Prof.Dr.Nadeem Mohammed Taher

Collage of Nursing

Biochemistry:-this term was introduced by Carl Neuberg

In 1903 (chemical language of life basic to understanding

Biological &medical sciences

Q-Is it essential for the Nurse to study biochemistry?

1- To understanding the basic function of human body

2- To give information regarding the function of the cell

3- To know how the food is digested, absorbed and used

for body building

4- To understand how the body gets energy for day to day

5- To understand the interrelation between various

metabolic processes in the body

Chapter :1

carbohydrates

Carbohydrate include a large group of compounds commonly

known as starches or sugars which are widely distributed in

plants and animals

Plants animals

-------- -----------

Glucose(dextrose) glucose(blood sugar)

Fructose(levelose) glycogen(liver & muscle)

Sucrose(sugar cane) lactose(sugar milk)

Maltose galactose(glycolipids)

starch

Carbohydrate define as polyhydroxy aldehydes or polyhydroxy

ketones or substances that Yild such compounds on hydrolysis

H CH2OH

| |

C=O C=O

| |

H - C- OH HO- C-H

| |

HO-C-H H-C-OH

| |

H - C- OH H-C-OH

| |

H- C-OH CH2OH

|

CH2OH

GLUGOSE FRUCTOSE

*carbohydrate formula Cn(H2O)n ----------------- hydrate of carbon

BIOLOGIC IMPORTANCE---------------------------------------------------------------

1- source of energy in the body

2- proteins sparing action of carbohydrate

3- source of energy for CNS is glucose----1-hypoglycaemia---

(damage of the brain)

2-hyperglycaemia

4- add flavour and variety to diet

Q- what are the medical importance of carbohydrate?

Types of carbohydrates

Classifications based on number of sugar units in total chain.

Monosaccharides - single sugar unit

Disaccharides - two sugar units

Oligosaccharides - 2 to 10 sugar units

Polysaccharides - more than 10 units

Chaining relies on ‘bridging’ of oxygen atoms

glycoside bonds

CLASSIFICATION------------------------------------------------

1- monosaccharide (simple sugar) (CH2O)n n=3 or more

This group subdivided into

(a) Depending upon the function group

H |

C=O|

H- C-OH|

H-C-OH|

H-C-OH|

CH2OH

CH2OH |C=O|

HO-C-H|

H-C-OH|

H-C-OH|CH2OH

Aldose Ketose

(B) Depending upon the number of carbon atoms

General formula Aldosugar ketosugar

--------------------------------------------------------------------------

Triose(C3H6O3) Glyceraldehyde Dihydroxyaceton

Tetrose(C4H8O4) Erythrose Erythrulose

Pentose(C5H10O5 ) Ribose Ribulose

Hexose(C6H12O6) Glucose Fructose

H |

C=O|

H- C-OH|

CH2OH

H |

C=O|

H- C-OH |

H-C-OH|

CH2OH

H |C=O|

H- C-OH|

H- C-OH|

H- C-OH|

CH2OH

H |

C=O|

H- C-OH|

H- C-OH|

H- C-OH|

H- C-OH|

CH2OH

triose tetrose pentose hexose

Can be either aldose or ketose sugar.

Examples

H |C=O|

H-C-OH|CH2OH

D-glyceraldehyde D-fructose

triose hexose

aldose ketose

aldotriose sugar ketohexose sugar

CH2OH |C=O|

HO- C-H|

H- C-OH|

H- C-OH|CH2OH

H |C=O|

H- C-OH|

H- C-OH|

H- C-OH|CH2OH

H |C=O|

H- C-OH|

H- C-OH|

HO- C-H|

HO- C-H|CH2OH

Examples

D-ribose L-mannose

pentose, aldose hexose, aldose

aldopentose sugar aldohexose sugar

Q-draw the structure of the carbohydrate?

1- L-glucose

2- L-glyceraldehyde

3- Ribulose

4- D-galactose

5- arabinose

2- Disaccharides: these sugars are yield 2 molecules of the same

or different molecules of monosaccharide on hydrolysis

EXAMPLE Lactose

Milk sugar - dimer of -D-galactose and either

the or - D-glucose.

-LactoseOOH

H HH

H

OH

CH2OH

H

OH

OH OH

HH

H

OH

CH2OH

H

OH

O

-D-galactose -D-glucose

(1 4) linkage, disaccharide.

Sucrose

Table sugar - most common sugar in all plants.

Sugar cane and beet, are up to 20% by mass sucrose.

Disaccharide of -glucose and -fructose.

CH2OH O

CH2OHH

OH H

H OH

H O

OH

H

H

OHH

OH

CH2OH

H

O

(1 2) linkage

Maltose

Malt sugar. Not common in nature except in

germinating grains.

-D-glucose -D-glucose

OH

OH

H

H

H

OH

CH2 OH

H

OH

OH OH

H

H

H

OH

CH2 OH

H

OH

O

-D-glucose and -D-glucose, (1 4) linkage.

3- Oligosaccharides: these sugars are yield 2-10 molecules of

monosaccharide on hydrolysis

EXAMPLE

(Raffinose----------(glucose +fructose + galactose)

4- Polysaccharides: these compounds yield many molecules of

monosaccharide on hydrolysis

General formula (C6H10O5)n

This group are subdivided into two groups

(a) Homopolysaccharide:polymer of the same monosaccharide units

e.g starch , glycogen , inulin , cellulose

Starch

Energy storage used by plants

Long repeating chain of -D-glucose

Chains up to 4000 units

Amylose straight chain

major form of starch

Amylopectin branched structure

Amylose starch Straight chain that forms coils (1 4) linkage. Most

common type of starch.

OH H

H

OHH

OH

CH2OH

H

OH H

H

OHH

OH

CH2OH

H

O O

OH H

H

OHH

OH

CH2OH

H

OH H

H

OHH

OH

CH2OH

H

O O

O

OO

OO

O

O

OO

OO

O

O

OO

OO

O

O

OO

OO

O

Amylopectin starch

Branched structure due to crosslinks.

OHH OHH OHH

OH H

HOH

CH2OH

H

OH H

HOH

CH2OH

H

O O

OH H

HOH

CH2OH

H

OH H

H

OHH

OH

CH2OH

H

O O

OH H

H

OHH

OH

CH2OH

H

OH H

H

OHH

OH

CH2OH

H

O O

OH H

H

OHH

OH

CH2OH

H

OH H

H

OHH

OH

CH2

H

O O

(1 6) linkage

at crosslink

Glycogen

• Energy storage of animals.

• Stored in liver and muscles as granules.

• Similar to amylopectin.

O

O

O

O

O

O

O

O

O

O

O

O

O

O

(1 6) linkageat crosslink

Cellulose

• Most abundant polysaccharide.

• (1 4) glycosidic linkages.

• Result in long fibers - for plant structure.

OH

H

H

OHH

OH

CH2OH

H

OH

H

H

OHH

OH

CH2OH

H

O

O

OH

H

H

OHH

OH

CH2OH

H

OH

H

H

OHH

OH

CH2OH

H

O

O

OH

H

H

OHH

OH

CH2OH

H O

InulinInulin = polymer of fructose

(B) Heteropolysaccharides :polymer of different monosaccharide units

or their derivatives .

Example

1- hyaluronic acid (glucuronic acid + N-acetyl hexosamine )

2- mucopolysaccharide ( hexose + hexosamine)

3- chondroitin ( glucuronic acid+ N- actylgalactosamine + sulphate )

4- heparin (glucuronic acid + glucosamine N- sulphate + sulphate

ester)

Thank you