Bio Summary _ Cells

1 Organisation of the Living Organism 1) Cell – a unit of life - made up of living matter called protoplasm (protos = first, plasm = form) 2) Protoplasm – jelly-like substance - chemical reactions take place here - contains 70% water - composition of fat, carbohydrates and proteins may vary. It depends of which cell protoplasm is found in the body. Example: Protoplasm in muscle cell will contain more carbohydrate to provide energy while protoplasm in the hair will contain more protein (hair is made up of the protein keratin). - MADE UP OF 3 PARTS : NUCLEUS , CYTOPLASM AND PLASMA MEMBRANE 3) The table below shows the 3 main constituents of protoplasm: Nucleus Cytoplasm Plasma Membrane -Surrounded by nuclear -Forms larger part of the -Selectively permeable (DO membrane (separates cell NOT USE the term nucleus from surrounding PARTIALLY cytoplasm). Inside nuclear PERMEABLE) membrane: denser protoplasm called It controls substances NUCLEOPLASM leaving and entering the cell. -In the nucleoplasm: -Contains: a) CHROMATIN (contains a) Mitochondria (rod DNA and proteins). shaped structures) [in Chromatin controls cell charge of releasing energy division, cell repair and cell from cell respiration: Look activities at chapter on Respiration. b) Spherical structures Energy used for growth and called nucleoli (in charge of reproduction building proteins) b) Vacuoles (fluid filled space enclosed by a membrane). Contain water and food substances. c) Centrioles (involved in cell division) d) Golgi Apparatus (involved in sorting and packaging proteins and transporting them to other parts of the cell, synthesize Copyright: Stephanie Teo Acknowledgments: All pictures taken from: Comprehensive Biology: A Course For ‘O” Level by Lam Peng Kwan Unless stated otherwise

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** Cells without nucleus eg red blood cells have a short life span

new cell walls, form lysozymes (small structures that contain enzymes) ** Animal cells got many **May surround vacuoles small vacuoles. Plant cells in the cell got 1 big vacuole ** Plant cells have NO centrioles ** Golgi Apparatus CANNOT be seen under the light microscope

4) Diagram of a general animal cell

Copyright: Stephanie Teo Acknowledgments: All pictures taken from: Comprehensive Biology: A Course For ‘O” Level by Lam Peng Kwan Unless stated otherwise