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)
WHAT ARE THE HOMOPOLYSACCHARIDES?
-branched starch and glycogen
-unbranched cellulose and inuline
WHAT ARE THE HETEROPOLYSACCHARIDES?
-branched glycoproteins
-unbranched proteoglycans
WHAT MAKES AN AMINOSUGAR / URONIC ACID ?
-proteoglycans + core protein + glycosaminoglycans (GAG)
WHAT IS A NUCLEOTIDE?
-ester of phosphoric acid and a nucleoside
(phosphate + sugar + purine / pyrimidine base)
WHAT IS A NUCLEOSIDE?
-N-containing base + monosaccharide
(purine / pyrimidine base + sugar)
WHAT ARE PURINES?
-pyrimidine + imidazol ring
-contain adenine, guanine, hypoxanhine, xanthine
WHAT ARE PYRIMIDINES?
-pyrimidine ring
-cytosine, uracil, thymine
WHAT ARE NUCLEOTIDE BASES?
-aromatic heterocycles
WHAT DO RIBONUCLEOTIDES CONTAIN?
-N-glycosidic bond, ester bond, anyhydride bond
-formed by reduction of NADPH
WHAT ARE THE PROPERTIES OF NUCLEOTIDES?
-strong absorption of Uv radiation (260nm)
-mainly -nucleosidedi and triphosphates
-purines less stable under acidic conditions
-polar terminal phosphate groups
-ribonucleotides concentration of a sum of them is constant but their ratio changes
-deoxyribonucleotides concentration depends on cell cycle
WHAT ARE RACEMASES?
-enzymes which are able to interconvert between D and L isomers
ARE SACCHARIDES WATER SOLUBLE?
-yes low molecular saccharides are water soluble and sweet tasting
HOW MANY UNITS DO OLIGOSACCHARIDES CONTAIN?
-2 to 10 units
WHAT IS 2^n?
n = number of carbons
formula gives the number of isomers
ARE LIPIDS WATER SOLUBLE?
no lipids are not water soluble
WHAT ARE LIPIDS SYNTHESIZED FROM IN THE BODY?
acetyl-co enzyme A
WHAT BONDS TO LIPIDS FORM?
hydrolysable lipids have an ester or glycosidic bond
WHAT DO LIPIDS CONSIST OF?
fatty acids and alcohol
WHAT ARE HYDROLYZABLE LIPIDS?
simple fats, solids, liquids, waxes and compound phospholipids, lipoproteins and glycolipids
WHAT LIPIDS ARE NON-HYDROLYZABLE?
-alcohols (long chain alkanols, sterols, steroids)
-acids (fatty acids, eicosanoids)
-hydrocarbons (long chains, carotenoids)
WHAT ARE SATURATED FATTY ACIDS?
-palmitic and stearic fatty acid
WHAT ARE UNSATURATED FATTY ACIDS?
-double bonds in cis configuration; oleic acid
WHAT ARE POLYUNSATURATED FATTY ACIDS?
-have more than one double bond; linoleic acid, linolenic acid, arachidonic acid
WHAT IS TRIACYLGLYCEROL / TAG?
-3 fatty acids with ester bonds and glycerol
-hydrolysable
-hydrophobic
-stored in cells as lipid droplets
-function as a source of carbons, energy and heat
WHAT ARE PHOSPHOLIPIDS?
-2 fatty acid tail and a polar phosphate head connected to each other by glycerol
-more polar than glycerol due to phosphate group consisting of 4 oxygen bonds
WHAT CAN FATTY ACIDS FORM ESTERS WITH?
-cholesterol
IS DIHYDROXYACETONE CONSIDERED TO BE A SACCHARIDE?
-yes but it has no chiral carbon and does not occur naturally in nature
HOW MANY CARBOXYLIC ACID GROUPS DO FATTY ACUDS HAVE?
-only 1
WHAT ARE 4 EXAMPLES OF ALCHOLS IN LIPIDS?
1: cholesterol
2: glycerol
3: inositol
4: sfingosin
NAME THESE FATTY ACIDS ACCORDING TO THEIR NUMBER OF CARBONS.
C12 = lauric
C14 = myristic
C16 = palmitic
C18 = stearic
C18:1;9 = oleic
C18:2;9,12 = linoleic (ESSENTIAL)
C18:3;9,12,15 = linolenic (ESSENTIAL)
C20 = arachidic
C20:4;5,8,11,14 = arachidonic (ESSENTIAL)
WHAT IS THE BASIC SKELETON OF STEROIDS FORMED BY?
-tetracyclic hydrocarbon - STERANE
WHAT ARE THE FUNCTIONS OF CHOLESTEROL?
-precursor for all steroids and bile acids
-part of biological membrane
WHAT IS TRYPTOPHAN A DERIVATIVE OF?
-indole
IN WHAT DIRECTION DOES CHAIN SYNTHESIS OF NUCELOTIDES OCCUR?
-synthesis of new chain always occurs in the
5‘ -> 3‘ direction (attaching at 3)
(phosphate - OH direction)
WHAT IS AN ANOMER?
Anomers are cyclic monosaccharides or glycosides that are epimers, differing from each other in the configuration of C-1 if they are aldoses or in the configuration at C-2 if they are ketoses
STRUCTURES OF D-GLUCOSE AND D-FRUCTOSE
STRUCTURES OF GLUCOSE
STRUCTURES OF THE ANOMERS OF GLUCOSE
STRUCTURES OF GLUCOSE IN AQUEOUS SOLUTIONS
STRUCTURES OF THE EPIMERS OF GLUCOSE
STRUCTURES OF IMPORTANT KETOSE MONOSACCHARIDES
STRUCTURES OF IMPORTANT ALDOSE MONOSACCHARIDES
STRUCTURE OF ATP
