PDF Plant and Animal Cell GB1

Components of the Cell: Major Parts of the Cell General Biology 1[1/2] Science, Technology, Engineering, and Mathematics In cities, buildings cater various forms of services to increase productivity. They also have structures and other security measures that regulate the entry and exit of people...

Components of the Cell: Major Parts of the Cell General Biology 1[1/2] Science, Technology, Engineering, and Mathematics In cities, buildings cater various forms of services to increase productivity. They also have structures and other security measures that regulate the entry and exit of people. 2 Our cells also rely on biomolecules that provide shape and rigidity to them. In addition, our cells manage to become selective to the molecules that will move through it. 3 How can one distinguish the major parts of the cell? 4 Learning Competency At the end of the lesson, you should be able to do the following: Describe the structure and function of the major organelles (STEM_BIO11/12-Ia-c-2). 5  Learning Objectives At the end of the lesson, you should be able to do the following: Distinguish between the different structural components of the plasma membrane. Describe the diverse roles of proteins in membranes. Compare the structure and function of microfilaments, intermediate filaments, and microtubules. 6  Learning Objectives At the end of the lesson, you should be able to do the following: Describe the function and composition of cytoplasm. Describe the structure and function of the cell wall. 7 Overview of the Regions of the Cell The cell has three major divisions, namely, the plasma membrane, the cytoplasm, and the nucleus. 8 Overview of the Regions of the Cell The cell consists of both membrane-bound and non- membrane-bound organelles. 9  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane Cytoskeleton Cytoplasm Cell Wall The plasma membrane is the cell’s primary barrier. 10  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane Cell membrane or plasma membrane separates the cytoplasm from external Cytoskeleton environment. Cytoplasm It comprises the following: ❖ phospholipids ❖ glycolipids Cell Wall ❖ cholesterol ❖ glycoproteins ❖ membrane proteins 11  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane Each of the phospholipids consists of the following: Cytoskeleton ○ head region phosphate group Cytoplasm hydrophilic ○ tail region Cell Wall two fatty acid chains hydrophobic 12  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane Phospholipids make up the phospholipid bilayer. Cytoskeleton ○ two phospholipid layers Phosphate heads face the Cytoplasm cytoplasm and the cell’s exterior. Fatty acid tails are sandwiched. Cell Wall 13  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane The fluid mosaic model describes the membrane structure. Cytoskeleton ○ mosaic of different molecules such as proteins, sugars, and cholesterol Cytoplasm ○ fluidity due to its natural viscosity Cell Wall 14  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane Membrane fluidity is determined by: ○ the “kinks” in the fatty acid tails of Cytoskeleton the phospholipids ○ the cholesterol molecules which act Cytoplasm as regulators of fluidity Cell Wall 15  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane Selective permeability is an important property of the lipid bilayer, in which it Cytoskeleton only allows certain molecules to move into and out of the cell. Cytoplasm Cell Wall 16  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane Permeable Cytoskeleton Lipids Alcohol small molecules Cytoplasm carbon oxygen nitrogen dioxide water Cell Wall 17  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane Impermeable Cytoskeleton polar molecules large molecules Cytoplasm amino nucleic glucose proteins Cell Wall acids acids 18  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane Cytoskeleton Cytoplasm Cell Wall Transport proteins in the membrane may either be in the form of carrier proteins or channel proteins 19  Structural Components of the Plasma Membrane Roles of Roles of Structure Lipid Bilayer Membrane Proteins Plasma Membrane channel passageway of certain proteins molecules Membrane Proteins Cytoskeleton change conformation carrier proteins to transport molecules Cytoplasm cell recognition detect invading proteins pathogens Cell Wall receptor binding of molecules to proteins trigger responses 20  The Cytoskeletal Elements Intermediate Microtubules Microfilaments Filaments Plasma Membrane This consists of a network of Cytoskeleton protein fibers that gives the cell its Cytoplasm structural framework. Cell Wall The cytoskeletal elements can be observed by using fluorescence techniques. 21  The Cytoskeletal Elements Intermediate Microtubules Microfilaments Filaments Plasma Membrane Cytoskeleton Cytoplasm Cell Wall In addition to providing a structural framework to the cell, the cytoskeleton also serves other functions such as movement of organelles, macromolecules, and chromosomes. 22  The Cytoskeletal Elements Intermediate Microtubules Microfilaments Filaments Plasma Membrane These consist of helically arranged globular proteins called tubulin. Cytoskeleton Cytoplasm Cell Wall A microtubule is a helix of ɑ-tubulin and β-tubulin subunits. 23  The Cytoskeletal Elements Intermediate Microtubules Microfilaments Filaments Plasma Membrane It radiate from the centrosomes Form spindle fibers that move chromosomes Cytoskeleton Cytoplasm Cell Wall A microtubule is a helix of ɑ-tubulin and β-tubulin subunits. 24  The Cytoskeletal Elements Intermediate Microtubules Microfilaments Filaments Plasma Membrane They consist of long fibers of Cytoskeleton actin protein, making them Cytoplasm the thinnest cytoskeleton. Cell Wall Fluorescent actin microfilaments from mouse embryo 25  The Cytoskeletal Elements Intermediate Microtubules Microfilaments Filaments Plasma Membrane They help facilitate cell and Cytoskeleton organelle movement. Cytoplasm They can help change the Cell Wall shape of the cell. Fluorescent actin microfilaments from mouse embryo 26  The Cytoskeletal Elements Intermediate Microtubules Microfilaments Filaments Plasma Membrane Helps maintain cell shape Anchors the nucleus Cytoskeleton Cytoplasm Cell Wall Intermediate filaments provide structural integrity to the plasma membrane 27  Structural Components of the Cytoplasm Plasma Membrane This is where all different subcellular Cytoskeleton structures are suspended. Cytoplasm Cross-section view of a plant cell showing organelles in Cell Wall the cytoplasm 28  Structural Components of the Cytoplasm Plasma Membrane It is composed of the cytosol, a semifluid Cytoskeleton solution that consists of Cytoplasm water and inorganic and Cross-section view of a plant cell showing organelles in Cell Wall organic the cytoplasm molecules. 29  Structural Components of the Cell Wall Plasma Membrane Cell wall is a rigid structure that surrounds the cell membrane. Cytoskeleton It helps maintain the shape of cells and prevent them from bursting. Cytoplasm Cell Wall 30  Structural Components of the Cell Wall Plasma Membrane Most bacteria have cell wall made up of Cytoskeleton peptidoglycan. Cytoplasm The cell wall in some fungi Cell Wall consists of Bacterial cell capsule chitin. consists of peptidoglycan 31  Structural Components of the Cell Wall Plasma Membrane In plant cells, the cell wall consists of mesh-like cellulose fibers. Cytoskeleton Cytoplasm Cell Wall Plant cell walls prevent the cell from bursting should excess water is absorbed. 32 Is it possible to make an artificial cell from scratch? 33  Let’s Sum It Up! The cell is divided into main regions: ○ The plasma membrane is mostly composed of phospholipids. It serves as the primary barrier of the cell and is semi-permeable in nature. ○ The cytoskeleton is composed of microtubules, microfilaments, and intermediate filaments. The cytoskeletal elements provide support and framework and facilitate motility in cells. 34  Let’s Sum It Up! The cell is divided into main regions: ○ The cytoplasm is a jelly-like structure composed of the semi-fluid cytosol where all organelles and other cellular contents are immersed or suspended. ○ The cell wall is made up of peptidoglycan in bacterial cells and cellulose in plant cells. It gives a rigid structure for the cell and prevents it from bursting. 35 Let’s Sum It Up! The plasma membrane, cytoplasm, cytoskeleton, and cell wall all contribute to the cell’s maintenance and survival. 36 Lesson 1.3 Components of the Cell II: Subcellular Organelles General Biology 1 Science, Technology, Engineering, and Mathematics The cell can be compared to a factory building. It creates a barrier that collects all its machinery and employees in their proper places. 38 In a cell, the organelles represent the machinery and employees that work in a factory building. These organelles have their own specific functions that work for different cellular processes. 39 How do organelles help in ensuring that functions required for life are done? 40  Learning Competency At the end of the lesson, you should be able to do the following: Describe the structure and function of subcellular organelles (STEM_BIO11/12-Ia-c-2). 41  Learning Objectives At the end of the lesson, you should be able to do the following: Describe the composition and role of nucleus and ribosomes in genetic control of the cell. Distinguish how the compositions and roles of organelles in the endomembrane system differ from one another. Compare the composition and role of chloroplast and mitochondria in providing energy for the cell. 42 Why do membrane bound organelles exist? 43  The Origin of the Membrane Bounded Organelles double membrane of large eukaryotic cell mitochondria & engulfed prokaryote chloroplasts Endosymbiotic theory mitochondria & chloroplasts have their result of invagination own genetic material 44 The Origin of the Membrane Bounded Organelles Summary of Endosymbiotic theory 45 How do the organelles of the cell differ in their own functions? 46  Subcellular Organelles Genetic control of the cell (nucleus and ribosomes) Organelles of Endomembrane system the cell are (endoplasmic reticulum, Golgi divided into bodies, lysosomes, peroxisomes, and vacuoles) three groups. Energy houses (mitochondria and chloroplast) 47  The Genetic Control of the Cell Nucleus Ribosome Structure of the Nucleus This is a prominent, usually oval structure in a eukaryotic cell. It is located in almost the center of the cell. Cross-section view of a nucleus48  The Genetic Control of the Cell Nucleus Ribosome Parts of the Nucleus Nucleoplasm is the semifluid matrix. Nuclear envelope separates the nucleus from the cytoplasm Cross-section view of a nucleus49  The Genetic Control of the Cell Nucleus Ribosome Parts of the Nucleus Nuclear pores permit the passage of ribosomal subunits and mRNA out of the nucleus into the cytoplasm. Cross-section view of a nucleus50  The Genetic Control of the Cell Nucleus Ribosome Function of the Ribosomes Ribosomes are the organelles that use instructions from the nucleus, written in mRNA, to build proteins. The location of free ribosomes and bound ribosomes. 51  The Genetic Control of the Cell Nucleus Ribosome Free and Bound Ribosomes Free ribosomes are found in the cytosol. Bound ribosomes are attached to the outside of the endoplasmic The location of free ribosomes reticulum or nuclear and bound ribosomes. envelope. 52  The Endomembrane System Endoplasmic reticulum Golgi bodies Lysosomes Peroxisomes Vacuoles A photo showing the rough and smooth ER 53  The Endomembrane System Endoplasmic reticulum Two Types of Endoplasmic Reticulum Golgi bodies Rough ER have thousands of ribosomes attached to the outer surface which give Lysosomes this organelle a “rough” appearance. Their main role is to produce proteins. Peroxisomes Smooth ER does not have attached Vacuoles ribosomes. This organelle produces lipids. 54  The Endomembrane System Endoplasmic reticulum Function of the Golgi Bodies These serve Golgi bodies functions similar to a warehouse Lysosomes and processing center, processing Peroxisomes products of the Vacuoles ER. Golgi apparatus or Golgi bodies 55  The Endomembrane System Endoplasmic reticulum Function of the Lysosomes Golgi bodies Lysosomes Peroxisomes Vacuoles Illustration of lysosomal activity. 56  The Endomembrane System Endoplasmic reticulum Function of the Peroxisomes These contain Golgi bodies enzymes and serve as metabolic Lysosomes assistance to organelles and Peroxisomes specialize in synthesizing & Vacuoles Role of peroxisomes breaking down lipids. 57  The Endomembrane System Endoplasmic reticulum Function of the Vacuoles These serve as Golgi bodies a storage of water, organic Lysosomes nutrients, variety of salts, Peroxisomes sugar & some weak acids. Vacuoles Lateral view of a vacuole 58  The Energy Houses of the Cell Mitochondrion This is known as the “powerhouse of the cell” Cross-section of a Mitochondrion 59  The Energy Houses of the Cell Chloroplast This is unique to plant and algae cells. This organelle perform photosynthesis. Cross-section of a Chloroplast 60 Mitochondria vs Chloroplast 61  Let’s Sum It Up! A eukaryotic cell houses DNA in a nucleus. Nuclear pores allow the exchange of materials through the nuclear envelope. The smooth endoplasmic reticulum synthesizes lipids while the rough endoplasmic reticulum synthesizes proteins. 62  Let’s Sum It Up! Golgi bodies work together with the endoplasmic reticulum to synthesize, store, transport, and release molecules. Lysosomes, vacuoles, and peroxisomes are the digestion centers of the cell. 63  Let’s Sum It Up! The mitochondria house the cellular respiration of the cell. Photosynthesis occurs in the chloroplasts which are only present in plant and algal cells. 64 Let’s Sum It Up! Graphical representation of the subcellular organelles 65 Let’s Sum It Up! 66