LESSON 3

• The human body is composed of roughly 30 trillion

  cells that collectively perform the essential

  functions of life.
• Biomolecule refers any of numerous substances that are produced

  by cells and living organisms.
• The building block of carbohydrates called monosaccrhrides
• The building block of proteins called amino acids
• The building block of nucleic acid called nucleotides
• The building block of lipids are called fatty acids
• Carbohydrates are the most

  abundant biomolecules on earth.
• Carbohydrates are a vital part of a healthy diet.

  They provide the energy required to

  do work.
• 3 TYPES OF CARBOHYDTARES

  • Monosaccharides
  • Disaccharides
  • Polysaccharides
• Monosaccharides are simple sugars, the most common of which is glucose.
• Monosaccharides are colorless,

  crystalline solids that are completely soluble in water.

  They are involved in generating energy for the body.
• Examples of monosaccharides include glucose, galactose and fructose
• Disaccharides form when two monosaccharides undergo a

  dehydration reaction.
• During the process of dehydration reaction, the hydroxyl group (–OH) of one

  monosaccharide combines with a hydrogen atom of

  another monosaccharide, releasing a molecule of

  water (H2O) and forming a covalent bond between

  atoms in the two sugar molecules.
• The examples of polysaccharides includues starch, glycogen, cellulose, and chitin
• Lipids are molecules that contain hydrocarbons and make

  up the building blocks of the structure and function

  of living cells.
• 6 Classes of Lipids

  1. Fatty acids
  2. Waxes
  3. Phospholipids
  4. Glycolipids
  5. Steroids
  6. Eicosanoids
• Fatty acids These are the simplest forms of lipids. They are composed of

  hydrocarbon chains of 4-36 carbons and one acidic group.
• Waxes These are esters of fatty acids and long-chain alcohols. They are

  composed of hydrocarbon chains of 14-36 carbons.
• Glycolipids These are lipids containing saccharide groups. They are

  constituents of the cell membrane and are involved in signal

  transductions.
• Steroids These are complex derivatives of triterpenes.
• Eicosanoids They arise from the 20 carbons of polyunsaturated fatty

  acids.
• Nucleic acid are the biopolymers, or large biomolecules,

  essential to all known forms of life.
• 2 Types of Nucleic Acids

  1. Deoxyribonucleic acids
  2. Ribonucleic acids
• Deoxyribonucleic acids The double helix structure represents two polynucleotides DNA

  coiled around a central helix.
• Ribonucleic acids is mostly involved in protein synthesis. Structurally, -----

  exists in both single-stranded (primary structure) and

  double-stranded (secondary structure) forms.
• Proteins are formed by linking various amino acids.
• Primary structure It is formed by the formation of a peptide bond between

  amino acids.
• Secondary structure It is a folded structure within a polypeptide that’s due

  to the formation of hydrogen bonds between amide hydrogen and the carbonyl oxygen of the peptide backbone. It includes structures like alpha-helix and

  beta-sheet.
• Tertiary structure It is a three-dimensional conformation that’s formed due to the interaction between R-groups or side chains of the amino acids that make up

  the proteins.
• Quaternary structure This structure forms between two or more polypeptide

  chains. Each polypeptide chain is called a subunit.
• Amino acids are the monomers that make up proteins.
• Structural proteins These proteins are fibrous proteins that are tough and insoluble in

  water.
• Enzymes These are globular conjugated proteins that are also known as biological catalysts.
• Hormones These are long polypeptides composed of long chains of linked amino acids.
• Respiratory pigments These are globular protein pigments that are usually soluble in water.
• Transport proteins These are structural components of the cell membrane.
• Motor proteins These proteins are involved in the contraction and relaxation of the muscle (muscle movement).
• Storage proteins These proteins are the storage reserve of amino acids and metal ions in cells.
• Toxins These proteins are generally produced by bacteria.