Enzymes, Lipids & Carbohydrates

• Organic compounds are molecules that contain carbon and are usually bonded with hydrogen and other elements like oxygen, nitrogen, and phosphorus.
• Organic compounds are essential for life and are more complex compared to inorganic compounds.
• Carbohydrates, lipids, protein, enzymes, vitamins and nucleic acids (DNA and RNA) are examples of organic compounds.

Carbohydrates

• Elements: Carbon, hydrogen, and oxygen
• Hydrogen to oxygen ratio: 2:1
• Monomer (building blocks): Saccharides (Greek: sugar)
• The name carbohydrate suggests carbon and water, meaning it follows the general formula C(H2O).
• Monosaccharides are single sugars, with examples including glucose and fructose.
• Disaccharides are double sugars, with examples including maltose and sucrose.
• Polysaccharides consist of many linked sugars, with examples including starch, cellulose, and glycogen.
• Monosaccharides and disaccharides are found in fruits and vegetables.
• Polysaccharides are found in bread, rice, flour, pasta, and potatoes.
• Provides energy for plants and animals.
• Plants store carbohydrates as starch.
• Animals store carbohydrates as glycogen.
• Cellulose forms cell walls.

Lipids: Cholesterol

• Cholesterol is a lipid found in the human body and is sourced from both diet and liver production.
• A component of cell membranes
• Needed to produce vitamin D.
• Excess cholesterol can deposit on blood vessel walls, leading to atherosclerosis (narrowing of blood vessels.)
• If a blockage occurs in a vessel supplying the heart, it can result in a heart attack.
• HDL (High-density lipoprotein) is good cholesterol, which is beneficial to the body.
• LDL (Low-density lipoprotein) is bad cholesterol, which is harmful in high amounts.
• Risk factors for high cholesterol are diet high in saturated fats, obesity, lack of exercise, genetics, and aging.
• Fruits and vegetables don't contain cholesterol.
• Examples: Fats, oils, steroids, cholesterol.
• Composition: Carbon, hydrogen, an oxygen; the H:O ratio is greater than 2:1.
• Formed when one glycerol combines with three fatty acids.

Types of Fatty Acids

• Saturated fats have single bonds in the fatty acid chains and are solid at room temperature.
• Unsaturated fats have one or more double bonds in the fatty acid chains and are liquid at room temperature.
• Animal source: Butter, fatty meats, sardines.
• Plant source: Oils, nuts.
• Energy Source: Provides twice the energy compared to carbohydrates.
• Insulation: Fat (blubber) under the skin prevents heat loss in animals.
• Most plants store oils in their seeds.

Protein: Enzymes

• Enzymes are complex protein molecules that act as biological catalysts, speeding up biochemical reactions in living organisms without being used up in the process.
• Involved in both anabolic reactions (building new molecules) and catabolic reactions (breaking down molecules.)
• Enzymes play a crucial role in processes such as photosynthesis, cellular respiration, and digestion of food in animals.
• Examples: Albumen, enzymes, haemoglobin.
• Composition: Carbon, hydrogen, oxygen and nitrogen.
• Some proteins may contain sulfur, phosphorus or iron.
• High temperatures denature proteins, causing them to lose their shape and function.
• Low temperatures render enzymes inactive.
• Enzymes are highly specific; the catalyze due to the specific reactions, because of their unique shape.
• Animal sources: Fish, meat, eggs.
• Plant sources: Nuts, beans.
• Growth and repair of body tissues.
• Enzymes are proteins that speed up chemical reactions.
• Hormones are proteins that act as chemical messengers in the blood.
• Haemoglobin is a protein in the blood that transports oxygen and carbon dioxide.
• The enzyme has a specific active site that matches the shape of its substrate.
• When the substrate binds to the enzyme, an enzyme-substrate complex is formed
• The substrate undergoes a process or chemical reaction, either breaking down or rearranging into new products.
• The products are released, and the enzyme remains unchanged and freeto act on another substrate.
• Biological washing powders contain protease to break down protein stains like blood and egg.
• Enzymes help in processing animal hides during leather production.
• Enzymes aid in the beer-making process in the brewing industry.

Nucleic Acids

• Nucleic acids are made of carbon, hydrogen, oxygen, nitrogen, and phosphorus.
• Nucleotides are monomers of nucleic acids.
• Types: DNA (deoxyribonucleic acids) and RNA (ribonucleic acid).

DNA

• Located in chromosomes.
• Stores genetic information and helps in protein synthesis.
• Has a double helix structure (two strands.).
• Components include a phosphate group (P), deoxyribose sugar (S) - a pentose sugar, and a nitrogenous base (NB).
• Four types of nitrogenous bases: adenine (A), thymine (T), guanine (G), and cytosine (C).

Vitamins

• Organic compounds are needed in small amounts for growth.
• A deficiency disease occurs when a vitamin is lacking in the diet.
• Water-soluble vitamins: Example - Vitamin B complex and Vitamin C.
• Are not stored in the body and are flushed out with urine.
• Need be consumed regularly
• Fat-soluble vitamins: Example - Vitamins A, D, E.
• Stored in body fat.
• Do not need to be consumed as frequently.

Tests

Carbohydrates

• Starch (Polysaccharide) Test
  • The starch test uses iodine solution to show the presence of starch.
  • Positive: Blue-black color
  • Negative: Yellow-orange color
• Glucose Test
  • Fehlings A and B test
    • Positive: Green, yellow, orange, red color
    • Negative: Blue color
  • Benedict’s Test
    • Positive: Brick red colour
    • Negative: Blue colour
• Lipid Test
  • Emulsion Test.
    • First the sample is mixed with ethonal to dissolve any lipids.
    • Then water is added to the solution.
      • Positive: Lipids are present, they will form a milky emulsion as the water & ethanol mix.
      • this cloudiness is because lipids are insoluble in water causing them to scatter light and create a milky appearance.
• Protein Test
  • Millons reagent Test
    • Positive: Wine red colour
    • Negative: White / Cream colour
  • Biuret Test
    • Positive: Violet to Purple colour
    • Negative: Blue Colour
• The test detects peptide bonds (make protein).
• Biuret reagent contains copper which reacts with proteins in alkaline solution.

Test your knowledge of enzymes, lipids, and carbohydrates. This quiz covers enzyme function, lipid health implications, carbohydrate structures, and related concepts in biochemistry. Questions explore enzyme mechanisms, lipid types, carbohydrate storage, and health risks associated with these biomolecules.