ContentsContents

Definition of BiochemistryDefinition of Biochemistry Main Components of living cell Main Components of living cell

and their importanceand their importance Water importance and balanceWater importance and balance Chemistry of carbohydrateChemistry of carbohydrate Blood glucoseBlood glucose Diabetes mellitusDiabetes mellitus

Definition of Definition of biochemistrybiochemistry ChemistryChemistry is the study of the is the study of the

structure and chemical properties of structure and chemical properties of any substance, whileany substance, while

BiochemistryBiochemistry is the science is the science

concerned with the various molecules concerned with the various molecules that occur in living cells and organisms that occur in living cells and organisms and their chemical reactions. and their chemical reactions.

The main components of The main components of living organism areliving organism are

Water.Water. Carbohydrates and their Carbohydrates and their

derivatives.derivatives. Protein and amino acids .Protein and amino acids . Lipids and their derivatives .Lipids and their derivatives . Inorganic constituents. Inorganic constituents.

BiochemicalBiochemical importance of importance of carbohydratescarbohydrates

CarbohydratesCarbohydrates are the first and are the first and most efficient source of energy most efficient source of energy for vital processes.for vital processes. CarbohydrateCarbohydrate foods contain some foods contain some water soluble vitamins and minerals.water soluble vitamins and minerals. Also their content of Also their content of cellulosecellulose is is important in foods to prevent constipation important in foods to prevent constipation because it acts as a roughage i.e. it because it acts as a roughage i.e. it increases the bulk of stool .increases the bulk of stool .

Biochemical importance of Biochemical importance of proteinsproteins

ProteinsProteins are necessary for health , are necessary for health , growth and replacement of tissues growth and replacement of tissues which normally undergo destruction which normally undergo destruction and resynthesis .and resynthesis .

ProteinsProteins provide the body with the provide the body with the essential amino acids that can not be essential amino acids that can not be formed inside the body .formed inside the body .

ProteinsProteins are the major source for are the major source for nitrogen, sulphur and phosphorus for nitrogen, sulphur and phosphorus for the body. the body.

ProteinProtein foods are also rich in some foods are also rich in some members of water soluble vitamins.members of water soluble vitamins.

Biochemical importance of Biochemical importance of fatsfats

FatsFats are the richest source of are the richest source of energy, also they are the most energy, also they are the most rich energy stores.rich energy stores.

FatsFats provide the body with the provide the body with the essential fatty acidsessential fatty acids

FatsFats provide the body with a provide the body with a group of vitamins called “The group of vitamins called “The fat soluble vitamins”.fat soluble vitamins”.

Biochemical importance of Biochemical importance of inorganic constituentsinorganic constituents

The human body requires about The human body requires about eight eight principal mineral elementsprincipal mineral elements which which include: include: calcium,calcium, phosphorusphosphorus, , magnesiummagnesium, , sodiumsodium, , potassiumpotassium, , sulphursulphur, , ironiron and and chlorinechlorine. These are called . These are called bulkbulk or main or main elementselements. Certain other elements . Certain other elements including: including: coppercopper, , zinczinc, , cobaltcobalt, , seleniumselenium, , manganesemanganese and and iodineiodine are needed in micro are needed in micro amounts and are called “amounts and are called “trace elementstrace elements”. ”.

The importance of the The importance of the inorganic constituents areinorganic constituents are

Formation of certain tissues for Formation of certain tissues for example example calcium calcium and and phosphorousphosphorous for for formation bones.formation bones.

clottingclotting of blood needs of blood needs calciumcalcium ions. ions. Formation of hydrochloric acid (Formation of hydrochloric acid (HClHCl) in ) in

the stomach , through a process needs the stomach , through a process needs sodium chloride (sodium chloride (NaClNaCl).).

Biosynthesis of some Biosynthesis of some hormoneshormones needs needs some trace elements , for example some trace elements , for example iodineiodine for thyroxin and zinc for insulin . for thyroxin and zinc for insulin .

Biosynthesis of Biosynthesis of hemoglobinhemoglobin and and myoglobin needs myoglobin needs ironiron..

Water Importance Water Importance total body water is about total body water is about 45 liters liters

It acts as an excellent It acts as an excellent solventsolvent inside the body. inside the body. It is very important for regulation of body It is very important for regulation of body

temperaturetemperature. . It is suitable medium for the different It is suitable medium for the different

metabolicmetabolic pathways. pathways. Many Many wastewaste products are excreted as soluble products are excreted as soluble

form in water .form in water . It enters in the processes of It enters in the processes of digestiondigestion It is comparatively more essential to It is comparatively more essential to lifelife than than

foods.foods. Severe Severe dehydrationdehydration is dangerous hence , is dangerous hence ,

death happens if about death happens if about 2020 % of the body water % of the body water is lost.is lost.

Total body water is

About 45 liters

Extracellular fluid

( outside cells, 15 liters) Intracellular fluid

(inside the cell 30 liters )

tissue fluid (12 liters) Plasma (3 liters)

Maintenance of water balanceMaintenance of water balance

For the body to remain in water For the body to remain in water balance: balance: water gainwater gain should be should be

equal to equal to water loss.water loss.Water gainWater gain Water lossWater loss WaterWater and other and other

fluids taken as such fluids taken as such (about (about 12001200 ml/day) ml/day)

Water of Water of foodsfoods (about (about 100100 ml/day). ml/day).

MetabolicMetabolic water water (about (about 500500 ml/day), ml/day), produced from produced from metabolic processes.metabolic processes.

Urine: about Urine: about 11 liter/day.liter/day.

Faeces (stool), Faeces (stool), about about 100100 ml/day.ml/day.

Sweat and Sweat and expired air: expired air: 600-600-1000 1000 ml/day.ml/day.

Definition of carbohydrateDefinition of carbohydrate

CarbohydratesCarbohydrates are organic compounds are organic compounds which contain carbon, hydrogen and oxygenwhich contain carbon, hydrogen and oxygen

CarbohydratesCarbohydrates are widely distributed in are widely distributed in

living tissue, form an important source of living tissue, form an important source of energy.energy.

They are stored as reserve food in the form They are stored as reserve food in the form

of of glycogenglycogen in animals and in animals and starchstarch in plants. in plants.

Classification of Classification of CarbohydratesCarbohydrates

They are classified according to the They are classified according to the number of sugar units into 3 number of sugar units into 3 groups:groups:

MonosaccharidesMonosaccharides (1 sugar unit) (1 sugar unit) OligosaccharidesOligosaccharides (2 - 10 sugar (2 - 10 sugar

unit) unit) PolysaccharidesPolysaccharides (more than 10 (more than 10

sugar units)sugar units)

11--MonosaccharidesMonosaccharides

This group include sugars of one This group include sugars of one unit , and all members cannot be unit , and all members cannot be hydrolysed to simpler form.hydrolysed to simpler form.

Monosaccharides are classified Monosaccharides are classified according to according to

a-the type of the functional groupa-the type of the functional group

b-the number of carbon atomsb-the number of carbon atoms

a-the type of the functional a-the type of the functional groupgroup

1) 1) AldosugarAldosugar Contain aldehyde Contain aldehyde group group

2) 2) KetosugarKetosugar Contain ketonic group Contain ketonic group

b-the number of carbon b-the number of carbon atoms in toatoms in to

1) 1) TriosesTrioses (Tri means 3) Contain (Tri means 3) Contain three carbon atoms . There are three carbon atoms . There are two types of trioses:two types of trioses:

AldotrioseAldotriose e.g. glycerose e.g. glycerose “Glyceraldehyde “.“Glyceraldehyde “.

KetotrioseKetotriose e.g. dihydroxy acetone. e.g. dihydroxy acetone.

CHO

C OHH

CH2OH

CH2OH

C O

CH2OH

GlyceraldehydGlyceraldehydee

Dihydroxy Dihydroxy acetoneacetone

2) Tetroses2) Tetroses which contain four which contain four carbon atoms (Tetra means carbon atoms (Tetra means 44))

3)3) PentosesPentoses which contain five which contain five carbon atoms (Penta means carbon atoms (Penta means 55))

4)4) HexosesHexoses which contain six which contain six carbon atoms (Hexa means carbon atoms (Hexa means 66))

HexosesHexoses

D- glucoseD- glucose D-galactoseD-galactose D- mannoseD- mannose D-fructoseD-fructose

CHO

C

C

C

OH H

H OH

C

CH2OH

OHH

H OH

CHO

C

C

C

OH H

OH H

C

CH2OH

OHH

H OH

CHO

C

C

C

OH H

H OH

C

CH2OH

HOH

H OH

CH2OH

C

C

C

OH H

H OH

C

CH2OH

O

H OH

DDLD DLLD DDLL DDL

Biochemical and biological Biochemical and biological importance of hexosesimportance of hexoses

1-Glucose (Dextrose )1-Glucose (Dextrose ) : : is the sugar of is the sugar of blood. It is the principle sugar that is blood. It is the principle sugar that is utilized by the tissues giving CO2 , H2O utilized by the tissues giving CO2 , H2O and energy. Glucose is the sugar of grape. and energy. Glucose is the sugar of grape.

2-Fructose (Levulose)2-Fructose (Levulose) : : is present in is present in fruits, honey . Fructose is the sugar of fetal fruits, honey . Fructose is the sugar of fetal blood. Also it is the principle sugar of blood. Also it is the principle sugar of semen.semen.

3-Galactose :3-Galactose : is present in combination is present in combination with glucose in milk sugar (Lactose). with glucose in milk sugar (Lactose).

4-Mannose :4-Mannose : enters in the composition of enters in the composition of mucopolysaccharidesmucopolysaccharides

22--OligosaccharidesOligosaccharides

These sugars are formed by These sugars are formed by condensation of two to ten molecules condensation of two to ten molecules of monosaccharides producing di , tri , of monosaccharides producing di , tri , tetra ……..saccharides .tetra ……..saccharides .

Disaccharides are the most important Disaccharides are the most important group.group.

DisaccharidesDisaccharides

Are formed by condensation of 2 Are formed by condensation of 2 simple sugars (i.e. 2 simple sugars (i.e. 2 monosaccharides). Important monosaccharides). Important examples areexamples are

1) Sucrose1) Sucrose Cane sugar, beet sugar or table sugar.Cane sugar, beet sugar or table sugar. sucrose consists of one molecule of sucrose consists of one molecule of

glucoseglucose and one molecule of and one molecule of fructosefructose

22)) LactoseLactose

Lactose is the Lactose is the milk sugarmilk sugar human milk has human milk has a concentration of a concentration of 7g %7g % lactose, also it is lactose, also it is the milk sugar of all mammals .the milk sugar of all mammals .

It is formed by condensation of one It is formed by condensation of one molecule of molecule of galactosegalactose with a molecule of with a molecule of glucoseglucose

It considered a perfect sugar for It considered a perfect sugar for babiesbabies because of It is because of It is not fermentednot fermented, so do not , so do not produce produce gasesgases, not so , not so sweatysweaty, mild , mild laxativelaxative effects and the only natural effects and the only natural source of source of galactosegalactose

33--MaltoseMaltose

MaltoseMaltose is formed by is formed by condensation of two molecule condensation of two molecule of of glucoseglucose

MaltoseMaltose is produced during is produced during digestion of cooked digestion of cooked starchstarch by by salivary amylase salivary amylase

33--PolysaccharidesPolysaccharides

1-They are composed of a great number of 1-They are composed of a great number of

monosaccharide units monosaccharide units

2-They are economically important beside 2-They are economically important beside

their great importance in nutrition. Some their great importance in nutrition. Some

important industries are dependent on important industries are dependent on

polysaccharides, e.g.:polysaccharides, e.g.:

Manufacture of textiles.Manufacture of textiles. Manufacture of artificial silk.Manufacture of artificial silk.

Manufacture of paper.Manufacture of paper.

Classification of Classification of polysaccharidespolysaccharides

A-A-HomopolysacchariHomopolysacchari

des des

B-B-HeteropolysacchariHeteropolysacchari

des des

Formed of only one Formed of only one type of sugar type of sugar

Contain different Contain different SugarSugar

Examples: starch, Examples: starch, dexterines, dextrans, dexterines, dextrans, glycogen and glycogen and cellulosecellulose

Examples: gums, Examples: gums, pectin and pectin and mucopolysaccharidesmucopolysaccharides

A- HomopolysaccharidesA- Homopolysaccharides

1-Starch 1-Starch : : Starch is the main carbohydrate of Starch is the main carbohydrate of

food it is the main storage from of food it is the main storage from of

carbohydrates in plantscarbohydrates in plants ..

It exists in cereals (e.g. rice ,barley , It exists in cereals (e.g. rice ,barley ,

maize and wheat ) and in roots and maize and wheat ) and in roots and

tubers like potatoes and sweat tubers like potatoes and sweat

potatoes.potatoes.

Starch never present in animals. Starch never present in animals.

2-Dextrins:2-Dextrins: They are produced during enzymatic They are produced during enzymatic hydrolysis of starch by salivary hydrolysis of starch by salivary amylase or pancreatic amylase amylase or pancreatic amylase enzymes.enzymes.

3-Dextrans:3-Dextrans: These are polysaccharides produced by These are polysaccharides produced by the actions of certain bacteria when the actions of certain bacteria when allowed to grow on sucrose media . It allowed to grow on sucrose media . It is used as plasma substitute to is used as plasma substitute to increase blood volume after severe increase blood volume after severe haemorrhage haemorrhage

44--GlycogenGlycogen Glycogen is the main storage from Glycogen is the main storage from

of carbohydrates in of carbohydrates in animalsanimals ((Sometimes called animal starch ).Sometimes called animal starch ).

It is stored in It is stored in liver and musclesliver and muscles..

Glycogen granules in a hepatocyte. These granules form in the cytosol, and are much smaller than starch granules in plants.

Glycogen granules

5-Ag5-Agar-agarar-agar::

Agar agar is a polysaccharides Agar agar is a polysaccharides

formed of galactose.formed of galactose.

It is prepared from sea weeds.It is prepared from sea weeds.

The importance of agar agar is due The importance of agar agar is due

to its use as a culture medium for to its use as a culture medium for

growing of bacteria in growing of bacteria in

bacteriological studies.bacteriological studies.

6-Cellulose6-Cellulose:: Constitutes the Constitutes the walls walls of plant cells.of plant cells.

It is formed from It is formed from glucose glucose units joined units joined together together

It is It is insolubleinsoluble in water therefore its in water therefore its fibers are used in manufacturing of fibers are used in manufacturing of

textiles.textiles. Cellulose is Cellulose is not digestednot digested by digestive by digestive juices, however ,cellulose is important juices, however ,cellulose is important in our in our diet diet for preventing for preventing constipationconstipation

B- B- HeteropolysaccharidesHeteropolysaccharides

1-Gums1-Gums::Gums are derived from plants, they Gums are derived from plants, they

consist of a mixture of hexoses, consist of a mixture of hexoses, pentoses and sugar acids pentoses and sugar acids

2-Pectins2-Pectins::Pectins are present in fruits , they Pectins are present in fruits , they

are responsible for the gelling are responsible for the gelling properties of jams. They are used in properties of jams. They are used in the treatment of infantile diarrhea.the treatment of infantile diarrhea.

3-Mucopolysaccharides:3-Mucopolysaccharides: They are distributed in animal tissues They are distributed in animal tissues

either combined with proteins in either combined with proteins in the form of mucoproteins or in free the form of mucoproteins or in free form. form.

They enter in the structure of most They enter in the structure of most tissues and are not oxidized to give tissues and are not oxidized to give energy. They give more than one energy. They give more than one kind of sugar on hydrolysis . kind of sugar on hydrolysis .

DIGESTION OF CARBOHYDRATESDIGESTION OF CARBOHYDRATES

Blood glucose levelBlood glucose level

Normal blood glucose level:Normal blood glucose level:

Fasting blood level Range from 60-110 mg\dl

Direct after meal Range from 80-140 mg\dl

Two hours after meal Range from 70-140 mg\dl

Factors affecting blood Factors affecting blood glucose levelglucose level::

1.1. liverliver : :NUTRIENT DISTRIBUTION NUTRIENT DISTRIBUTION CENTERCENTER

2.2. RenalRenal regulation regulation

3.3. HormonalHormonal regulation regulation

11--Liver: Liver: NUTRIENT DISTRIBUTION NUTRIENT DISTRIBUTION CENTERCENTER

After a mealAfter a meal containing carbohydrate, containing carbohydrate, the liver becomes a net consumer of the liver becomes a net consumer of glucose, hepatic metabolism of glucose is glucose, hepatic metabolism of glucose is increased by:increased by:

increased phosphorylation of glucose andincreased phosphorylation of glucose and Increased glycogen synthesisIncreased glycogen synthesis

due to increase in the secretion of due to increase in the secretion of insulininsulin which is a glucose lowering hormone which is a glucose lowering hormone

During fastingDuring fasting the liver first the liver first uses glycogen degradation, uses glycogen degradation, then gluconeogenesis (glucose then gluconeogenesis (glucose synthesis) synthesis) due to increase in the due to increase in the secretion of secretion of glucagon and stress glucagon and stress hormoneshormones which are glucose which are glucose increasingincreasing hormones to maintain hormones to maintain blood glucose levels to sustain blood glucose levels to sustain energy metabolism of energy metabolism of brainbrain and and other glucose-requiring tissues.other glucose-requiring tissues...

22--Renal regulationRenal regulation

GlucoseGlucose is continuously filtered by is continuously filtered by renal system, under normal conditions renal system, under normal conditions glucose glucose completely return to completely return to circulationcirculation by reabsorptive renal by reabsorptive renal system, when blood glucose level system, when blood glucose level abnormally abnormally elevatedelevated and exceed the and exceed the capacity of the reabsorptive renal capacity of the reabsorptive renal system (system (renal threshold isrenal threshold is 180 mg\180 mg\dldl) glucose appear in urine ) glucose appear in urine ((glucosuriaglucosuria).).

33--Hormonal regulationHormonal regulation InsulinInsulin is a key regulatory enzyme of blood is a key regulatory enzyme of blood

glucose level, it is a polypeptide hormone glucose level, it is a polypeptide hormone produced by the beta cells of the produced by the beta cells of the islets of islets of langerhanslangerhans of the of the pancreaspancreas. Insulin . Insulin decreases the production of glucose by decreases the production of glucose by inhibiting inhibiting gluconeogenesisgluconeogenesis and the and the breakdown of glycogen.breakdown of glycogen.

It increases It increases glucose uptakeglucose uptake by increasing by increasing the number of glucose transporters in the the number of glucose transporters in the cell membrane. cell membrane.

The The intravenous administrationintravenous administration of insulin of insulin thus causes an immediate decrease in the thus causes an immediate decrease in the concentration of blood glucose. concentration of blood glucose.

Metabolic abnormalities of Metabolic abnormalities of glucose levelglucose level::

Hypoglycemia Hypoglycemia Blood glucose level Blood glucose level equal to or less than 40 mg\dl equal to or less than 40 mg\dl

HyperglycemiaHyperglycemia It is the rise of It is the rise of blood glucose level above normal blood glucose level above normal average levelaverage level

Blood glucose level equal to or less than Blood glucose level equal to or less than 40 40 mg\dl and mg\dl and symptomssymptoms being resolved being resolved within minutes following the within minutes following the administration of glucose.administration of glucose.

HypoglycemiaHypoglycemia is a medical emergency is a medical emergency because the central nervous system (because the central nervous system (CNSCNS) ) has an absolute requirement for a has an absolute requirement for a continuous supply of blood-borne glucose continuous supply of blood-borne glucose to serve as fuel for energy metabolism.to serve as fuel for energy metabolism.

HypoglycemiaHypoglycemia is characterized by: 1) is characterized by: 1) central central nervousnervous system symptoms, system symptoms, including confusion, aberrant behavior, or including confusion, aberrant behavior, or comacoma

11 - -HypoglycemiaHypoglycemia::

Causes of hypoglycemiaCauses of hypoglycemia:: 1- Insulin-induced hypoglycemia:1- Insulin-induced hypoglycemia:

Hypoglycemia occurs frequently in patients with Hypoglycemia occurs frequently in patients with diabetes receiving insulin treatment without diabetes receiving insulin treatment without eating.eating.

2- Postprandial hypoglycemia:2- Postprandial hypoglycemia: This is the This is the second most common form of hypoglycemia is second most common form of hypoglycemia is caused by an exaggerated insulin release caused by an exaggerated insulin release following a meal, prompting transient following a meal, prompting transient hypoglycemia. hypoglycemia.

3- Fasting hypoglycemia:3- Fasting hypoglycemia: Low blood glucose Low blood glucose occurring during fasting is rare, but is more occurring during fasting is rare, but is more likely to present as a serious medical problem. likely to present as a serious medical problem. Often seen in patients with liver damage.Often seen in patients with liver damage.

4- Hypoglycemia4- Hypoglycemia due to alcohol intoxication. due to alcohol intoxication.

Causes of hyperglycemiaCauses of hyperglycemia::

Diabetes mellitusDiabetes mellitus Sever stressSever stress Patient receiving IVF containing Patient receiving IVF containing

glucoseglucose

Diabetes MellitusDiabetes Mellitus::

DiabetesDiabetes is not one disease, but is not one disease, but rather is a heterogeneous group of rather is a heterogeneous group of

syndromessyndromes characterized by an characterized by an elevation of fasting blood glucoseelevation of fasting blood glucose

caused by a relative or absolute caused by a relative or absolute deficiency in deficiency in insulininsulin. .

Diabetes mellitus is the leading Diabetes mellitus is the leading cause of adult cause of adult blindnessblindness and and

aamputationmputation, and a major cause of , and a major cause of renal frenal failureailure, , heart attacksheart attacks, and , and

strokesstrokes. .

Types of Types of diabetes mellitusdiabetes mellitus

Type 1 diabetiesType 1 diabeties The disease is characterizec by an The disease is characterizec by an absolute absolute

deficiency of insulindeficiency of insulin caused by an caused by an autoimmune attack on the cells of the autoimmune attack on the cells of the pancreas. This destruction requires a stimulus pancreas. This destruction requires a stimulus from the environment (such as a from the environment (such as a viralviral infection) and a infection) and a geneticgenetic predisposition. predisposition.

The The metabolic abnormalitiesmetabolic abnormalities of type 1 of type 1 diabetes mellitus include diabetes mellitus include hyperglycemiahyperglycemia, , ketoacidosisketoacidosis , and , and hypertriglyceridemiahypertriglyceridemia. . They result from a deficiency of They result from a deficiency of insulininsulin. Type . Type 1 diabetics must intake 1 diabetics must intake exogenousexogenous insulininsulin injected subcutaneously to control injected subcutaneously to control hyperglycemiahyperglycemia

Type 2 diabetiesType 2 diabeties It has a strong genetic component.

Results from a combination of insulin resistance and dysfunctional cells.

Insulin resistance is the decreased ability of target tissues, such as liver, adipose tissue and muscle, to respond properly to normal circulating concentrations of insulin. Obesity is the most common cause of insulin resistance.

The metabolic alterations observed in type 2 diabetes are milder than those described for the insulin-dependent form of the disease.

Available treatments for diabetes moderate the hyperglycemia, but fail to completely normalize metabolism.

The long-standing elevation blood glucose causes the chronic complications in the form of atherosclerosis, retinopathy, nephropathy, and neuropathy.

Biochemical distrurbance in Biochemical distrurbance in diabetes mellitusdiabetes mellitus::

decrease intracellular glucose a sensation of hunger pain lead to polyphagia (escessive eating)

increase blood glucose cause increase in blood osmolarity thirst sensation (poydepsia)

glucosuria: appear of glucose in urine increase breakdown of tissue proteins

cause muscle wasting decrease antibody formation causing

repeated infection loss of weight poor wound healing hyperlipidemia give atherosclerosis

change in glucose blood level in change in glucose blood level in diabetes mellitus:diabetes mellitus:

NormalNormal Impaired Impaired glucose glucose

utilizatioutilizationn

DiabeticDiabetic

Fasting Fasting blood blood

glucoseglucose

Range Range from from

110-120 110-120 mg\dlmg\dl

Range Range from from

110-120 110-120 mg\dlmg\dl

>>126126 mg\mg\dldl

Two Two hours hours

postprandpostprandialial

Range Range from from

70-140 70-140 mg\dlmg\dl

Range Range from from

140-200 140-200 mg\dlmg\dl

>>200200 mg\mg\dldl

The The EndEnd