Booklet 3: Molecules for life
Cells are the smallest units of all living things. Inside cells are molecules (water, glucose, protein). Any molecule is made of atoms. Cells carry out metabolic reactions in order to stay alive. Anabolic reactions- large molecules are built when small molecules join together. Catabolic reactions- large molecules break down to form smaller molecules. Organelles- basic components of cells
The different biological molecules in cells can be grouped into 2 types: ORGANIC and INORGANIC COMPOUNDS. Organic Compounds – contain carbon, linked with other elements such as, oxygen, hydrogen, nitrogen, sulphur, iron and phosphorous. Organic molecules are usually large molecules like sugars, starch, fats, proteins, vitamins & enzymes.
Inorganic Compounds – Usually never contain carbon but does contain Carbon Dioxide. Inorganic molecules such as water, mineral salts, and gases such as oxygen.
Inorganic Compounds are compounds that contain other elements. 1. WATER
Water most important inorganic molecule for living organisms. Main functions of water in living organisms:
* Solvent. Mineral salts dissolve in water allowing them to be absorbed by roots of plants. Carbon Dioxide and Oxygen must dissolve in water before they can enter and exit cells. * Chemical Reactions All chemical reactions in living organisms take place in water. * Transportation. Minerals transported in water to plants, and other substances are dissolved in water so can be transported around body in blood. * Reproduction. Sperm need water to swim to ova.
* Body shape. Plants rely on water for shape and structure. * Regulate Body Temp in plants and animals. Animals produce sweat to not overheat, plants, transpiration helps to cool plant.
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