Cell Structure and Function PDF

Summary

This chapter discusses cell structure and function, covering the cell theory, cell types (prokaryotic and eukaryotic), cell organelles (e.g., nucleus, ER, ribosomes, Golgi apparatus), cytoskeleton, cell membrane, and cell transport mechanisms (passive and active transport, osmosis).

Full Transcript

Chapter 3 UNIT 3: THE CELL CELL STRUCTURE AND FUNCTION The Cell Theory: (1600s – 1800s) 3 principles: 1. All organisms are made of cells. The Cell Theory: (1600s – 1800s) 3 principles: 1. All organisms are made of cells. 2. The cell is the most basic unit of life. The Cell Theory: (1600...

Chapter 3 UNIT 3: THE CELL CELL STRUCTURE AND FUNCTION The Cell Theory: (1600s – 1800s) 3 principles: 1. All organisms are made of cells. The Cell Theory: (1600s – 1800s) 3 principles: 1. All organisms are made of cells. 2. The cell is the most basic unit of life. The Cell Theory: (1600s – 1800s) 3 principles: 1. All organisms are made of cells. 2. The cell is the most basic unit of life. 3. All cells are produced by pre-existing cells. All cells share certain characteristics: 1. genetic material (DNA) 2. cell membrane cell membrane 3. ribosomes Bacterium (colored SEM; magnification 8800x) Two cell types: 1. Eukaryotic cells have… a nucleus membrane-bound nucleus organelles organelles Two cell types: 2. Prokaryotic cells do not have… a nucleus membrane-bound nucleus organelles organelles 3.2 Cell Organelles Cytoskeleton Composed of 3 types of protein fibers – Microtubules – Intermediate filaments – Microfilaments 3.2 Cell Organelles Cytoskeleton Functions: – provides strength and shape – positions organelles – assists in cell division – aids in cell movement 3.2 Cell Organelles Protein Production, Modification, and Transportation Nucleus – stores genetic information (DNA) 3.2 Cell Organelles Protein Production, Modification, and Transportation Endoplasmic reticulum (ER) 3.2 Cell Organelles Protein Production, Modification, and Transportation Endoplasmic reticulum (ER) There are two types of ER: – Rough (R) endoplasmic reticulum – Smooth (S) endoplasmic reticulum 3.2 Cell Organelles Protein Production, Modification, and Transportation Endoplasmic reticulum (ER) – Functions: – production and transportation of proteins (R) – production of lipids (S) – neutralization of toxins (S) 3.2 Cell Organelles Protein Production, Modification, and Transportation Ribosomes – machines, which link amino acids to form proteins 3.2 Cell Organelles Protein Production, Modification, and Transportation Vesicles – small, membrane sacs that store and transport materials 3.2 Cell Organelles Protein Production, Modification, and Transportation Golgi Apparatus – membrane structures in which proteins are processed, sorted, and tagged for shipping 3.2 Cell Organelles Other organelles have various functions. Mitochondria – produce energy for the cell (ATP) 3.2 Cell Organelles Other organelles have various functions. Vacuoles – membrane-bound sacs that store water or other materials (common to plant cells) 3.2 Cell Organelles Other organelles have various functions. Lysosomes – contain digestive enzymes for breaking down materials 3.2 Cell Organelles Other organelles have various functions. Centrioles – help divide DNA (mitosis) – form cilia and flagella (provide movement) 3.2 Cell Organelles Organelles specific to plant cells A cell wall – provides rigid support. 3.2 Cell Organelles Organelles specific to plant cells Chloroplasts – convert solar energy to chemical energy (photosynthesis) 3.2 Cell Organelles Cell Membrane “Fluid Mosaic Model” Allows only certain substances to cross = selective permeability 3.2 Cell Organelles Cell Membrane “Fluid Mosaic Model” Allows only certain substances to cross = selective permeability Enables cell to communicate with the outside Nucleus Cell Smooth endoplasmic membrane reticulum Cytosol Lysosome Mitochondrion Rough endoplasmic reticulum Centrioles Ribosomes Golgi apparatus Secretion being released Microtubule from cell by vesicle Cytoskeleton Intermediate filaments Chapter 3 UNIT 3: THE CELL CELL TRANSPORT O Concentration – the amount of solute / the volume of- solution · solute = sugar solvent water B low · E less sugap Hypotonic solution more solvent Concentration gradient – a condition in which areas of high and low concentration exist side by side. A high more sugarent) Hypertensa passive transport (no energy ⑧ * Particles always diffuse from an area of C higher concentration to an area ofG lower concentration. Cell Transport: Important Terms Concentration Concentration Gradient Passive Transport: No energy required Diffusion Facilitated Diffusion Equilibrium Dye Diffusion in water (no cell membrane selective permeability) equilibrium high low Diffusion – the random movement of particles - (across a cell membrane) from an area- higer to an area ofClower concentration Diffusion across the cell membrane ① ② ③ O O Net Diffusion Net Diffusion Equilibrium ↳flow of solute particles moving in a direction: bigger Net diffusion O = thath opposite direction Equilibrium – the point at which a concentration gradient no longer exists Facilitated Diffusion Passiveansport gradient * * Facilitated Diffusion – the diffusion of particles across a cell membrane with the help of a membrane protein channel transport , , carries Cell Transport: Important Terms - Concentration ~ Concentration Gradient ~ Passive Transport: no energy required ([H] à [L]) Diffusion Facilitated Diffusion Equilibrium Active Transport: requires energy Protein Pumps Bulk Transport Endocytosis Exocytosis Active Transport: 1) Protein Pumps O C O Active Transport – the movement of particles (across a membrane) from an area of Olower to G higher concentration. (Requires Energy) ATP = Active Transport: 2) Bulk Transport require large molecule energy cell membrane A) Endocytosis reside B) Exocytosis Active Transport: 2) Bulk Transport out in & Al Cell Transport: Important Terms Concentration Osmosis Concentration Gradient Hypotonic Passive Transport Isotonic Diffusion Hypertonic Facilitated Diffusion Equilibrium Active Transport Protein Pumps Bulk Transport Endocytosis Exocytosis higha , Osmosis: Notes from class Osmosis & Tonicity: (Animal Cells) equilibrium g 00 00 o o O C Og O Osmosis & Tonicity: (Plant Cells) Plasmolysed Flacid Turgid Cell Shrince brow in size cytolosis - when cell burst Osmosis & Tonicity: (Plant Cells) / Plasmolysed Flacid Turgid Hypotonic Hypertonic A - Isotonic S H2O > - - C Osmosis PRACTICE: The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4M glucose and 0.6M sodium chloride (NaCl), and side B is filled with a solution containing 0.8M glucose and 0.2M sodium chloride. Initially, the volume in both arms is the same. Side A: Side B: 0.4M glucose 0.8M glucose 0.6M NaCl 0.2M NaCl 1) Make a sketch to summarize the predicted conditions within the U-tube if it was observed again after 24 hours. 2) Explain the changes you have predicted based on your understanding of osmosis. PRACTICE: The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4M glucose and 0.6M sodium chloride (NaCl), and side B is filled with a solution containing 0.8M glucose and 0.2M sodium chloride. Initially, the volume in both arms is the same. Side A: Side B: 0.4M glucose 0.8M glucose 0.4M NaCl 0.4M NaCl 1) Make a sketch to summarize the predicted conditions within the U-tube if it was observed again after 24 hours. 2) Explain the changes you have predicted based on your understanding of osmosis.

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