YIJC [H2] CI1.1_Organelles and Cellular Structures (N)

2024 JC1 BIOLOGY LECTURE NOTES CORE IDEA 1: THE CELL AND BIOMOLECULES OF LIFE TOPIC 1.1: ORGANELLES AND CELLULAR STRUCTURES Learning Outcomes You should be able to: (a) outline the cell theory with the understanding that cells are the smallest unit of life, all cells come from pre-existing cells, and living organisms are composed of cells (b) interpret and recognise drawings, photomicrographs and electronmicrographs of the following membrane systems and organelles: rough and smooth endoplasmic reticulum, Golgi body, mitochondria, ribosomes, lysosomes, chloroplasts, cell surface membrane, nuclea r envelope, centrioles, nucleus and nucleolus (for practical assessment, candidates may be required to operate a light microscope, mount slides and use an eyepiece graticule and a stage micrometer) (c) outline the functions of the membrane systems and organelles listed in (b) (d) describe the structure of a typical bacterial cell (small and unicellular, peptidoglycan cell wall, circular DNA, 70S ribosomes and lack of membrane-bound organelles) Textbooks and References Campbell, Urry, Cain, Wasserman, Minorsky, Reece (2018) Biology – A Global Approach (11th Edition)(Global Edition) Chapter 7: Cell Structure & Function pg. 163 – 195 (Pearson Publication) ISBN-10 1-292-17043-3 Note: These textbooks and references are available in our library. You may wish to borrow them to supplement your reading when necessary. H2

2 Contents Introduction 3 A bridge to O Level Biology 4 The Cell Theory 6 Cell Types 9 Cell Size 10 A bridge to O Level Biology 12 Functions of membrane systems and organelles in cells 13 Cell Surface Membrane 16 Nucleus 17 Nuclear Envelope 19 Nucleolus 19 Endomembrane system 20 Endoplasmic Reticulum (ER) 21 Rough Endoplasmic Reticulum (rER) 22 Smooth Endoplasmic Reticulum (sER) 23 Golgi Apparatus (Golgi body) 24 Lysosomes 26 Ribosomes 34 Centrioles 35 Cytoskeleton 36 A bridge to O Level Biology 37 Structure of a Typical Bacterial Cell 38 Peptidoglycan cell wall 38 Circular DNA 39 70S ribosomes 39 Summary: Overview of an animal cell ultrastructure with the associated functions 40 Annex A: Microscopy 41 Annex B: Cell Fractionation 42 Annex C: Steps involved in the secretory pathway 44 Annex D: Answers 47

3 Introduction The following questions should help you frame your learning: 1. Why is a cell the basic unit of life and how does it promote continuity of life? 2. How is the basic unit crucial in understanding life? 3. What are the differences between cells of prokaryotes and eukaryotes, between cells of plants and animals, and between cells of unicellular and multicellular organisms? Sub-cellular structures provide the means to drive cellular processes Knowing how cellular structures facilitate specific cellular processes is fundamental to explaining how life ‘works’. The cell theory states that the cell is the smallest and most basic unit