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1. MONOSACCHARIDES Aldehydes (Aldoses) Ketones (Ketoses). 2. Both have a carbonyl group. Glyceraldehyde. C 3 H 6 O 3. Center of asymmetry is Carbon 2. D-Glyceraldehyde. L-Glyceraldehyde. Non-identical mirror images [Enantiomers].
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MONOSACCHARIDES Aldehydes (Aldoses) Ketones (Ketoses) 2 Both have a carbonyl group Glyceraldehyde C3H6O3 Center of asymmetry is Carbon 2 D-Glyceraldehyde L-Glyceraldehyde Non-identical mirror images [Enantiomers] Orientation of -OH on next to last carbon indicates D or L
D + L FORMS OF GLUCOSE C6H12O6 3 carbons D-Glucose L-Glucose Stereoisomers-Enantiomers Non identical mirror images Note: orientation of -OH on next to last carbon indicates D or L
STEREOISOMERS 4 Same chemical composition Same functional groups Have different configurations A. ENANTIOMERS Non-identical mirror images e.g. D-Glyceraldehyde L-Glyceraldehyde D - DEXTROROTATORY (rotates polarized light to right) L - LEVOROTATORY (rotates polarized light to left)
B. DIASTEREOISOMERS All configurational isomers which are not enantiomers EPIMERS- One kind of diastereoisomer Same chemical composition Same functional groups Contain two or more asymmetric C Groups on only one asymmetric carbon are arranged differently in space e.g. -D-Glucose e.g. -D-Glucose -D-Galactose-D-Glucose Epimers exist only in compounds with more than 1 asymmetric carbon. 5
EPIMERS Have two or more asymmetric carbons Differ in orientation around only 1 asymmetric carbon 6 carbons C6H12O6 D-Glucose D-Galactose Asymmetric carbons No. 2, 3, 4, 5 Asymmetric carbons with different orientation of groups No. 4 Both compounds are D isomers [-OH on carbon No. 5 is on right]
6 GLUCOSE STRUCTURE Aldehyde + Alcohol Hemiacetal Aldehyde (carbon 1) + Hemiacetal Alcohol (carbon 5) green = hemiacetal b : OH on carbon 1 points up a : OH on carbon 1 points down a-D-Glucose b-D-Glucose
8 RING STRUCTURES - Glucose and Galactose D-Glucose D-Galactose b-D-Glucose b-D-Galactose Difference: orientation of H and OH on carbon 4
9 Low molecular weight precursors of macromolecules Monosaccharides Pentose - five carbon sugar b-D-Ribose b-D-Glucose
Peptidoglycan precursors 10 N-Acetyl glucoseamine N-Acetyl muramic acid
FATTY ACIDS 11 Palmitic acid Oleic acid NEUTRAL LIPIDS + Fatty acids Ester Glycerol + HOH
12 GLYCEROL PHOSPHATE
PHOSPHOLIPIDS Fatty acids plus glycerol Phosphate Phospholipid 13 Neutral region Hydrophobic Electrically charged polar - Hydrophilic
14 AMINO ACIDS - 20 in proteins Glycine Tryptophan + H2O Dipeptide
15 L-Alanine D-Alanine AMINO ACIDS - ENANTIOMERS Non identical mirror images L-Alanine D-Alanine
16 L-Alanine D-Alanine
MONONUCLEOTIDES new linkages 17 A. Glycosidic bonds 1. N-Glycosidic sugar carbon 1-linked to nitrogen ex. Ribose linked to nucleic acid base in mononucleotides 2. O-Glycosidic sugar carbon 1-linked to oxygen ex. Linkage between sugars in polysaccharides GLYCOSIDES
B. Anhydrides- product of condensation of two molecules of acid 18 Acetic acid Acetic anhydride ANHYDRIDE high energy ~ breaking anhydride releases lots of energy
PURINES 19 Adenine Guanine
PYRIMIDINES 20 Cytosine Thymine Uracil
UTP Uridine triphosphate 21 Anhydride bonds Ester [phosphoester] N-Glycosidic bond Pentose Ribose Nucleic acid base Uracil Tri-phosphate
22 WHAT? STRUCTURES OF & FUNCTIONAL GROUPS ON: MONOSACCHARIDES FATTY ACIDS & GLYCEROL PHOSPHATE AMINO ACIDS MONONUCLEOTIDES–PURINES/PYRIMIDINES STEREOISOMERS ENANTIMERS – d AND l AMINO ACIDS DIASTERIOISOMERS – d GLUCOSE, d GALACTOSE WHY: LOW MOLECULAR WEIGHT COMPOUNDS WHICH HAVE DIFFERENT SHAPES AND FUNCTIONAL GROUPS ARE USED TO SYNTHESIZE THE MACROMOLECULES WHICH MAKE UP CELLS. THE PROPERTIES AND FUNCTIONS OF THE MACROMOLECULES ARE DETERMINED BY THE PROPERTIES OF THEIR PRECURSORS. E.G., YOU CANNOT IMAGINE HOW A PROTEIN DOES ITS THING (OFTEN CATALYSIS) UNLESS YOU KNOW AMINO ACIDS. DIFFERENT MEMBERS OF STERIOISOMER PAIRS HAVE DIFFERENT FUNCTIONS (IN BACTERIA) AND BOTH MEMBERS ARE REQUIRED FOR LIFE