Copyright © 2010 Pearson Education, Inc. The Organelles Membranous Organelles –Five types of membranous organelles: Endoplasmic reticulum (ER) Golgi apparatus Lysosomes Peroxisomes Mitochondria
Copyright © 2010 Pearson Education, Inc. The Organelles Endoplasmic Reticulum (ER) –Functions: Synthesis of proteins, carbohydrates, and lipids Storage of synthesized molecules and materials Transport of materials within the ER Detoxification of drugs or toxins
Copyright © 2010 Pearson Education, Inc. The Organelles Endoplasmic Reticulum (ER) –Smooth endoplasmic reticulum (SER): No ribosomes attached Synthesizes lipids and carbohydrates: –phospholipids and cholesterol (membranes) –steroid hormones (reproductive system) –glycerides (storage in liver and fat cells) –glycogen (storage in muscles)
Copyright © 2010 Pearson Education, Inc. The Organelles Endoplasmic Reticulum (ER) –Rough endoplasmic reticulum (RER): Surface covered with ribosomes: –active in protein and glycoprotein synthesis –folds polypeptide protein structures –encloses products in transport vesicles
Copyright © 2010 Pearson Education, Inc. The Endoplasmic Reticulum Figure 3-13
Copyright © 2010 Pearson Education, Inc. Organelles and the Cytoplasm Golgi Apparatus –Vesicles enter forming face and exit maturing face: Secretory vesicles: –modify and package products for exocytosis Membrane renewal vesicles: –add or remove membrane components Lysosomes: –carry enzymes to cytosol Functions of the Golgi Apparatus
Copyright © 2010 Pearson Education, Inc. The Golgi Apparatus Figure 3-14
Copyright © 2010 Pearson Education, Inc. The Organelles Lysosomes –Powerful enzyme-containing vesicles Functions of Lysosomes –Clean up inside cells: Break down large molecules Attack bacteria Recycle damaged organelles Eject wastes by exocytosis –Autolysis Auto- = self, lysis = break Self-destruction of damaged cells: –lysosome membranes break down –digestive enzymes are released –cell decomposes –cellular materials recycle
Copyright © 2010 Pearson Education, Inc. The Organelles Peroxisomes –Are enzyme-containing vesicles: Break down fatty acids, organic compounds Produce hydrogen peroxide (H 2 O 2 ) Replicate by division
Copyright © 2010 Pearson Education, Inc. The Organelles Mitochondria –Have smooth outer membrane and inner membrane with numerous folds (cristae) –Matrix: Fluid around cristae –Mitochondrion takes chemical energy from food (glucose): Produces energy molecule ATP
Copyright © 2010 Pearson Education, Inc. The Organelles Mitochondria –Aerobic metabolism (cellular respiration) Mitochondria use oxygen to break down food and produce ATP glucose + oxygen + ADP carbon dioxide + water + ATP Glycolysis: –glucose to pyruvic acid (in cytosol) Tricarboxylic acid cycle (TCA cycle): –pyruvic acid to CO 2 (in matrix) Electron transport chain –inner mitochondrial membrane
Copyright © 2010 Pearson Education, Inc. Mitochondria Figure 3-15
Copyright © 2010 Pearson Education, Inc. Nuclear Structure and Contents Nucleus –Largest organelle –The cell’s control center Nuclear Envelope –Double membrane around the nucleus Perinuclear Space –Between the two layers of the nuclear envelope Nuclear Pores –Communication passages
Copyright © 2010 Pearson Education, Inc. The Nucleus Figure 3-16
Copyright © 2010 Pearson Education, Inc. Nuclear Structure and Contents DNA –All information to build and run organisms Nucleoplasm –Fluid containing ions, enzymes, nucleotides, and some RNA Nucleoli –Are related to protein production –Are made of RNA, enzymes, and histones –Synthesize rRNA and ribosomal subunits Chromatin –Loosely coiled DNA (cells not dividing) Chromosomes –Tightly coiled DNA (cells dividing)
Copyright © 2010 Pearson Education, Inc. Information Storage in the Nucleus DNA –Instructions for every protein in the body Gene –DNA instructions for one protein Genetic Code –The chemical language of DNA instructions: Sequence of bases (A, T, C, G) –Triplet code: 3 bases = 1 amino acid