BUILDING BLOCKS OF CELLS Flashcards
WHAT % OF BODY DOES WATER MAKE UP?
60% (2/3 intra, 1/3 extra)
WHAT % OF BODY DO PROTEINS, AMINO ACIDS AND PEPTIDES MAKE UP?
18%
WHAT % OF THE HUMAN BODY DO LIPIDS TAKE UP?
15%
WHAT % OF THE BODY DO SACCHARRIDES TAKE UP?
1%
WHAT % OF THE BODY DO NUCLEIC ACIDS AND NUCLEOTIDES TAKE UP?
1%
WHAT % OF THE BODY DO OTHER MINERALS TAKE UP?
5%
WHAT IS THE CHEMICAL COMPOSITION OF CELLS?
-60% water
-35% organic materials
-5% inorganic materials
HOW MANY CARBONS DO THE SIMPLEST MONOSACCHARIDES HAVE?
-3
EG: GLYCERALDEHYDE
HOW CAN MONOSACCHARIDES BE CLASSIFED?
-via functional groups of aldehydes (glyceraldehyde) and ketones (dihydroxyacetone)
KETOSE = ribulose, fructose (carbonyl at C2) (2 primary alcohols)
ALDOSE = ribose, glucose, mannose (C2 epimer of glucose), galactose (C4 epimer of glucose) (1 primary alcohol) (carbonyl group at beginning an 5 other OH groups) = very reactive with alcohol and amino groups
-via number of carbons (triose C3, tetrose C4, pentose C5, hexose C6, heptose C7)
PENTOSE = ribose, deoxyribose, ribulose
HEXOSE = glucose, fructose, galactose, mannose
PRIMARY ALCOHOL GROUP = terminal alcohol - all the rest are secondary alcohols
HOW DOES THE ORDER OF PRIORITY IN CHIRAL MOLECULES DECREASE?
OH -> CHO -> CH2OH -> H
DO D-ISOMERS OCCUR NATURALLY?
-yes
WHAT IS AN EPIMER?
-isomers that differ by their -OH group orientation around a carbon
EG: - GALACTOSE AND GLUCOSE = isomers which differ by their OH group orientation around the 4th carbon
-mannose is a C2 epimer of glucose
-galactose is a C4 epimer of glucose
GLUCOSE AND MANNOSE = isomers which differ by their OH group orientation around the 2nd carbon
-mannose is a C2 epimer of glucose
ARE THERE MORE NATURAL KETOHEXOSES OR ALDOHEXOES?
1/2 as many natural keto-hexoses than there are aldo-hexoses
WHAT ARE CYLICAL STRUCTURES OF MONOSACCHARIDES?
-hemiacetal bond between the OH (C4 / C5) and carbonyl carbon
-follow Haworth formula
-α (OH group under the plane of circle) a β anomer (D-isomers OH group above the plane)– isomers that differ in the position of hemiacetals
EG: FURANOSE AND PYRANOSE
WHAT DOES GLUCOSE OCCUR AS IN AQUEOUS SOLUTION?
-glucopyranose
- carbon with a double bond binds oxygen from the 5th carbon -> a stable cyclical structure is formed - two different anomers form in different ratios = glucose - α : β = 80 : 20
CYCLIC STURCTURES: ALCOHOLS TO THE RIGHT IN CHAIN POINT DOWN IN CYCLIC AND ALCOHOLS TO THE LEFT POINT POINT UP
WHAT IS A STORAGE POLYSACCHARIDE?
-glycogen
- formed by the connection of α-1,4-glycosidic bond and branched α-1,6- glycosidic bond
-branching allows a faster breakdown of chains
-glucose storage
WHAT MAKES UP STARCH?
-linear amylose and branched amylopectin
GIVE EXAMPLES OF MONOSACCHARIDES
-C3 = glyceraldehyde (aldotriose) and dihydroxyacetone (ketotriose) both important intermediates in human metabolism
-C5 = ribose, 2-deoxyribose (aldopentoses) are components of nucleotides
-C6 = glucose, galactose, mannose (alodhexoses), fructose (ketohexose) are components of oligo and poly saccharides
GIVE EXAMPLES OF DISACCHARIDES
-sucrose (glucose + fructose)
-lactose (galactose + glucose)
-maltose (X2 glucose)
GIVE EXAMPLES OF POLYSACCHARIDES / GLYCANS
-starch (amylose + amylopectin) is a storage polysaccharide of plants (polymer of glucose - glucan)
-glycogen (branched polymer of glucose) is a storage polysaccharide of animal cells
-cellulose (water insoluble polymer of glucose) is a linear and structural polysaccharide of plants
WHAT ARE HETEROGLYCOSIDES?
-complex saccharides
EG: PROTEOGLYCANS, GLYCOPROTEINS, GLYCOLIPIDS
WHAT IS THE STRUCTURE OF MONOSACCHARIDES?
-one aldose or ketose at C2 and 2 or more OH groups
-terminal hydroxy group is a primary alcohol - can be oxidized
-all other hydroxy groups are secondary alcohols
-aldehyde group can be either oxidized or reduced
-ketone group can be reduced
-all carbons of a sugar containing a secondary alcohols are chiral
-ketoses by one C^* less than aldoses
-number of Isomers can be calculated 2^* (n is the number of C)
WHAT IS MUTAROTATION?
-interconversion of the a and B anomeric forms of saccharides
WHAT ARE DERIVATIVES OF SACCHARIDES?
SUGAR ALCOHOLS - formed by reduction of the carbonyl group (glucose = glucitol = sorbitol)
ACIDS = aldaric acids (C1 and C6 oxidized = glucaric), aldonic acids (C1 oxidized = gluconic), alduronic acids (C6 oxidized = glucuronic)
DEOXYSACCHARIDES = reduction of secondary -OH group (2-deoxy-D-ribose)
AMINO SACCHARIDES = contain one amino group instead of -OH group (D-glucose amine) - often acetylated (ORGANIC ESTERIFICATION)
ESTERS = with H3PO4 or H2SO4
GLYCOSIDES = reaction with alcohols or amines - OGLYCOSIDIC - oligo and polysaccharides to proteins N-GLYCOSIDIC - in nucleic acids to proteins (enzymes glycosidases form these bonds)
