Eukaryotic Cell Structure and Function PDF

EUKARYOTIC CELL STRUCTURE AND FUNCTION CELLS Smallest living unit Most are microscopic  EUKARYOTIC CELLS Domain Eukarya Protists Fungi Plants Animals Cells contain: Membrane-bound nucleus Specialized organelles Plasma membrane  PLASMA MEMBRANE Contains...

EUKARYOTIC CELL STRUCTURE AND FUNCTION CELLS Smallest living unit Most are microscopic  EUKARYOTIC CELLS Domain Eukarya Protists Fungi Plants Animals Cells contain: Membrane-bound nucleus Specialized organelles Plasma membrane  PLASMA MEMBRANE Contains cell contents Double layer of phospholipids & proteins Mechanical cell boundary, selectively permeable barrier with transport systems, mediates cell-cell interactions and  CYTOPLASM Viscous fluid (cytosol) containing organelles Composed of interconnected filaments & fibers  CYTOSKELET ON Consists of filaments & fibers Made of 3 fiber types: Microfilaments Microtubules Intermediate filaments Functions: mechanical support anchor organelles  ENDOPLASMIC RETICULUM 1. Rough Endoplasmic Reticulum Studded with ribosomes on cytoplasm side Protein anabolism Modifies proteins (adding to sugar to protein resulting in glycoproteins) 2. Smooth Endoplasmic Reticulum Synthesis of lipids (phospholipids, steroids), Metabolism of carbohydrates (glycogen) Detoxification of drugs (barbiturates) and poisons RIBOSOMES Serve in protein synthesis Composed of rRNA ( consists of large and small subunit made in nucleolus) May be located: On the endoplasmic reticulum (thereby making it “rough”), or Free in the cytoplasm, either singly or in groups called polyribosomes GOLGI APPARATUS Consists of 3-20 flattened, curved saccules Resembles stack of hollow pancakes Modifies proteins and lipids 1. Packages them in vesicles 2. Receives vesicles from ER on cis face 3. Prepares for “shipment” in vesicles from trans face (within cell) LYSOSOMES Contain digestive enzymes Intracellular digestion Functions Aid in cell renewal Break down old cell parts  MITOCHONDRI A Energy production through use of the tricarboxylic acid cycle, electron transport, oxidative phosphorylation, and other pathways Bounded by double membrane Cristae – Infoldings of inner membrane that encloses matrix Matrix – Inner semifluid  CHLOROPLAST Captures light energy to drive S cellular machinery Photosynthesis Synthesizes carbohydrates from CO2 & H2O Makes own food using CO2 as only carbon source Energy-poor compounds converted to enery rich compounds  NUCLEUS Repository for genetic information, control center for cell Separated from cytoplasm by nuclear envelope Consists of double layer of membrane Nuclear pores permit exchange between nucleoplasm & cytoplasm NUCLEOLUS Most cells have 2 or more Directs synthesis of RNA Ribosomal RNA synthesis, ribosome construction CELL WALL Carbohydrate frameworks for mechanical support in bacteria, protists, fungi, and plants Surrounds plasma membrane Strengthen and give shape to the cell CELL WALL DIFFERENCES Plants – mostly cellulose Fungi – contain chitin  CILIA & FLAGELLA Cell movement Hair-like projections from cell surface that aid in cell movement In center are two single microtubules This 9 + 2 pattern used by all cilia & flagella In eukaryotes, cilia are much shorter than flagella Cilia move in coordinated waves like oars Flagella move like a propeller or cork screw  VACUOLES Membrane bound storage sacs Store materials that occur in excess Functions: Storage of water, nutrients, pigments, and waste products Development of turgor pressure