Chem 32 ch. 14

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Chem 32 ch. 14
2011-11-25 03:34:15

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  1. What are monosacharides?
    Simple sugars.

    Monosacharides contain just C, H, and O, that's what makes them so simple. They always have a ratio of 1C, 2H, 1O. So for a 6 carbon sugar: C6H12O6
  2. How are sugars classified?
    • By the number of carbons in the sugar ( not just in the carbon ring itself but the whole molecule ).
    • 3 carbon Triose
    • 4 carbon Tetrose
    • 5 carbon Pentose
    • 6 carbon Hexose
  3. Four rules of simple sugars in our bodies.
    • They all contain a 5 or 6 atom ring/
    • One of the atoms in the ring is O, the rest C.
    • Any C atoms that aren't part of the ring but are attached to the ring are attached closest to the O in the ring.
    • Only one of the C atoms is not attached to a hydroxyl group ( OH ).
  4. What is a hemiacetal group?
    C-O-C-OH, on a sugar
  5. How do you know if a sugar is an aldose or ketose?
    When the sugar opens into a straight chain, it breaks at the hemiacetal group ( the bond between the O that's part of the ring itself and C1 or C2 breaks ) and the carbonyl group will either be a part of a ketone or an aldehyde.

    If a ketone is formed then the sugar is a ketose, if an aldehyde forms then the sugar is an aldose.
  6. What is a reducing sugar?
    If the sugar can reduce the charge on a Cu2+ ion.

    If in the open chain form the sugar forms an aldehyde O=C-H, then it can be easiyly oxidized to form a caboxylate ( ion form of carboxyl ) group O=C-O-. The copper gains an electron and reduces to Cu+.
  7. What are anomers?
    Anomers are sugars that are almost exactly the same except for which what the H and OH attached to the anomeric ( hense the name ) are pointed.

    If the H is pointed up it is an alpha glucose, if H is pointed down it is a beta glucose.
  8. What are enantiomers?
    An enantiomer of a glucose is the mirror image of that glucose. A mirror image of alpha D glucose is alpha L glucose. Same with beta D and beta L glucose.

    Our bodies like the D forms of carbohydrates best, we really don't use L glucose.
  9. What is a disacharide?
    A disacharide is two monosacharides bonded together.
  10. What are polysacharides?
    Long chains of monosacharides linked together.

    Storage polysacharides store energy.

    Structural polysacharides make up plant fibers and chitin, and other stuff.
  11. Starch is a storage polysacharide found in plants.

    What are two kinds of starch?
    Amylose and amylopectin.

    Amylose is straight, unbranched chain of glucose molecules.

    Amylopectin is a long chain of glucose molecules with chains of glucose attached every 25 - 30 molecules.
  12. What is amylase?
    An enzyme produced by our bodies that hydrolize the glycosidic linkage of starches and break them down into dextrins ( kind of smaller pieces of the starch molecule ) then another amylase breaks down the dextrins into glucose and maltose.
  13. What is glycogen?
    Animal starch. It is a polysacharide that is very large and has lots and lots of branches on it. It store energy for later use by breaking it down into glucose when the body needs it.
  14. What is structural polysacharides?
    Polysacharides that are used to build structure of plants or shells of... animals with shells.

    Cellulose and chitin are two kinds of structural polysacharides.

    Cellulose is fiber made up of long strands of polysacharides that lay flat against each other and bond very strongly with each other.
  15. What are lipids?
    Organic compounds that are made and used by living organisms and are not soluble in water.
  16. What are triglycerides?
    Triglycerides are compounds made from glycerol ( glycerin ) and fatty acids.

    Fatty acids are carboxylic acids with long, unbranched hydrocarbon chains.
  17. What is glycerol / glycerin?
    • CH2-OH
    • |
    • CH-OH
    • |
    • CH2-OH

    A triglyceride will have one of these with three fatty acids attached to it.
  18. What is a saturated fatty acid?
    A fatty acid with no alkene groups, no = double bonds.

    Saturated fatty acid = no alkenes.

    Think of it as being saturated with hydrogen, the lack of double bonds allows it to soak up more hydrogen.
  19. What is an unsaturated fatty acid?
    Fatty acids that do have at least one alkene = group, C=C double bond.

    Unsaturated fatty acid = at least one alkene.

    All commonly occuring unsaturated fatty acids have cis alkene groups.
  20. What are monounsaturated fatty acids?
    Fatty acids with only one alkene.
  21. What are polyunsaturated fatty acids?
    Fatty acids with more than one alkene.
  22. What is the omega carbon in a fatty acid?
    It is the final carbon in the carbon chain of the fatty acid. The first carbon being the one that is part of the carboxylic acid.
  23. How are polyunsaturated faty acids classified?
    Count the bonds between the omega carbon and the first alkene. So,

    CH3-CH-CH-C=C-CH... = omega-4 fatty acid
  24. Fatty acids and tryglicerides are insoluble in water.
    Fatty acids and tryglicerides are insoluble in water.
  25. The more alkene groups in a fatty acid, the -lower- its melting point.
    The more alkene groups in a fatty acid, the -lower- its melting point.
  26. Unsaturated fatty acids and triglycerides that are made of them have a melting point that is ___ than saturated fatty acids or triglycerides that are made of them.
    Lower. Unsaturated fatty acids have at least one C=C double bond and have higher melting points than saturated fatty acids or triglycerides made from them. The more alkenes the lower the melting point.

    Unsaturated fatty acids have a melting point below 15 C and are liquid at room temperature and in the body.

    Triglycerides made from 3 unsaturated fatty acids behave similarly to individual unsaturated fatty acids.
  27. Saturated fatty acids and triglycerides made from them have a melting point that is ___ than unsaturated fatty acids and triglycerides that are made from them.
    Higher. The more C-C single bonds a saturated fatty acid has, the higher its melting point will be and they will almost always have a higher melting point than unsaturated fatty acids.

    Saturated fatty acids melt at temperatures above body temperature ( 37 C ) so they remain as solids in the body.

    Triglycerides made from 3 saturated fatty acids behave similarly to individual saturated fatty acids.
  28. Most triglycerides are made from 3 different fatty acids and are called "mixed triglycerides".
    Most triglycerides are made from 3 different fatty acids and are called "mixed triglycerides".
  29. How to determine melting point of mixed triglycerides...
    If it is made up of at least 2 saturated fatty acids it is usually a solid at room temperature, like an individual saturated fatty acid.

    If it has fewer than two saturated fatty acids it will likely be a liquid at room temperature.
  30. Hydrogenation can turn unsaturated fatty acids into saturated fatty acids...
    Hydrogenation can change a C=C double bond into a CH2 and a CH2.

    So hydrogenated oil is saturated, think of it as being saturated with hydrogen. This is "partially hydrogenated". Now you know. :)

    In most cases only some of the double bonds are hydrogenated.
  31. Saturated fatty acids cannot react with oxygen and spoil.
    Saturated fatty acids cannot react with oxygen and spoil.
  32. What is a trans fatty acid ( trans fat )?
    Naturally occuring unsaturated fatty acids are cis, when exposed to a catalyst that hydrogenates them ( or most of them ) the alkenes that remain are trans.
  33. Triglycerides can be hydrolized...
    Triglycerides have ester groups ( O=C-O-C ) that can be hydrolyzed. The bond between the single bound O and one of the Cs will be broken.

    If a strong acid is used then the C-O bond closest to the carbonyl will be broken and OH added to the carbon so that it becomes a carboxylic acid.

    If a strong base is used the C-O bond furthest from the carbonyl group is broken and the O becomes ionized O- and attracts the metal Na, K that is positively ionized.

    In either case glycerin is also produced.
  34. What is lipase?
    Lipase is an enzyme in the digestive system that breaks down triglycerides into monoglycerides - glyceride with one single fatty acid attached.
  35. What is a monoglyceride?
    A triglyceride that has been broken down by lipase so that it is only a glyceride with a single fatty acid attached
  36. The membranes surrounding cells and the structures within cells are made of lipids.
    The lipids contain fatty acids and glycerol. They are not triglycerides but they are closely related to triglycerides.
  37. What are phospholipids?
    Phospholipids are a phosphate group with one or more long hydrocarbon chains attached. They also usually have one or more polar molecules as well.
  38. What are glycerophospholipids?
    Glycerophospholipids are molecules made from:

    • Glycerol
    • Two fatty acids
    • A phosphate group
    • And one extra polar mollecule

    The polar molecule is usually an amino alcohol with the alcohol group and amine group separated by two carbons.

    Each of the four parts of a glycerophospholipid have alcohol groups. Condensation reactions are necesarry at each point where the different parts bind so that the disconnected OH HO become connected -O-.

    • fatty acid - glycerol - phosphate - polar molecul
    • fatty acid -
  39. What is the lipid bilayer?
    Lipid bilayer is the membrane around a cell made up of glycerolphospholipids with the hydrophilic portions pointed away from each other ( outwardly towards the outside of the cell and inwardly towards the inside of the cell ) and their hydrophobic hydrocarbon portions pointed towards each other.

    The lipid bilayer prevents things getting into or out of the cell which are not inteded to, while still allowing things that are supposed to enter and exit the cell to pass through.
  40. What are transport proteins?
    Transport proteins are proteins that act as a passage through the lipid bilayer, allowing only certain things through based either on its size or shape.
  41. What is passive transport in regards to transport proteins?
    A passageway in a cell membrane that allows solute in or out based on the concentration on either side of the cell wall.
  42. What is active transport in regards to transport proteins?
    Transport proteins that actively expels solute from a lower concentration on one side of a cell membrane to a higher concentration on the other side using energy in the process.
  43. What are steroids?
    A class of lipids made up of 4 linked hydrocarbon rings ( hex-hex-hex-pent ), called the steroid nucleus, plus some other stuff added on. Steroids perform a variety of functions
  44. What are lipoproteins?
    Clusters of choloesterol, triglycerides, other lipids, surrounded by a hydrophilic protein coating.

    LDL is low-density-lipoprotein, it moves choloesterol from the liver to other tissues. But if there is too much of it in the body it just starts dumping cholesterol in arteries. This is how it gets the name "bad cholesterol".

    HDL helps pick up some of this cholesterol and takes it back to the liver, this is how it gets its name "good cholesterol".