1. Introductory Biochemistry BIOC
Dr Ebtihaj Jambi
Room 2125

2. Books

3. The performance in this course will be evaluated in five areas : home works , lab. Exam and two exams
Home works……………………………………….5%
First exam ………………………………………..15 %
Second exam …………………………………….15 %
Lab. Exam…………………………………….….25%
Final exam ……………………………………….40 %

4. االسياسات الواجب الإلتزام بها: ● تحرم الطالبة من الإختبار النهائي إذا تجاوز غيابها 8 مرات بدون عذر ● على كل طالبة الإلتزام بتأدية الإختبارات بالشعبه الرسميه المسجله بها ● التخلف عن أحد الإختبارات الدورية بعذر طبي و ان يكون التقرير الطبي مصدق من جهة حكومية ● إغلاق الجوال أثناء المحاضرة ● الإلتزام باللبس المحتشم وإلا سوف يحسب غياب للطالبة بدون عذر ● تسليم الواجبات في الموعد المحدد ● عدم لبس العباءة أثناء المحاضرة أو الإختبار ●إحضار قلم رصاص الخاص بالتصحيح الألي HB عند تأدية الإختبارات .

5. The important Dates: Section Sat. Mon. 1- The First Exam ………
The important Dates: Section Sat. Mon. 1- The First Exam ……….22/11/ The Second Exam… / 1 / The home work…

6. What is Biochemistry? Biochemistry = chemistry of life.
Biochemists use physical and chemical principles to explain biology at the molecular level.
Basic principles of biochemistry are common to all living organism

7. How does biochemistry impact you?
Medicine
Agriculture
Industrial applications
Environmental applications

8. Principle Areas of Biochemistry
Structure and function of biological macromolecules
Metabolism – anabolic and catabolic processes.
Molecular Genetics – How life is replicated. Regulation of protein synthesis

9. Organization of Life elements simple organic compounds (monomers)
macromolecules (polymers)
supramolecular structures
organelles
cells
tissues
organisms

10. Range of the sizes of objects studies by Biochemist and Biologist
1 angstrom = 0.1 nm

11. Elements of Life
Most abundant, essential for all organisms: C, N, O, P, S, H
Less abundant, essential for all organisms : Na, Mg, K, Ca, Cl
Trace levels, essential for all organism: Mn, Fe, Co, Cu, Zn
Trace levels, essential for some organisms: V, Cr, Mo, B, Al, Ga, Sn, Si, As, Se, I,

12. Important compounds, functional groups

13. Many Important Biomolecules are Polymers
lipids
proteins
carbo
nucleic acids
monomer
polymer
supramolecular
structure

14. Lipids
monomer
polymer
supramolecular
structure

15. Proteins monomer polymer supramolecular structure amino acid
Enzyme complex
protein subunit
amino acid

16. Carbohydrates
monomer
polymer
supramolecular
structure

17. Nucleic Acids
monomer
polymer
supramolecular
structure

18. Prokaryote Cell

19. Cellular Organization of an E. coli Cell
200 – 300 mg protein / mL cytoplasm

20. Eukaryote Cell

21. Carbohydrate

22. Carbohydrates Most abundant class of biological molecules on Earth
Originally produced through CO2 fixation during photosynthesis
Carbohydrate are aldehyde or ketone compounds with multiple hydroxyl group

23. Function
Function, the primary function of carbohydrates is to provide energy for the body, especially the brain and the nervous system. An enzyme called amylase helps break down carbohydrates into glucose (blood sugar), which is used for energy by the body.

24. Function Energy storage (glycogen,starch)
Structural components (cellulose,chitin)
Cellular recognition
Carbohydrate derivatives include DNA, RNA, co-factors, glycoproteins, glycolipids

25. The word carbohydrate means
"hydrate of carbon" and derives from the formula (CH2O)n
Glucose (blood sugar): C6H12O6 which can be written as C6 (H2O)6 ;
Sucrose (table sugar): C12 H22O11 which can be written as C12 (H2O)11

26. depending on the number of simple sugars they contain.
●The simpler members of the carbohydrate family are often referred to as saccharides.
● Carbohydrates are classified as
Monosaccharides n≥3
Oligosaccharides
Polysaccharides ≥ 20
depending on the number of simple sugars they contain.

29. Mono­saccharides
containing an aldehyde group are classified as
aldoses;
those
containing a ketone group are classified as
ketoses.
●There are only two trioses:
the aldotriose glyceraldehyde
the ketotriose dihydroxyacetone.

32. Monosaccharides Polyhydroxy ketones (ketoses) and aldehydes (aldoses)
Aldoses and ketoses contain aldehyde and ketone functions, respectively
Triose, tetrose, etc. denotes number of carbons

33. Fischer Projection Formulas

35. D- and L-Monosaccharides
The configuration of carbohydrates is commonly designated using the D, L system proposed by Emil Fischer in 1891.
Enantiomer of glyceraldehyde has a specific rotation of °; the other has a specific rotation of -13.5°.
Fischer proposed that these enantiomers be designated D and L, but he had no experimental way to determine which enantiomer has which specific rotation.

37. D-glyceraldehyde and L-glyceraldehyde serve as reference points for the assignment of relatively configurations to all other aldoses.
D- dihydroxyacetone and L- dihydroxyacetone serve as reference points for the assignment of relatively configurations to all other ketoses.
  ●A D-monosaccharide has the same configuration at its penultimate carbon as D-glyceraldehyde
(its -OH group is on the right) in a Fischer projection;
●an L-monosaccharide has the same configuration at its penultimate carbon as L-glyceraldehyde
(its -OH group is on the left).

38. Monosaccharides are chiral
The number of chiral carbons present in a ketose is always one less than the number found in the same length aldose
Number of possible steroisomers = 2n (n = the number of chiral carbons)

39. Stereochemistry Enantiomers = mirror images
Pairs of isomers that have opposite configurations at one or more chiral centers but are NOT mirror images are diastereomers
Epimers = Two sugars that differ in configuration at only one chiral center

40. N-Acetyl-D-glucosamine, (a derivatIve of D-glucosamine),
D. Amino Sugars
N-Acetyl-D-glucosamine,
(a derivatIve of D-glucosamine),
is a component of many polysaccharides, including connective tissue such as cartilage, chitin, the hard, shell-like exoskeleton of lobsters, crabs, shrimp, and other shellfish.
Several other amino sugars are components of naturally occurring antibiotics.

42. E. Physical Properties of Monosaccharides
●Monosaccharides are colorless, crystalline solids.
●all monosaccha­rides are very soluble in water. Because hydrogen bonding is possible between their polar – OH groups and water,
● slightly soluble in ethanol and
● insoluble in nonpolar solvents such as diethyl ether, dichloromethane, and benzene.

43. What Are the Cyclic Structures of Monosaccharides?
we saw that aldehydes and ketones react with alcohols to form hemiacetals.
We also saw that cyclic hemiacetals form very readily when hydroxyl and carbonyl groups are part of the same molecule and that their interaction produces a ring.

45. Monosaccharides have hydroxyl and carbonyl groups in the same molecule
Monosaccharides have hydroxyl and carbonyl groups in the same molecule. As a result, they exist almost exclusively as five- and six-membered cyclic hemiacetals.

47. Cyclization of aldose and ketoses introduces additional chiral center
Aldose sugars (glucose) can cyclize to form a cyclic hemiacetal
Ketose sugars (fructose) can cyclize to form a cyclic hemiketal

48. A. Haworth Projections A common way of representing the
cyclic structure of monosaccharides
is the Haworth projection, named after the English chemist Sir Walter N. Haworth
(Nobel Prize for chemistry, 1937).

49. In a Haworth projection, a five ­or six-membered cyclic hemiacetal is represented as a planar pentagon or hexagon,
six-membered hemiacetal ring is indicated by -pyran-, pyranose
five ­membered hemiacetal ring is indicated by -furan-. furanose
Groups bonded to the carbons of the ring then lie either above or below the plane of the ring.
The new carbon stereocenter created in forming the cyclic structure is called an anomeric carbon.
Stereoisomers that differ in configuration only at the anomeric carbon are called anomers.
The anomeric carbon of an aldose is carbon 1; that of the most common ketoses is carbon 2.

51. Monosaccharides can cyclize to form Pyranose / Furanose forms
b = 36%
a = 21.5%
b = 58.5%
a = 13.5%
b = 6.5%

52. Glucose can exist in both a straight-chain and ring form

53. ●the designation ß means that the -OH on the anomeric carbon of the cyclic hemiacetal lies on the same side of the ring as the terminal –CH2OH.
●the designation α means that the -OH on the anomeric carbon of the cyclic hemiacetal lies on the side of the ring opposite from the terminal-CH2OH.

56. -OH up = beta 6 5 4 1 2 3 Haworth Projections -OH down = alpha
Anomeric carbon
(most oxidized)
For all non-anomeric carbons, -OH groups point down in Haworth projections if pointing right in Fischer projections

57. C. Mutarotation
The change in specific rotation that accompanies the equilibration of α and ß anomers in aqueous solution.
A solution prepared by dissolving crystalline α-D-glucopyranose in water has a specific rotation of
+ 112°, which gradually decreases to an equilibrium value of +52.7° as α-D-glucopyranose reaches equilibrium with ß-D-glucopyranose.

59. + 18.7° to the same equilibrium value of +52.7°.
A solution of ß -n-glucopyranose also undergoes mutarotation, during which the specific rotation changes from
+ 18.7° to the same equilibrium value of +52.7°.
The equilibrium mixture consists of
64% ß-D-glucopyranose and
36% α-D-glucopyranose,
with only a trace (0.003% ) of the open-chain form.

61. What Are the Characteristic Reactions of Monosaccharides?

62. A. Formation of Glycosides (Acetals)
Treatment of an aldehyde or ketone with one molecule of alcohol yields a hemiacetal,
and treatment of the hemiacetal with a molecule of' alcohol yields an acetal.
Treatment of a monosaccharide all forms of which exist almost exclusively as cyclic hemiacetals­ with an alcohol also yields an acetal,

64. Mutarotation is not possible in a glycoside because an acetal-unlike a hemiacetal-is no longer in equilibrium with the open­ chain carbonyl-containing compound.
Glycosides are stable in water and aqueous base; however, they are hydrolyzed in aqueous acid to an alcohol and a monosaccharide.

65. B. Reduction to Alditols
The carbonyl group of a monosaccharide can be reduced to a hydroxyl group by a variety of reducing agents, including hydrogen in the presence of a transition metal catalyst and sodium borohydride. The reduction products are known as alditols.

67. Sorbitol is found in the plant world in many berries and in cherries, plums, pears, apples, seaweed, and algae.
It is about 60% as sweet as sucrose (table sugar) and is used in the manufacture of candies and as a sugar substitute for diabetics. Other alditols commonly found in the biological world include erythritol, n-mannitol, and xylitol.
Xylitol is used as a sweetening agent in "sugarless" gum, candy, and sweet cereals.

69. C. Oxidation to Aldonic Acids (Reducing Sugars)
Aldehydes (RCHO) are oxidized to carboxylic acids (RCOOH) by several agents, including oxygen, O2 .

70. Similarly, the aldehyde group of an aldose can be oxidized, under basic conditions, to a carboxylate group.
The cyclic form of the aldose is in equilibrium with the open-chain form, which is then oxidized by the mild oxidizing agent.
D-Glucose, for example, is oxidized to
D-gluconate (D-gluconic acid).

72. Reducing and Non Reducing Sugar of Carbohydrates
Reducing sugar: In Reducing sugar, the two groups ,aldehyde and ketone do not take part in the formation of glycosidic bond and are present in a free or potentially free state and as such renders them powerful reducing agent.
Reducing sugar include glucose, fructose, lactose which can reduce metal ions like Ca2+ ,Fe3+ ,in an alkaline medium.
Non Reducing sugar: In non reducing sugar ,aldehyde and ketone group are involved in the formation of glycosidic bonds and thus are not free. Sucrose is a non reducing sugar.

73. Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion.
Reduction is the gain of electrons or a decrease in oxidation state by a molecule, atom, or ion.

74. Reducing Sugars
When in the uncyclized form, monosaccharides act as reducing agents.
Free carbonyl group from aldoses or ketoses can reduce Cu2+ and Ag+ ions to insoluble products

75. D. Oxidation to Uronic Acids Enzyme-catalyzed oxidation of the primary alcohol at carbon 6 of a hexose yields a uronic acid. Enzyme- catalyzed oxidation of D-glucose, yields D-glucuronic acids,

77. D-Glucuronic acid is widely distributed in- both the plant and animal worlds.
In humans, it serves as an important component of the
■ acidic poly­saccharides of connective tissues,
■ to detoxify foreign phenols and alcohols.
■ In the liver, these compounds are converted to glycosides of glucuronic acid (glucuronides) and excreted in the urine.
■The intravenous anesthetic propofol, for example, is converted to the following glucuronide and then excreted in urine

79. E. The Formation of Phosphoric Esters
Mono- and diphosphoric esters are important intermediates in the metabolism of monosaccharides.
For example, the first step in glycolysis involves conversion of glucose to glucose 6-phosphate. Note that phosphoric acid is a strong enough acid so that at the pH of cellular and intercellular fluids, both acidic protons of a phosphoric ester are ionized, giving the ester a charge of -2.

81. F- Osazone Formation
The osazone reaction was developed and used by Emil Fischer to identify aldose sugars differing in configuration only at the alpha-carbon. which effects an alpha-carbon oxidation with formation of a bis-phenylhydrazone, known as an osazone

82. The technique was developed by Emil Fischer ,,aGerman chemist.

83. Application of the osazone reaction to D-glucose and D-mannose demonstrates that these compounds differ in configuration only at C-2.

85. Derivatives of Monosaccharides

86. Sugar Phosphates

87. Deoxy Acids

88. Amino Sugars

89. Sugar alcohols

90. What Are Disaccarides and Oligosaccharides?
Disaccharide a carbohydratc containing two monosaccharide units joined by a glycosidic boned
Most carbohydrates in nature contain more than one monosaccharide unit.

91. ●disaccharides : those that contain two units
●trisaccharides: three units
●oligosaccharide: contain from six to ten monosaccharide units.
●polysaccharides: carbohydrates containing larger numbers of monosaccharide units.

92. ◊ In a disaccharide, two monosaccharide units arc joined by a glycosidic bond between the anomeric carbon of one unit and an -OH group of the other unit.
◊ Three important disaccharides are sucrose,lactose, and maltose.

93. Figure 3: Glycosidic Bond Formation
sugar1-OH     +    HO-sugar2    
sugar1-   +   -O-sugar2  +  -OH  +   H-    
sugar1-O-sugar2  +  HOH
Figure 3: Glycosidic Bond Formation

94. A. Sucrose
Sucrose (table sugar) is the most abundant disaccharide in the biological world.
●It is obtained principally from the juice of sugar cane and sugar beets
●carbon 1 of a-D-glucopyranose bonds to carbon 2 of D­fructofuranose by an a-l,2-glycosidic bond.

95. Glucose (left) and Fructose (right)

99. ● non reducing sugar. Because the anomeric carbons of both the glucopyranose and fructofuranose units are involved in formation of the glycosidic bond, neither monosaccharide unit is in equilibrium with its open-chain form.
● Oligosaccharide A carbohydrate containing from six to ten monosacchariede units, sauch joincd to thc next by a glycosidic boned
In the production of sucrose,
sugar cane or sugar beet is boiled with water, and the resulting solution is cooled. Sucrose crystals separate and are collected. Subsequent boiling to concentrate the solution followed by cooling yields a dark, thick syrup known as molasses.

100. B. Lactose ◊ Lactose is the principal suger present in milk.
◊ It accounts for 5 to 8% of human milk and 4 to 6% of cows milk.
◊ Consists of D-galactopyranose bonded by a β-1,4-glycosidic bond to carbo 4 D-glucopyranose.
◊ Lactose is a reducing suger, because the cyclic hemiacetal of the D- glucopyranose unit is in equilibrium with its open- chain form and can be oxidized to a carboxyl group.

101. The Aldohexoses Galactose (left) and Glucose (right)

104. 3. alpha-galactose     + beta-glucose
2. beta-galactose     + beta-glucose
1. alpha-galactose     + alpha-glucose
4. beta-galactose     + alpha-glucose

107. C. Maltose
●Maltose derives its name from its presence in malt, the juice from sprouted barley and other cereal grains.
●It consists of two units of D-glucopyranose joined by glycosidic bond between carbon 1 (the unomeric r:arbon) of one unit and carbon 4 of the other unit.

111. ●Because the oxygen atom on the anomeric carbon of' the first glucopyranose unit is alpha, the bond joining the two units is an α-l,4-glycosidic bond. Following are a Haworth projection and a chair conformation for ß-maltose, so named because the -OH groups on the anomeric carbon of the glucose unit on the right are beta.
●Maltose is a reducing sugar; the hemiacetal group on the right unit of 11­glucopyranose is in equilibrium with the free aldehyde and can be oxidized to a carboxylic acid.

112. D. Relative Sweetness Among the disaccharide sweetening agents,
n-fructose tastes the sweetest even sweeter than sucrose.
The sweet taste of honey is due largely to 11-fructose and D-glucose.
Lactose has almost no sweetness and is sometimes added to foods as a filler.

113. Sweetness
Sugar
173%
fructose
100%
sucrose
74%
glucose
33%
maltose
galactose
16%
Lactose

114. What Are Polysaccharides?
Polysaccharides consist of large numbers of monosaccharide units bonded together by glycosidic bonds. Three important polysaccharides, all made up of glucose units, are starch, glycogen, and cellulose.

116. A. Starch: Amylose and Amylopectin
●Starch is used for energy storage in plants.
●It is found in all plant seeds and tubers and is the form in which glucose is stored for later use.
●Starch can be separated into two principal polysaccharides:
amylose and amylopectin, most starches contain 20 to 25% amylose and 75 to 80% mylopectin.

118. Complete hydrolysis of both amylose and amylopectin yields only D-glucose.
Amylose is composed of continuous, unbranched chains of as many as 4000 n-glucose units joined by α-l,4-g1ycosidic bonds.
Amylopectin contains chains of as many as 10,000 D-glucose units also joined by α-l,4-g1ycosidic bonds. In addition, considerable branching from this linear network occurs. New chains of 24 to 30 units are started at branch points by α-l,6-g1ycosidic bonds.

120. B. Glycogen
Glycogen acts as the energy-reserve carbohydrate for animals.
it is a branched polysaccharide(Like amy­lopectin), containing approximately.lO6 glucose units joined by α-l,4- and α-l,6-glycosidic bonds.
The total amount of glycogen in the body of a well-nourished adult human is about 350 g, divided almost equally between liver and muscle.

121. C. Cellulose
Cellulose, the most widely distributed plant skeletal polysaccharide, con­stitutes almost half of the cell-wall material of wood. Cotton is almost pure cellulose.
Cellulose is a linear polysaccharide of D-glucose units joined by ß-1,4-gly­cosidic bonds.
It has an average molecular weight of 400,000 g/mol, corresponding to approximately 2200 glucose units per molecule.

123. Why cellulose is insoluble in water?
Cellulose molecules act much like stiff rods, a characteristic that enables them to align themselves side by side into well-organized, water-insoluble fibers in which the OH groups form numerous intermolecular hydrogen bonds. This arrangement of parallel chains in bundles gives cellulose fibers their high mechanical strength.

124. When a piece of cellulose-containing material is placed in water, there are not enough -OH groups on the surface of the fiber to pull individual cellulose molecules away from the strongly hydrogen-bonded fiber.

125. Humans and other animals cannot use cellulose as food because our digestive systems do not contain ß-g1ucosidases, enzymes that catalyze the hydrolysis of ß-glucosidic bonds.
Instead, we have only α-glucosidases; hence, we use the polysaccharides starch and glycogen as sources of glucose.
In contrast, many bacteria and microorganisms do contain ß-g1ucosidases and so can digest cellulose. ◊Termites, Ruminants

126. What Are Acidic Polysaccharides?
Acidic polysaccharides are a group of polysaccharides that contain carboxyl groups and/or sulfuric ester groups.
Acidic polysaccharides play important roles in the structure and function of connective tissues.

127. A. Hyaluronic Acid
●is the simplest acidic polysaccharide present in connective tissue.
●It has a molecular weight of between 105 and 107 glmol and contains from 300 to 100,000 repeating units, depending on the organ in which it occurs.
●It is most abundant in embryonic tissues and in specialized connective tissues such as synovial fluid, the lubricant of joints in the body, and the vitreous of the eye, where it provides a clear, elastic gel that holds the retina in its proper position.

129. ●Hyaluronic acid is also a common ingredient in lotions, moisturizers, and cosmetics.
● Hyaluronic acid is composed of n-glucuronic acid joined by a β-1,3-glycosidic bond to N-acetyli-n-glucosamine, which is in turn linked to' n-glucuronic acid by a β -1,4-glycosidic bond.

130. B. Heparin
●Heparin is a heterogeneous mixture of variably sulfonated polysaccharide chains,
●ranging in molecular weight from 6000 to 30,000 g/mol.
● This acidic polysaccharide is synthesized and stored in mast cells of various tissues­ particularly the liver, lungs, and gut.

131. ●Heparin has many biological functions, is anticoagulant
●Heparin has many biological functions, is anticoagulant. It binds strongly to antithrombin III, a plasma protein involved in terminating the clotting process.
●A heparin preparation with good anticoagulant activity contains a minimum of eight repeating units . The larger the molecule, the greater its anticoagulant activity.
●Because of this anticoagulant activity, it is widely used in medicine.