Chemical basis of Life

• Biochemistry - study of chemical processes within the living organisms
• organic compounds

  • contain carbon
  • life on Earth said to be 'carbon-based' because organism contain organic compounds
• Biomolecules - found in living organisms
• Carbohydrates

  • composed of carbon, hydrogen, and oxygen
  • also known as saccharides/sugar
  • provide & store energy
  • structure & support to organisms
• Monosaccharides - simple sugars
• Disaccharides - two monosaccharides joined together by glycosidic bond
• Polysaccharides - many monosaccharides joined together by glycosidic bonds
• Lipids

  • compound with fatty acid-glycerol
  • relatively insoluble in water, but soluble in nonpolar solvents
  • store energy
  • structural components of membranes
  • provide insulation
  • main components of most hormones and vitamins
• Fatty acids - bound together by glycerol
• Fats - lipids that are solid at room temperature and obtained from animal sources
• Oils - lipids that are liquid at room temperature and obtained by plants
• Proteins

  • long chains of amino acids
  • support, storage, transport, movement, etc.
  • function as enzymes
• Polypeptide - long chain of amino acids bonded by peptide bonds
• Enzymes

  • biological catalysts that are usually proteins
  • initiate, speed up, or inhibit a metabolic process.
• Nucleic acids - made up of nucleotides
• Nucleotides - unit made up of nitrogenous bases, sugar, and phosphate backbone
• Nitrogenous bases - made up of Adenine (A), Guanine (G), Cytosine (C), Thymine (T), and Uracil (U)
• DNA/Deoxyribonucleic Acid is a double-stranded nucleic acid that carries genetic information in the form of genes

  • composed of A,T,C and G
  • double helxi configuration
  • 2 strands run anti-parallel to each other
• Base pairing - bases of 1 DNA strand pairing up with bases in another strand through Hydrogen Bonding
• RNA/ribonucleic acid is a single-stranded substance that has various roles. (A, U, C, G)
• Molecular biology

  • molecular basis of biological activity
  • concerned with the flow of genetic information within a biological system.
• DNA replication (blueprint)

  • synthesis of new DNA
  • nucleus & involves a semi-conservative process
  • new DNA is composed of an old strand and a new strand
• DNA helicase - unwinds the parent DNA into 2 strands at the replication fork becoming the templates
• Primase - signals the point where DNA synthesis will begin
• DNA polymerase

  • synthesizes the complementary strand
  • leading strand will be produced smoothly in the 5' to 3' direction
• Okazaki fragments - small sections of DNA that are formed during discontinuous synthesis of the lagging strand during DNA polymerase.
• DNA ligase - re-anneals the semi-conservative strands and joins the Okazaki fragments
• Transcription(instructions) - copying of a segment of DNA to mRNA
• Helicase - break hydrogen bonds between complementary DNA, forming a transcription bubble
• RNA polymerase - adds matching RNA nucleotides that are paired with complementary DNA nucleotides
• mRNA

  • the released from the nucleus into cytoplasm.
  • carries the sequence that will be translated to proteins
• Translation (building) - synthesis of a polypeptide by ribosomes under the direction of mRNA