Organic Compounds: Carbohydrates and Lipids

• Organic compounds are molecules containing carbon, often bonded with hydrogen and other elements like oxygen, nitrogen, and phosphorus.
• Organic compounds are essential for life and more structurally complex versus inorganic compounds.

Examples of Organic Compounds

• Carbohydrates
• Lipids
• Proteins
• Enzymes
• Vitamins
• Nucleic acids (DNA & RNA)

Carbohydrates

• Carbohydrates contain carbon, hydrogen, and oxygen.
• The ratio of hydrogen to oxygen in carbohydrates is 2:1.
• The monomer building blocks of carbohydrates are saccharides (Greek for sugar).

Lipids: Cholesterol

• Cholesterol is a lipid found in the human body.
• Cholesterol is sourced from both diet and liver production.

Functions of Cholesterol

• Component of cell membranes.
• Needed to produce vitamin D.

Health Effects of Cholesterol

• Excess cholesterol can deposit on blood vessel walls, leading to atherosclerosis (narrowing of blood vessels).
• A blockage in a vessel supplying the heart can result in a heart attack.

Types of Cholesterol

• HDL (High-Density Lipoprotein) is considered good cholesterol, which is beneficial to the body.
• LDL (Low-Density Lipoprotein) is considered bad cholesterol, which is harmful in high amounts.

Risk Factors for High Cholesterol

• Diet high in saturated fats
• Obesity
• Lack of exercise
• Genetics
• Aging
• Fruits and vegetables do not contain cholesterol

Protein: Enzymes

• Enzymes play a role in metabolism.
• Enzymes are complex protein molecules acting as biological catalysts, speeding up biochemical reactions in living organisms without being used up in the process.
• Enzymes involved in both anabolic (building new molecules) and catabolic (breaking down molecules) reactions.
• Enzymes play a crucial role in processes such as photosynthesis and cellular respiration
• Enzymes play a crucial role in the digestion of food in animals.

The Lock and Key Theory of Enzyme Action

• An enzyme has a specific active site that matches the shape of its substrate.
• A substrate binds to the enzyme, an enzyme-substrate complex is formed.
• A substrate undergoes a chemical reaction, either breaking down or rearranging into new products.
• The products are released, and the enzyme remains unchanged/free to act on another substrate.

Industrial Uses of Enzymes

• Biological washing powders contain protease breaking down protein stains like blood, egg, etc
• Leather production processes use enzymes.
• Brewing industry uses enzymes in the beer-making process.

Carbohydrates Composition

• Carbohydrates contain carbon (C), hydrogen (H), and oxygen (O).
• Carbohydrate name implies carbon and water, following the general formula C(H2O).

The 3 Groups of Carbohydrates

• Monosaccharides: single sugars (e.g., glucose, fructose)
• Disaccharides: double sugars (e.g., maltose, sucrose)
• Polysaccharides: many linked sugars (e.g., starch, cellulose, glycogen)

Source of Carbohydrates

• Monosaccharides and disaccharides are found in fruits and vegetables.
• Polysaccharides are found in bread, rice, flour, pasta, and potatoes.

Function of Carbohydrates

• Provides energy for plants and animals.
• Plants store carbohydrates as starch,
• Animals store it as glycogen
• Cellulose forms cell walls.

Lipids

• Examples include fats, oils, steroids, and cholesterol.
• Lipids contain carbon, hydrogen & oxygen with the hydrogen/oxygen ratio > 2:1.
• Lipids form when 1 glycerol combines with 3 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.

Source of Lipids

• Animal sources include butter, fatty meats, and sardines.
• Plant sources include oils and nuts.

Function of Lipids

• Lipids provide twice the energy compared to carbohydrates.
• Fat is an insulator (e.g., blubber under the skin) and prevents heat loss in animals.
• Most plants store oils in their seeds.

Protein

• Examples include albumen, enzymes, and hemoglobin.
• Proteins are made of carbon, hydrogen, oxygen, and nitrogen; some contain sulfur or phosphorus or iron.

Properties of Proteins

• High temperatures denature proteins causing losing shape and function.
• Low temperatures render enzymes inactive.
• Enzymes are highly specific and reactions are catalyzed due to their unique shape.

Source of Proteins

• Animal sources include fish, meat and eggs.
• Plant sources include nuts and beans.

Function of Proteins

• Needed for growth and repair of body tissues.
• Enzymes speed up chemical reactions.
• Hormones are proteins acting as chemical messengers in the blood.
• Hemoglobin is a protein in the blood that transports oxygen and carbon dioxide.

Nucleic Acids

• Nucleic acids are comprised of carbon, hydrogen, oxygen, nitrogen, and phosphorus.
• The monomers of nucleic acids are nucleotides.

Types of Nucleic acids

• DNA (Deoxyribonucleic acid)
• RNA (Ribonucleic acid)

DNA

• DNA is found in chromosomes.
• DNA stores genetic information and helps in protein synthesis.
• DNA is a double helix (two strands).

Components of DNA

• Phosphate group (P)
• Deoxyribose sugar (S) - a pentose sugar
• Nitrogenous base (NB) - adenine (A), thymine (T), guanine (G), and cytosine (C)

Vitamins

• Organic compounds needed in small amounts for growth.
• Vitamin deficiency disease occurs when a vitamin is lacking in the diet.

Types of Vitamins

• Water-soluble vitamins (e.g., Vitamin B complex, Vitamin C) are not stored in the body and flushed out with urine, so they need to be consumed regularly.
• Fat-soluble vitamins (e.g., Vitamins A, D, E) are stored in body fat and do not need to be consumed as frequently.

Carbohydrates test

• The starch test uses iodine solution to show presence of starch
• If starch presence: Blue–black colour
• If starch absent: Yellow-orange colour

Glucose Test

• The Fehlings A and B test will react to monosacharides
• If monosacharides are more than 0.5%: Green, Yellow, Orange , Red colour
• If monosacharides aren't more than 0.5%: Blue colour
• The Benedict's test will test for monosacharides
• If present : Brick red colour
• If absent: Blue colour

Tests for lipids

• The emulsion test will test for fats
• First the sample is mixed with ethanol to dissolve any lipids present, then water is added to the solution
• If: Lipids are present- They will form a milky emulsion as the ethanol and water mixture
  • This cloudiness is because lipids are insoluble in water, causing them to scatter light and create a milky appearance

Tests for proteins

• Millons reagent
• Positive color: Wine red Colour
• Negative color: White/Cream colour
• Biuret
• Positive color: Vioiel to Purple Colour
• Negative color: Blue colour
• Detects the making of peptide bonds

Overview of organic compounds, focusing on carbohydrates and lipids such as cholesterol. This includes the chemical composition and functions of carbohydrates and the health effects of cholesterol.