DNA replication & DNA are known as genes. transcription. THE FLUID MOSAIC MODEL IS A BIOLOGICAL MODEL THAT EXPLAINS THE STRUCTURE AND FUNCTION OF THE CELL MEMBRANE PROPOSED BY SINGER AND NICOLSON (1972) WIDELY ACCEPTED AS FLUID MOSAIC MODEL. PROTEINS ARE EMBEDDED IN THE LIPID BILAYER IN A RANDOM DISTRIBUTION, FORMING A MOSAIC-LIKE STRUCTURE. THE PHOSPHOLIPIDS HAVE HYDROPHILIC HEADS FACING OUTWARD AND HYDROPHOBIC TAILS FACING INWARD.  ALGAE PLANTS Cell wall , made of cellulose, Pectins/Galactans, hemicellulose , mannans , silica and minerals like CELL WALL Cell wall , made of cellulose , hemicellulose , pectins , lignin and proteins. calcium carbonate. Cell wall is a external layer that gives shape, rigidity BACTERIA to the cell and protects the cell from mechanical damageLorem andipsum dolor sit amet infection, and is mainly made of Bacteria cell has 3 layer consectetur adipiscing elit, cellulose which is a complex substance and provides envelope. mauris laoreet class pulvinar structural strength to the cell. venenatis nam nulla, et porta Cell wall : peptidoglycan. nec Helps placerat the protect neque vivamus. cell in hypotonic external medium. Glycocalyx → Cell wall → Helps in cell-to-cell interaction and provides barrier Cell membrane to undesirable macromolecules. FUNGI : Cell wall , made of chitin. Glycocalyx: Outermost layer, made of polysaccharides, Bacteria cell has 2 types of FLAGELLUM MADE OFTHREE glycoproteins, & glycolipids. Cell membrane: SUBSTRUCTURES: Glycocalyx: MESOSOMES : DNA replication, HOOK: A hook-shaped structure Loose (Slime layer) Cell membrane formation, at the proximal end of the Thick (Capsule) made of Respiration, Secretion. filament that enters the cell wall Polypeptides. Mesosomes are analogous to and attaches to the basal body. mitochondria. BASAL BODY: Flagellum inside FLAGELLUM : Hair-like, motility the cell wall, firmly bound into The four types of bacteria organelle that helps bacteria the cell envelope. It contains the are based on their shape: move through liquids and rotary motor. BACILLUS: perform other functions. Rod-shaped bacteria. FILAMENT: A long, thin, COCCUS: structure made of the protein Spherical or oval-shaped flagellin. bacteria. GRAM STAINING PROCESS. SPIRILLUM: GRAM-POSITIVE BACTERIA: Bacteria are stained with Retain purple stain. Spiral-shaped bacteria. crystal violet dye. VIBRIO: Iodine. GRAM-NEGATIVE BACTERIA: Curved-shaped bacteria Alcohol-wash. Do not retain purple stain.  Prokaryotes VS Eukaryotes Prokaryotes (Pro = primitive; Eukaryotes (Eu – True, karyote = nucleus) karyotes – nucleus ) Undefined nucleus.(NUCLEOID) Well defined nucleus (unicellular) (multicellular) No membrane bound organelles. Membrane bound organelles. Plant and animal cells are different Prokaryotic cells may vary greatly cell walls, plastids and large central in shape and size. vacuole. Single circular chromosome More than one linear chromosomes and divide/ multiply rapidly. and slower cell division. Genetic material or DNA is Genetic material or DNA, is naked. contained within the nucleus Smaller in size. Comparatively large size. Ex: Bacteria, blue green Ex: Plants, Animals, Fungi , algae, mycoplasma protists. Ribosomes, Cell wall, Cell membrane common in both. Note :- Viruses lack membranes and hence do not show characteristics of life until they enter a living body and use its cell machinery to multiply.  Cell Organelles ENDOPLASMIC RETICULUM It is a large network of membrane-bound tubes and sheets. It looks like long tubules or round or oblong bags (vesicles). ER membrane is similar in structure to the plasma membrane. Has two types :- SER & RER ROUGH ENDOPLASMIC RETICULUM SMOOTH ENDOPLASMIC RETICULUM Rough surface due to presence of Smooth surface due to absence ribosomes on the surface. of ribosomes on the surface. Ribosomes are site of protein. Helps in lipid formation. synthesis. SER plays a crucial role in Transport the material b/w detoxifying many poisons and cytoplasm and nucleus. drugs. Manufactured proteins packaged In Animal cells lipids – like into vesicles and directed to steroidal hormones are different parts of the cell based on synthesized in SER. their function.  GOLGI APPARATUS It is a system of membrane-bound vesicles (flattened sacs) arranged approximately parallel to each other in stacks called cisterns. First described by Camillo Golgi. The material synthesized near the ER is packaged and dispatched to various targets inside and outside the cell through the Golgi apparatus Formation of Lysosomes. Storage, modification and packaging in vesicles. Converts simple sugars into complex sugars. Golgi bodies consist of many flat, disc – shaped sacs or cisternae of 0.5um to 1.0um diameter. Golgi apparatus is the important site of formation of glycoproteins and glycolipids. The Golgi cisternae are concentrically arranged near the nucleus with distinct convex cis or the forming face and concave trans or the maturing face. LYSOSOMES Lysosomes help keep the cell clean by digesting any foreign material and worn-out cell organelles. Structurally lysosomes are Membrane bounce sacs filled with digestive enzymes. These enzymes are made by RER. Waste disposal system of the cell. ‘Suicide Bags’ of a cell. The isolated lysosomal vesicles have been found to be very rich in almost all types of hydrolytic enzymes optimally active at acidic PH. ( Hydrolases – Esterases including lipases, phosphatases, glycosidases, peptidases, and nucleosidases. ). These enzymes are capable of digesting carbohydrates , proteins , lipids and nucleic acids. CENTRIOLES Centrioles are organelles found in most eukaryotic cells. Essential for a variety of cellular processes, including cell division, cell polarity, and intracellular traffic. Centrioles are not membrane-bound organelles.  MITOCHONDRIA Powerhouse of the cell. Double membrane. The outer membrane is porous while the inner membrane is deeply folded. Has its own DNA & Ribosomes. The mitochondria divide by fission. The energy is used to make new chemical compounds and carrying out mechanical activities of the cell. Help in generation of the energy currency of the cell ATP (Adenosine triphosphate). MICROBODIES Microbodies, also known as cytostomes, are small organelles found in the cytoplasm of cells that contain enzymes involved in metabolic pathways of sugars, amino acids, and fats. Many membrane bound minute vesicles called microbodies. Contain various enzymes , are present in both plants and animal cells. 0.2 – 1.5 micrometers in diameter. Do not contain separate DNA. Visible with an electron microscope. Spherical or vesicular shapes. VACUOLES Storage sacs for solid or liquid contents. Vacuoles are small-sized in animal cells while plant cells have very large vacuoles. The central vacuole of some plant cells may occupy 50- 90% of the cell volume. Many substances of importance in the life of the plant cell are stored in vacuoles. (amino acids, sugars). The vacuole is bound by a single membrane called TONOPLAST. In plants, the tonoplast facilitates the transport of a number of ions and other materials against concentration gradients into the vacuole. Their concentration is significantly higher in the vacuole than in the cytoplasm. In Amoeba the contractile vacuole is important for osmoregulation and excretion. Vacuoles are full of cell sap and provide turgidity and rigidity to the cell in plants. Eukaryotic Ribosomes (80S). Prokaryotic Ribosomes (70S). Subunit : 60S and 40S Subunit : 50S and 30S Mitochondria, Plastids( Chloroplast Ribosome) have 70S S : Svedberg unit stands for the sedimentation Cytoplasmic Ribosomes have 80S coefficient.  PLASTIDS Only found in plant cells. mRNA They also have their own DNA & RIBOSOMES. Are of two types :- Chromoplasts and Leucoplasts Chromoplasts with green pigment (chlorophyll ) are known as chloroplast. These help the cell in photosynthesis. Plastids are similar to mitochondria in external structure. In the chromoplasts fat soluble carotenoid pigments like carotene , xanthophyll and others are present. This gives the part of the plant a yellow , orange or red color. The leucoplasts are the colorless plastids of varied shapes and sizes with stored nutrients: 1. Amyloplasts store carbohydrates ( starch ), eg : potato 2. Elaioplasts store oils and fats. 3. Aleuroplasts store proteins. Majority of the chloroplasts of the green plants are found in the mesophyll cell of the leaves. The DNA present in chloroplast is circular , double stranded. RIBOSOME A ribosome is an intercellular structure made of both RNA and protein. Site of protein synthesis in the cell. The ribosome reads the messenger RNA (mRNA) sequence. mRNA translates that genetic code into a specified string of amino acids. Amino acids grow into long chains that fold to form proteins. Transfer RNA (tRNA) acts as a bridge between messenger RNA (mRNA) and amino acids to help ribosomes synthesize proteins. A polyribosome, also known as a polysome, is a group of ribosomes that are bound to a messenger RNA (mRNA) molecule. Polyribosomes are found in both prokaryotic and eukaryotic cells. The ribosomes are attached to the mRNA in a similar way to beads on a thread.  PLANT CELL ANIMAL CELL CELL WALL Present Absent CELL MEMBRANE Present Present Square or rectangular Irregular or round in CELL SHAPE in shape shape ENDOPLASMIC (ER) Present Present Present and lies on one Present and lies in the NUCLEUS side of the cell centre of the cell GOLGI APPARATUS Present Present Present but are very LYSOSOMES rare Present RIBOSOMES Present Present PLASTIDS Present Absent CYTOPLASM Present Present CENTRIOLE Absent in higher plants Present MITOCHONDRIA Present Present Large, centrally Usually small and VACUOLES positioned vacuole numerous separates the cell into different compartments, or # ENDOMEMBRANE SYSTEM organelles, such as nucleus, endoplasmic reticulum (ER), Golgi apparatus, lysosomes.  CELL DIVISION CELL DIVISION IS THE PROCESS BY WHICH A CELL SPLITS INTO TWO DAUGHTER CELLS MITOSIS MEIOSIS The process of cell division by which most of the Meiosis involves two consecutive divisions. cells divide for growth is called Mitosis. When a cell divides by meiosis it produces four In this, Mother cell divides to form two identical new cells instead of just two. daughter cells. The new cells only have half the number of The daughter cells have the same number of chromosomes than that of the mother cells chromosomes as mother cell. INTERPHASE INTERPHASE PROPHASE PROPHASE Spindle fibers METAPHASE METAPHASE Homologous chromosomes separate during anaphase I of ANAPHASE meiosis. ANAPHASE TELOPHASE TELOPHASE CYTOKINESIS CYTOKINESIS MITOSIS - TWO “DAUGHTER” CELLS MEOSIS - FOUR “DAUGHTER” CELLS This time I want your roll no. in PDF For CDS & NDA (1) 2025 1640 SELECTIONS IN NDA & CDS (2) 2024 2119 SELECTIONS IN AFCAT (2) 2024 सर नीचे, बस अपनी मेहनत।