biochem carbo

• Carbohydrates


  • Most abundant biomolecule in nature

  
  

  • Have important structural and metabolic roles

  
  

  • They are polyhydroxy aldehydes and ketones or compounds that produce such substances upon hydrolysis
• Photosynthesis


  - 75% of dry plant material is produced by?
• Cellulose


  Carbohydrate component of plant cell walls.
• starch and glycogen


  large storage forms of glucose found in plants and animals.

  
  

  Energy reservoir
• Plant products


  sources of carbohydrates

  
  

  • Average human diet contains 2/3 of carbohydrates
• Carbohydrates oxidation -


  provides energy
• (proteins, lipids, and nucleic acids)


  Carbohydrates supply carbon atoms for the synthesis of other biochemical substances like?
• f DNA and RNA molecules


  Carbohydrates form part of the structural framework of?
• Monosaccharides


  • Sugars that cannot be hydrolyzed into simpler carbohydrates

  
  

  • May be classified depending upon the number of carbon atoms

  
  

  • Depending upon whether they have an aldehyde or ketone group
• Oligosaccharides


  • Contains 2-10 monosaccharide units covalently bonded

  
  

  • Upon hydrolysis, they produce monosaccharides

  
  

  • Associated with structural and regulatory functions in the human body
• Sucrose (AKA table sugar) Lactose (AKA milk sugar)


  • Common disaccharides
• Polysaccharides


  • Contains more than ten monosaccharide units covalently bonded
• paper, cotton, wood


  Example of Cellulose
• bread, pasta, potatoes, rice, corn, beans


  examples of starch
• Superimposable


  = images that coincide at all points when the images are laid up on each other
• Non-superimposable


  on their mirror images: Chiral (handedness)
• D and L Isomerism

  
  

  - orientation of the —H and —OH groups around the carbon atom adjacent to the terminal primary alcohol carbon
• D-sugars


  Most of the monosaccharides occurring in mammals are?
• Right handed


  Almost all monosaccharides are?
• left handed


  Amino acids are almost always?
• glyceraldehyde


  The simplest carbohydrate that contains a chiral carbon is?
• Isomers


  each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties
• Stereoisomers


  each of two or more compounds differing only in the spatial arrangement of their atoms
• Enantiomer


  each of a pair of molecules that are mirror images of each other
• Diastereomers


  Also differ in boiling points and freezing points
• Epimers


  These are diastereomers whose molecules differ only in the configuration at one chiral center
• Tetrahedral Arrangements


  • The four groups attached to the atom at the chiral center assume a tetrahedral geometry and its is governed by the following conventions
• Vertical lines from the chiral center


  represent bonds to groups directed into the printed page
• Horizontal lines


  represent bonds to groups directed out of the printed page
• Pyranose and Furanose Ring Structures


  Sugars that Exhibit Various Forms of Isomerism
• • Cardiac Glycosides


  - Digoxin

  
  

  - Important in medicine because of their action on the heart
• aglycone


  nonsugar molecule attached to the anomeric sugar carbon
• glucoside


  glycoside produced from glucose
• galactoside


  glycoside produced from galactose
• streptomycin


  Aminoglycoside
• alpha and beta isomers


  - isomerism occurs about position 1

  
  

  - the carbonyl or anomeric carbon atom
• beta configuration


  both of these groups point in the same direction
• alpha configuration


  two groups point in opposite directions
• mannose and galactose


  Biologically, the most important epimers of glucose are?
• Glucose


  70-100mg/100mL bld

  
  

  - Fruit juices, cane sugar, beet sugar

  
  

  -main metabolic fuel for tissues

  
  

  -AKA grape sugar (20-30%), BLOOD SUGAR, dextrose