1.3 Common Substances Essential to Living Things

Overview Essential elements for living things Nutrients (macro vs. micro) Types of nutrients Organic vs. inorganic elements Types of organic elements - what they are, and which foods they are in: Carbohydrates Lipids Proteins and amino acids Nucleic acids Optimum amounts of nutrients, and nutrient deficiencies

Essential Elements Our bodies require 25 different elements for normal growth The most common are carbon, hydrogen, and oxygen These form sugars, starch, fat, oil, wax, and proteins

Nutrients Elements and compounds that organisms need in order to live, grow, and reproduce Macronutrients: Nutrients needed in large amounts e.g. C, H, O, N, P, K, Mg, Ca, S Micronutrients: Nutrients need in smaller or trace amounts e.g. Se By knowing the roles elements play for living things, we can diagnose nutrient deficiencies

Types of Nutrients

Organic and Inorganic Elements Organic molecules contain carbon whereas inorganic do not The main types of organic molecules used by living things are: Carbohydrates Lipids Proteins and amino acids Nucleic acids

Carbohydrates Made up of C, H, and O Also called sugars (You don’t need to know these structures! They are just to illustrate the difference between simple and complex carbohydrates) Carbohydrates Made up of C, H, and O Also called sugars Can be simple (e.g. glucose) or complex (e.g. starch, glycogen, cellulose) Note: complex carbohydrates are ‘complex’ because they contain many simple carbohydrate molecules that are bonded to one another! Glucose Glycogen Produced by plants during photosynthesis Stored in cells of living organisms Broken down to provide energy for chemical processes in the body Found in: Pasta, rice, fruits, and bread

Lipids Oils, fats, and waxes Made up of mostly carbon, also include oxygen and hydrogen Produced by animals (e.g. the oil produced by the skin), and plants The food that we eat is stored long-term in the form of fat Found in: Canola seeds, nuts, soybeans, avocados

Amino Acid Proteins and Amino Acids Protein Used by organisms for growth and repair Source of energy Main component of enzymes Protein Proteins are made up of amino acids Amino acids contain N, H, C, and O atoms, and sometimes S The way that amino acids join together to form proteins is similar to how glucose molecules form to create complex carbohydrates such as glycogen Found in: Meat, fish, eggs, dairy products

Nucleic Acids The largest and most complicated molecules found in living things Found in the nuclei of cells The two important ones are DNA and RNA These play important roles in heredity and controlling cell activities Nucleic acids are made up of phosphates, ribose (a simple sugar), and nitrogen-containing molecules

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Optimum Amounts The amount of a substance that provides an organism with the best health If plants and animals are not receiving optimum amounts of a nutrient many things may occur, such as: Growth Illness Presence of disease