1 / 27

Biological Molecules

Biological Molecules. Biological Molecules. Life is carbon-based chemistry Hydrolysis and Synthesis of Biological Molecules Carbohydrates Lipids Proteins Nucleic Acids. Life is carbon-based chemistry.

Download Presentation

Biological Molecules

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Biological Molecules

  2. Biological Molecules • Life is carbon-based chemistry • Hydrolysis and Synthesis of Biological Molecules • Carbohydrates • Lipids • Proteins • Nucleic Acids

  3. Life is carbon-based chemistry • Organic is used to describe molecules that have a carbon skeleton and some additional hydrogen atoms • Life is composed of organic molecules • Inorganic molecules include carbon dioxide, water and all other non-carbon molecules

  4. Life is carbon-based chemistry • The tremendous diversity of organic molecules is due to the diverse functional groups that attach themselves to common carbon skeletons: • Hydrogen (-H) • Hydroxyl (-OH) • Carboxyl (-COOH) • Amino (-NH2) • Phosphate (-H2PO4) • Methyl (-CH3)

  5. Hydrolysis and Synthesis of Biological Molecules • Small organic molecules are used as subunits to synthesize longer molecules • The individual subunits are called monomers • The longer molecules are called polymers

  6. Hydrolysis and Synthesis of Biological Molecules • Monomers are linked to monomers in a chemical process called dehydration synthesis • The –H group is removed from one monomer and the –OH group is removed from the second monomer • The two monomers join by forming a covalent bond • The –H group and –OH group bond to form a water molecule

  7. Hydrolysis and Synthesis of Biological Molecules • Polymers are disassembled into monomers through a process called hydrolysis • The polymer splits into monomers • A water molecule splits and releases a –H group and a –OH group • The –H group and –OH group bond to the monomers to complete their structure

  8. Carbohydrates • Contain carbon, hydrogen and oxygen in the constant ratio of 1:2:1 • Carbohydrates are “hydrates of carbon” • C1H201 or CH20 • All carbohydrates are either small, simple sugars or polymers of these simple sugars

  9. Carbohydrates

  10. Lipids • Lipids contain large regions of H and C atoms joined by non-polar covalent bonds • Non-polar regions are hydrophobic • Lipids are not soluble in water • Three major groups of lipids • (1) oils, fats and waxes • (2) phospholipids • (3) steroids

  11. Oils, Fat and Waxes • Contain only C, H and O atoms • Composed of one or more fatty acids subunits attached to a glycerol subunit • Are straight chains: do not have ring structures • Function as source of energy

  12. Oils, Fat and Waxes • Fatty acid chains that have no C=C double bonds are said to be saturated with H atoms • Fatty acid chains that have C=C double bonds are said to be unsaturated with H atoms • Saturated fatty acid chains are straight • Unsaturated fatty acid chains are kinked

  13. Oils, Fat and Waxes • Oils are liquid at room temperature because they are unsaturated → kinks • Waxes are solid at room temperature because they are saturated → straight

  14. Phospholipids • Similar to structure of fats, waxes and oils except one of the three fatty acid chains is replaced by a phosphate group containing a polar functional group • The two fatty acid chains are hydrophobic • The phosphate head (being polar) is hydrophilic • Function as basic component of membranes

  15. Steroids • Composed of four rings of carbon fused with various functional groups • Steroids are synthesized from cholesterol • Function as hormones and components of animal cell membranes

  16. Proteins • Proteins are polymers of amino acid subunits • The bond between amino acid subunits is called a peptide bond (formed by dehydration synthesis) • Diversity of proteins is due to diversity of amino acids and the diverse ways amino acids arrange themselves • Proteins function as enzymes, structural components, transport proteins, energy storage, cross-membrane transport, and hormones

  17. Proteins • Amino acids are composed of a central C atom bonded to four different functional groups: • (1) amino group (-NH2) • (2) carboxylic acid group (-COOH) • (3) hydrogen group (-H) • (4) variable group (-R)

  18. Proteins • The –R group creates the diversity of amino acids • Some -R groups are small, others large • Some –R groups are hydrophobic, others hydrophilic • The type of –R group directly affects the structure of the protein

  19. Proteins • Proteins have four levels of structure • (1) Primary Structure: sequence of amino acids in the linear protein polymer • (2) Secondary Structure: simple repeating pattern created by hydrogen bonding between amino acid subunits • Secondary structure can be either a helix or pleated sheet

  20. Proteins • (3) Tertiary Structure: complex 3 dimensional shape formed by folding over of secondary structure • Tertiary structure is due to disulfide bridging between neighbouring cysteine amino acids; size of –R group; hydrophobic/hydrophilic interactions

  21. Proteins • (4) Quaternary Structure: due to joining together of smaller proteins in order to form a larger protein complex

  22. Nucleic Acids • Nucleic acids are polymers of nucleotide subunits • Nucleotides are composed of three components themselves: • (1) a five C sugar (ribose/deoxyribose) • (2) a phosphate group • (3) a N containing base

  23. Nucleic Acids • It is the diversity in N containing bases that creates diversity in nucleotides • It is the diversity in sugars that adds to the diversity of nucleic acids

  24. Nucleotides

  25. Nucleic Acids • Nucleic acids function primarily as the molecules of heredity and the blueprint for protein synthesis (DNA and RNA) • Nucleic acids also act as intracellular messengers (cAMP), coenzymes and energy carrier molecules (ATP)

More Related