Biology Ch. 2.5

  1. Organic molecules
    • chemical compounds that contain both carbon and hydrogen
    • Example-CH4 methane
  2. Monomers
    A single link in a polymeric molecule
  3. Polymer
    A long molecule composed of similiar subunits (monomers)
  4. dehydration synethesis/condensation
    • A protein called an enzyme removes an OH (hydroxyl group) from one molecule and a hydrogen atom from another, forming H2O and a new bond between the two smaller components.
    • units are linked to one another
  5. Hydrolysis/cleavage
    • When units are removed
    • When enzymes use atoms from water to add a hydroxyl group to one molecule and a hydrogen atom to another
  6. Carbohydrates
    • All composed of CHO in a 1:2:1 ratio
    • Simplest in structure of the four organic molecules of life
    • 2 groups- simple sugars and complex carbohydrates
  7. Monosaccharides
    • Single unit of a carbohydrate
    • Contains 5-6 carbon atoms (pentoses, hexoses)
    • Examples-glucose, galactose, fructose-->have the same # of carbons, but differ in # of atoms are bonded together (differ in taste, consistency)
  8. Disaccaride
    • 2 monosaccharides joined by dehydration synthesis
    • May be the same or different monosaccharides linked together
    • Simple carbohydrate-Both mono. and di. serve as sources of energy for cells
    • Example-sucrose, lactose
  9. Oligosaccharides
    • 3-100 monomers linked together to make carbohydrates
    • Attached to proteins embedded at/on cell surfaces
    • Include the ABO blood group antigens as well as the Rh factor in Red blood cells
    • Blood type is how these molecules are recognized- don't usually have names
  10. Complex carbohydrates or Polysaccarides
    • More than 100 monomers linked together
    • Most common polysaccharides-cellulose, chitin, starch, and glycogen
  11. Cellulose
    • Plant cell walls, cotton, wood, paper
    • Humans cannot digest cellulose
    • AKA fiber
  12. Chitin
    • exoskeletons of insects, crustaceans, fungal cell walls
    • Tough, flexible, and biodegradable
  13. Glycogen and starch
    • Stored forms of glucose and energy in heterotrophs and autotrophs
    • Differ in orientation of connecting bonds
    • Plant cells use starch
    • Animal and fungal cells use glycogen
  14. Lipids
    • Hydrophobic (don't mix with water)
    • Not usually polymers- varied chemical structures
    • Includes tryglycerides (veg. oil), sterols, waxes, and phospholipids
    • Necessary to life, stored form of energy, brain development during early age
    • Stored in adipose tissue, provides insulation, protection, cushioning
  15. Triglycerides
    A lipid consisting of one glycerol bonded to three fatty acids
  16. Three hydrocarbon chains attached to a glycerol via dehydration synthesis
    • 16-18 hydrocarbon chains are most common
    • 3 fatty acids are bonded to 1 glycerol
  17. carboxyl group
    A carbon atom double-bonded to one oxygen and single-bonded to another oxygen carrying a hydrogen atom (COOH)
  18. Saturated fats
    • The hydrocarbon chains are the most common
    • Things that are solid at room temp. (butter, lard)
    • Has all the hydrogens it possibly can
    • Saturated fats clog arteries, which is why it should be avoided.
  19. Unsaturated fats
    • Hydrocarbon chains contain one or more double bonds
    • Liquid at room temp.- plant fats, veg. oil
    • )
  20. Hydrogenation
    • Addition of hydrogen to unsaturated fats to solidify them
    • Results in formation of trans fats-->worse than saturated fats!
  21. Sterols
    • composed of 4 carbon rings
    • Include cholesterol, Vitamin A,D,E,K, cortisone, and precursors of estrogen and testosterone
  22. Waxes
    • Fatty acid chains attached to alcohols or hydrocarbons
    • Most are stiff/solid
    • Water repellent coatings on animals, fruit/veg., and ear wax
  23. Phospholipids
    • Major component of cell membranes
    • 2 hydrocarbon chains (hydrophobic) amd a phosphate group attached to a glycerol
  24. Proteins
    • Chains of monomers called amino acids
    • Huge diversity in function (hormones, enzymes, antibodies)
  25. Amino acids
    • what makes up protein
    • 20 amino acids are commonly used, all w/ same basic structure
    • Has a central atom and
    • A hydrogen aton, carboxyl group (acid), and amino group (NH2), and a R group
    • (remainder of the molecule)
    • Dehydration synthsis links amino acids together
    • Vary by their R groups-may be simple or complex
  26. 8 amino acids essential to humans
    • Tryptophan
    • Lysine
    • Methionine
    • Valine
    • Leucine
    • Isoleucine
    • Threonine
    • Phenylalanine
  27. Peptide bond
    The covalent bond that links the carbon from the carboxylic acid group of one amino acid to the nitrogen of the other
  28. Polypeptides
    • Chains with 100 or more amino acids
    • When it is in its functional shape, it is called a protein
  29. Secondary structure
    • When hydrogen bonds form between amino acid carboxyl groups of nonadjacent amino acids
    • Results in formation of beta pleated sheets and alpha helices (coils)
    • telephone cord
  30. Peptides
    Lss than 100 amino acids
  31. Primary Structure
    • Determined by DNA
    • Covalent bonds form between amino acids during protein synthesis (translation)
    • Soluble in water
    • Amino acid sequence
    • Beads on a chain
  32. Tertiary structure
    • Due to "R" gorup interactions, ionic attractions, disulfide bonds
    • Hydrophobic sections are forced to the middle of the protein, hydrophillic portions are to the outside
    • 1 blob
  33. Quaternary Structure
    • 2 or more polypeptide chains are folded together
    • Examples- Hemoglobin, antibodies, some membrane signal proteins
    • Lots of blobs
  34. Denaturation
    • Unfolding and breaking of bonds/interactions between amino acids
    • increase in temperature, changes in pH, salts, and detergents may result in this
    • Cooking an egg, curling hair
  35. Nucleic acids
    • Hereditary material of cells
    • DNA-deoxyribonucleic acid
    • RNA-ribonucleic acid
    • Composed of monomers called nucleotides
  36. Nucleotides
    Contains a 5 carbon sugar (pentose), nitrogen base and a phosphate group
  37. DNA
    • double stranded polymers shaped as a double helix, liked together by H bonds
    • Has Adenine (A), guanine (G), Thymine (T), and Cytosine (C)
  38. RNA
    • Single stranded polymer
    • Has Adenine (A), guanine (G), Uracil (U), and Cytosine (C)
Card Set
Biology Ch. 2.5
Chapters 2.5