TMJC Cell Communication Notes

Page 1 of 30 Tampines Meridian Junior College JC2 H2/9744 Biology 2024 Core Idea 3B 12. Energy and Equilibrium – Communication in Multicellular Organisms SYLLABUS OVERVIEW No. Overarching Idea Topics 1 Core Idea 1 The Cell and Biomolecules of Life Cell – The Basic Unit of Life 2 Biomolecules of Life and Cellular Transport 3 Core Idea 3 Energy and Equilibrium Transformation of Energy – Photosynthesis and Cellular Respiration 4 Core Idea 2 Genetics and Inheritance Genetics and Inheritance (I) – The Cell Cycle 5 Genetics and Inheritance (II) – DNA Replication and Gene Expression 6 Genetics and Inheritance (III) – DNA Mutations and their Consequences 7 Genetics and Inheritance (IV) – Molecular Techniques in DNA Analysis 8 Genetics and Inheritance (V) – Organization of Genome & Control of Gene Expression in Eukaryotes [Includes Core Idea 1D: Stem Cells] 9 Genetics and Inheritance (VI) – Organization and Inheritance of Viral Genomes 10 Genetics and Inheritance (VII) – Organization of Genome & Control of Gene Expression in Prokaryotes 11 Genetics and Inheritance (VIII) - Inheritance 12 Core Idea 3 Energy and Equilibrium Communication and Equilibrium in Multicellular Organisms 13 Core Idea 4 Biological Evolution Biological Evolution 14 Extension Topic A Infectious Diseases Immunity and Infectious Diseases 15 Extension Topic B Impact of Climate Change on Animals & Plants Climate Change – Causes and Impacts on Animals and Plants

Page 2 of 30 What’s the Big Picture? The following question should help students frame their learning: • How do organisms respond to internal and external changes? Communication is needed for organisms to respond to the environment and maintain equilibrium Organisms should be able to detect changes both from the surrounding environment and within themselves so that they are able to respond to these changes to maintain a constant internal environment. This ability to respond to changes is made possible due to coordination across the various biological systems as well as communication between cells. Communication between cells can take the form of electrical or chemical transmission via the nervous or endocrine system respectively. The endocrine system facilitates communication between different cells through the release of hormones into the bloodstream. Binding of hormones to receptors on or within target cells initiates signal transduction and eventually results in a change in gene expression to bring about certain physiological changes. Defects in any part of the signalling pathway often lead to detrimental conditions such as metabolic diseases and cancer. Core Idea 3: Energy and Equilibrium Topic B: Communication and Equilibrium in Organisms The emphasis of this section is on how cell signalling processes can cause a physiological response in an organism. The circulatory system transports hormones from where they are secreted to the target