Chapter 3: Biomolecules of Food 

^^Why do we need food?^^ - Energy, growth and repair of new cells, defense and reproduction.

  • Define Nutrition: the way in which an organism obtains and uses food.

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<<Carbohydrates<<<<Proteins<<<<Lipids<<
Elements present:CHO - Carbon, Hydrogen, OxygenCHON - Carbon, Hydrogen, Oxygen, NitrogenCHO - Carbon, Hydrogen, Oxygen
Structure^^Monosaccharides:^^ single sugar unit that soluble in water. Sources: fruit and vegetables.E.g. glucose and fructose.^^Disaccharides:^^ two mono. sugar units joined together that’s soluble in water. Sources: fruit and table sugar.E.g. sucrose and lactose^^Polysaccharides__:^^ __many mono. sugar units joined together that’s insoluble in water.Sources: bread, rice, pasta.E.g. cellulose, starch, glycogen.^^Proteins are made up of amino acids.^^ There are 20 different amino acids that determine the protein’s shape and function. A polypeptide is made up of 20 amino acids. A protein is made up of over 200 amino acids that are joined together by peptide bonds. They’re folded which determines their function.^^There are two different structures a lipid can be:^^ ^^Triglyceride:^^ - One glycerol molecule and 3 fatty acids. OR ^^Phospholipid:^^- One glycerol molecule, one phosphate head and 2 fatty acids. ^^Sources:^^ butter, margarine and milk.
Structural Role^^Plants:^^ cellulose is used in the plant cell wall which provides support and prevents bursting.^^Animals^^: chitin is found in the insect exoskeleton and in the fungal cell wall.^^Keratin^^ is the structural protein in our hair and nails. ^^Myosin^^ is the protein found in the cardiac and skeletal muscles.^^Collagen^^ is the structural protein for our skin- Store and supply of energy.- Insulates the body and protects the organs.- Forms membranes in cells (phospholipids)
Metabolic Role^^Plants^^: glucose is made in photosynthesis and stored as starch.^^Animals^^: glucose is broken down in respiration to release energy.^^Enzymes^^ control reactions in our body.^^Hormones^^ regulate body reactions.^^Antibodies^^ are made from proteins and are used to help fight infection.Lipids are ^^broken down in respiration^^ to release energy

\ ^^Define anabolic reactions^^: uses energy to build up a simpler molecule into a complex molecule. e.g. photosynthesis.

^^Define catabolic reactions^^: uses energy to break down a complex molecule into a simpler molecule. e.g. respiration.

\ ^^Define Vitamin:^^ organic compound needed in small amounts for proper body functioning (cannot be produced by the body)

^^Water Soluble Vitamin: Vitamin C^^^^Fat Soluble Vitamin: Vitamin D^^
Benefits: forms connective tissue in our skin and gums.Benefits: helps absorb calcium that is needed for bone and teeth formation.
Effects of deficiency: scurvy - bad teeth and gums.Effects of deficiency: rickets in children, osteomalacia in adults. (weak and brittle bones)

\ ^^Define Minerals^^: insoluble organic salts that contain elements that are needed for the metabolism in small amounts.

^^Plants^^^^Animals^^
Mg (Magnesium): helps make chlorophyll. Ca (Calcium): helps the cell walls attach to each other.Fe (Iron): used to make hemoglobin in the blood.Ca (Calcium): for bone + teeth formation.

\ ^^Why is water important?^^

  1. Good Solvent.
  2. Controls metabolic reactions: respiration, photosynthesis, digestion.
  3. Controls cell shape via osmosis.

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^^What was used?^^^^Positive Result^^^^Negative Result^^^^Heat Needed?^^
Testing for GlucoseBenedict’s SolutionBlue-black colorBrick RedYes
Testing StarchIodineBlue-black colorYellow-brownNo
Testing ProteinBiuret SolutionPurpleBlueNo
Testing for FatsBrown PaperTranslucent StainNon-translucent stain.No

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