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Cell - structure & function, this is a ppt presentation where u can learn about the cell and its structure and function
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- 2. Introduction to cell Celltheory Types of cell - Prokaryotic and Eukaryotic cell LEARNING OBJECTIVES Structure of cell Functions of cell Cell components Cell Organelles
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- 4. Cell is thebasic structural and functional unit of life or the body of living organisms. The cell is also known as a building block. Groups of cells combine to the form tissue. On the basis of numbers of cells, organisms can be categorized into two groups unicellular and multicellular. Unicellular are single celled and multicellular comprises many cells. INTRODUCTION TO CELL
- 5. Microorganisms were unknownbefore the invention of improved microscopes, and human beings were believed to be the fundamental building blocks of life. Early scientists could observe cells and make assumptions about what they witnessed. It is rarely possible to know how a cell operates under a microscope. Scientists made a big discovery that every living thing is made of cells. This idea is called the cell theory. Energy moves through cells. DNA is transferred from cell to cell, carrying genetic information. All cells share the same primary chemical makeup. CELL THEORY: AN OVERVIEW
- 6. HISTORY AND CONTRIBUTIONS Magnificationtechnology progressed to the point that it could be used to find cells due to ongoing advances in microscopes. Robert Hooke is usually credited with making this discovery, which launched cell biology as a field of study. The theory was first proposed in 1838 by German scientists Theodor Schwann and Matthias Jakob Schleiden. Since the discovery of the first cell, cell theory has evolved and grown, and many amazing experiments have been designed to demonstrate its many components.
- 7. POSTULATES OF MODERNCELL THEORY ( CELL PRINCIPLE OR CELL DOCTRINE ) (1) All living things are composed of cells. (2) Cell is the basic structural and functional unit of living things. (3) All cells arise from pre-existing cells. It also states that organisms grow by addition of cells and not by increase in the size of cells. (4) These cells contain hereditary information which is passed onto the next generation during cell division. (5) All cells are relatively the same in chemical composition and metabolic activities.
- 8. DEFINATION OF CELL Cellis the basic unit of all living organisms. Cell is defined as the basic structural, functional and biological unit of all living organisms. Eg: prokaryotic and eukaryotic cell.
- 9. DIFFERENCE BETWEEN PROKARYOTICAND EUKARYOTIC CELL Prokaryotic Cell Eukaryotic Cell Cell type - Unicellular and multi- cellular Cell size - Size ranges from 10 μm – 100 μm in diameter Cell wall - When present, chemically simple in nature Nucleus - Present Ribosomes - Present. Comparatively larger in size and linear in shape DNA arrangement - Linear Mitochondria - Present Cytoplasm - Present, cell organelles present Endoplasmic reticulum - Present Plasmids - Very rarely found in eukaryotes Ribosome - Large ribosomes Lysosome - Lysosomes and centrosomes are present Cell division - Through mitosis The flagella are larger in size Reproduction - Both asexual and sexual Example - Plant and Animal cell Cell type - Always unicellular Cell size - Ranges in size from 0.2 μm – 2.0 μm in diameter Cell wall - Usually present; chemically complex in nature Nucleus - Absent. Instead, they have a nucleoid region in the cell Ribosomes - Present. Smaller in size and spherical in shape DNA arrangement - Circular Mitochondria - Absent Cytoplasm - Present, but cell organelles absent Endoplasmic reticulum - Absent Plasmids - Present Ribosome - Small ribosomes Lysosomes and centrosomes are absent Cell division - Through binary fission The flagella are smaller in size Reproduction - Asexual Example - Bacteria and Archaea
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- 13. The cell structurecomprises individual components with specific functions essential to carry out life’s processes. These components include- cell wall, cell membrane, cytoplasm, nucleus, and cell organelles. Each cell contains a fluid called the cytoplasm, which is enclosed by a membrane. There are several biomolecules like proteins, nucleic acids and lipids present in the cytoplasm Cellular structures called cell organelles are suspended in the cytoplasm. Every organelle has a specific structure and is responsible for different functions. Cells provide structure and support to the body of an organism. The cell interior is organised into different individual organelles surrounded by a separate membrane. The nucleus (major organelle) holds genetic information necessary for reproduction and cell growth. Every cell has one nucleus and membrane-bound organelles in the cytoplasm. STRUCTURE OF A EUKARYOTIC CELL
- 14. Provide Structural Support- Cells form the basic structure of all living organisms, ensuring stability and shape. Form Protective Layers - Structures like the skin in animals and the cell wall in plants act as protective barriers. Facilitate Growth through Mitosis - Cells divide by mitosis, helping organisms grow by increasing their cell count. Enable Active and Passive Transport - Cells transport nutrients, gases, and waste products via active (energy-consuming) and passive (no energy) processes. Facilitate Diffusion of Small Molecules - Small molecules like oxygen and carbon dioxide move freely across cell membranes by diffusion. Perform Active Transport of Large Molecules - Larger molecules, such as glucose, are transported into or out of cells using energy. Produce Energy - Cells generate energy through processes like respiration in animals and photosynthesis in plants. Aid in Asexual Reproduction - Mitosis helps organisms reproduce by forming genetically identical daughter cells. FUNCTIONS OF A CELL
- 15. Support Sexual Reproduction- Meiosis allows for genetic variation by forming genetically distinct cells. Remove Waste Products - Cells eliminate waste generated during metabolic processes to maintain a clean internal environment. Enable Chemical Processes - Cells host numerous biochemical reactions necessary for survival, such as protein synthesis and energy metabolism. Support Structural Integrity in Plants - Xylem cells in vascular plants provide strength and support for standing upright. Maintain Homeostasis - Through transport mechanisms and energy usage, cells regulate their internal environment for optimal functioning. Facilitate Communication - Cells communicate via chemical signals (e.g., hormones) to coordinate functions across tissues and organs. Store Genetic Information - The nucleus of a cell contains DNA, which holds the instructions for the cell’s and organism’s functioning and reproduction.
- 16. WHAT IS ANORGANELLE? Organelles are the different structures inside a cell that each have different jobs or functions to complete within the cell.
- 17. LET’S LOOK ATTHE TYPES OF ORGANELLES
- 18. The cell membranesupports and protects the cell. It controls the movement of substances in and out of the cells. It separates the cell from the external environment. The cell membrane is present in all the cells. The cell membrane is the outer covering of a cell within which all other organelles, such as the cytoplasm and nucleus, are enclosed. It is also referred to as the plasma membrane. By structure, it is a porous membrane (with pores) which permits the movement of selective substances in and out of the cell. Besides this, the cell membrane also protects the cellular component from damage and leakage. cell membrane
- 19. The cell wallis the most prominent part of the plant’s cell structure. It is made up of cellulose, hemicellulose and pectin. The cell wall is present exclusively in plant cells. It protects the plasma membrane and other cellular components. The cell wall is also the outermost layer of plant cells. It is a rigid and stiff structure surrounding the cell membrane. It provides shape and support to the cells and protects them from mechanical shocks and injuries. cell wall
- 20. cytoplasm Cytoplasm is foundin both plant and animal cells and is made up of many dissolved molecules that can be used for other processes throughout the cell. The cytoplasm is a thick, clear, jelly- like substance present inside the cell membrane. Most of the chemical reactions within a cell take place in this cytoplasm. The cell organelles such as endoplasmic reticulum, vacuoles, mitochondria, ribosomes, are suspended in this cytoplasm.
- 21. Nucleus The “control center”of both plant and animal cells that controls growth and reproduction. The nucleus contains the hereditary material of the cell, the DNA. It sends signals to the cells to grow, mature, divide and die. The nucleus is surrounded by the nuclear envelope that separates the DNA from the rest of the cell. The nucleus protects the DNA and is an integral component of a plant’s cell structure.
- 22. Nucleolus The nucleolus ismade of RNA and protein. The part of both plant and animal cells that is found inside the nucleus. The nucleolus is the site of ribosome synthesis. Also, it is involved in controlling cellular activities and cellular reproduction.
- 23. chloroplast Chloroplast is the organellewhere photosynthesis takes place and is only found in plant cells. It contains the pigment called chlorophyll. Converts light energy of the sun into sugars that can be used by cells.
- 24. mitochondria Mitochondria is foundin both plant and animal cells and is known as the “powerhouse” of the cell. Performs cellular respiration, or the process in which nutrients are broken down and turned into energy the cell can use. Mitochondria are the powerhouses of the cell, producing energy in the form of ATP. They have a double membrane, with the inner membrane folded into cristae to increase energy production. Mitochondria have their own DNA, allowing them to make some proteins independently. They play a role in programmed cell death (apoptosis) by releasing specific signals.
- 25. Golgi apparatus Golgiapparatus is found in both plant and animal cells. Golgi bodies are called the cell’s post office as it is involved in the transportation of materials within the cell. Protein and Lipid Processing: The Golgi apparatus modifies, sorts, and packages proteins and lipids for delivery to different parts of the cell or for secretion outside the cell.
- 26. Smooth & ROUGH endoplasmicreticulum Smooth and Rough endoplasmic reticulum is found in both plant and animals cells and looks like a group of tubes. An organelle attached to the nucleus that’s important in the creation and storage of lipids. SER plays a primary role in the metabolism of carbohydrates, synthesis of lipids, steroids and proteins. RER Works with ribosomes attached to it to help with the synthesis and packing of proteins.
- 27. vacuole Vacuoles are foundin both plant and animal cells but are larger in plant cells. Vacuoles store food, water, and other waste materials in the cell. A storage bubble that stores food and nutrients the cell needs to survive.
- 28. ribosomes Small organelles that buildlong chains of amino acids for the cell. Ribosomes are found in both plant and animal cells and are known as the “protein builders” or protein factories of the cell.
- 29. Lysosome Lysosomes are only foundin animal cells. Helps digest and break down food in the cell with the help of enzymes that are stored here.
- 30. Microtubules Microtubules are only foundin animal cells. Helps provide structure to the cell and also helps with cell division.
- 31. Centrioles Centrioles are only foundin animal cells and are made up of multiple microtubules Helps the cell divide during mitosis and meiosis..
- 32. peroxisome Peroxisomes are foundin both plant and animal cells. An organelle that digests nutrients and helps break down toxic materials. They have digestive enzymes in their membranes to digest nutrients like amino acids, cholesterol, and fatty acids.
- 33. THAT’S ALL OFTHEM! HERE’S A QUICK GLOSSARY GO THROUGH..
- 34. CHAPTER GLOSSARY: Cell: Acell is the tiniest part of a living thing that can still do all the jobs needed to keep it alive. It's like the smallest building block of life. Organ: A part of the body (like the heart or lungs) made up of groups of cells working together to do a specific job. Tissue: A group of similar cells that work together to perform a specific function, like muscle tissue that helps you move. Energy: The power that living things need to do things like move, grow, or heal. DNA: A special molecule inside cells that contains instructions for how a living thing looks and works. Genetic Information: The "blueprint" in DNA that decides traits like eye color, height, and how cells function. Homeostasis: A process that keeps everything in the body balanced and working right, like keeping your temperature just right. Evolution: The idea that living things slowly change over a long time to better survive in their environment. Hypothesis: A scientific idea that is tested and often becomes a widely accepted explanation when supported by evidence. Diffusion : Diffusion is the movement of particles (like gases or liquids) from an area of high concentration to an area of low concentration, until they are evenly spread out.
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