Chemistry 121 Winter 17 - latech.eduupali/chem121/slides/GHW#8-Questions$Slides.pdf · February 23, 2017: Make Up Exam: Chapters 12-22) ... Questions & Slides Carbohydrates CHEM 121

Introduction to Organic Chemistry and Biochemistry

Instructor Dr. Upali Siriwardane (Ph.D. Ohio State)

E-mail: [email protected]

Office: 311 Carson Taylor Hall ; Phone: 318-257-4941;

Contact me trough e-mail if you have questions

Online Tests on Following days

December 16, 2016: Test 1 (Chapters 12-13)

January 23, 2017 : Test 2 (Chapters 14-16)

February 10, 2017 : Test 3 (Chapters 17-19)

February 22, 2017 : Test 4 (Chapters 20-22)

February 23, 2017: Make Up Exam: Chapters 12-22)

Chemistry 121 Winter 17

1

Chapter 18 and GHW#8 Questions & Slides

Carbohydrates

CHEM 121 Winter 2016 2

Chapter 18: Carbohydrates

CHEM 121 Winter 20163

18-1 Biochemistry—An Overview

18-2 Occurrence and Functions of Carbohydrates

18-3 Classification of Carbohydrates

18-4 Chirality: Handedness in Molecules

18-5 Stereoisomerism: Enantiomers and Diastereomers

18-6 Designating Handedness Using Fischer Projection Formulas

18-7 Properties of Enantiomers • 18-8Classification of Monosaccharides

18-9 Biochemically Important Monosaccharides

18-10 Cyclic Forms of Monosaccharides

18-11 Haworth Projection Formulas

18-12 Reactions of Monosaccharides

18-13 Disaccharides

18-14 Oligosaccharides

18-15 General Characteristics of Polysaccharides

18-16 Storage Polysaccharides

18-17 Structural Polysaccharides

18-18 Acidic Polysaccharides

18-19 Dietary Considerations and Carbohydrates

18-20 Glycolipids and Glycoproteins: Cell Recognition

What is BiochemistryBiochemistry is the study of the chemical processes occurring in living matter.

Chemical Processes

Involving carbohydrates (chapter 18)

Involving Lipid (chapter 19)

Involving Proteins (chapter 20)

Involving Genetics (RNA &DNA) (chapter 22)

Involving Vitamins & Minerals (chapter 21)


CarbohydratesOrganic compounds containing many -OH groups (polyhydroxy), and aldehydes or ketones functional groups. They are called sugars.Aldoses: Aldehyde sugars are called aldoses.Ketoses: Ketone sugars are called ketoses.Formula for Cabohydrates: CnH2nOn or Cn(H2O)n (hydrates of C)n= number of atomsMonosaccharides

They consist of one sugar containing 3,4,5,6 and 7 carbon atoms

Disaccharides Polysaccharides


Drawing Sugar Molecules

CHO

OHH

HHO

OHH

OHH

CH2OH

Glucose

CH2OH

O

HHO

OHH

OHH

CH2OH

Fructose

Aldehyde

Polyhydroxyaldehyde

Ketone

Polyhydroxyketone

Linear structure-Fischer projection


hydroxy

Types of sugars

Number fo carbon atoms

• Triose sugar units containing three carbon atoms

• Tetroses sugar units containing four carbon tomsa

• Pentoses sugar units containing five carbon atoms

• Hexoses sugar units containing six carbon atoms



CH 3CH 2CH 2CH 3 CH 3CHCH 3

CH3

CH 3CH 2CH 2 CH 3CH CH 3

Br Br

CH 3CH 2OH CH 3OCH 3

CH3

HHH

CH3H

C CH

Br

H

BrC C

H

Br

Br

H

CH3

H H

CH3

H H

CO2H

CH3

H OHC

CO2H

CH3

H O HC

Constitutional Isomers

Positional (Chp. 12)

Skeletal (Chp. 12)

Enantiomers (Optical) (Chp. 16)

Functional (Chp. 14)

StereoisomersConformational (Chp.12)Geometric (Chp. 13)


Chirality: Handedness in Molecules

Most monosaccharaides exist in two forms: a “left handed” and “right handed” form due to chiral carbon atoms

CHO

HO H

C

CH OH2

CH OH2

H

CHO

HO

CHO

H

C

CH OH2

OH

CH OH2

H

CHO

OH


D isomers L isomers

Chirality and Optical Activity

Polarimeter assigns D and L isomers

D-rotated to rightL-rotates to left

L D

L isomers D isomers


Cyclic anomeric forms: a- and b- forms

Fischer structure Haworth structures

ALDEHYDE sugar or aldoses + alcohol --- hemiacetal (cyclic ring)


1) Give names of the following carbohydrates. Identify the chiral carbon atoms with *


2) Circle the correct classifications that apply to the following carbohydrates.


2) Circle the correct classifications that apply to the following carbohydrates.


2) Complete the names, circle carbon atom numbers of the OH group which is on the left and the structure for

following aldohexoses.








2) Complete the names, circle carbon atom numbers of the OH group which is on the left and the Fisher

Projection structure for following aldohexoses.


How you get cyclic hemiacetal form of the hexose sugars pyran with b- and a

anomeric forms.


b-D-fructofuranosea-D-glucopyranose

Haworth Projection Formula-cyclic

How you get cyclic hemiacetal form of the ketohexose sugar D-fructofuranose with b-anomeric.


b-D-fructofuranose

D-fructose

Fisher Projection Formula-Linear Haworth Projection Formula-cyclic

How you get cyclic hemiacetal form of the ketohexose sugar D-glucopyranose with b-anomeric.


Fisher Projection Formula-Linear

Haworth Projection Formula-cyclic

D-glucose

b-D-glucopyranose

4) a) Complete the following diagram to get the cyclic hemiacetal form of the aldohexose sugar D-glucopyranose with b-anomeric configuration.


4)

b) Draw the structure of b-D-mannopyranose


4) c) What is the difference between pynanose and furanose types of sugars?

d) What is the difference between a and bforms of cyclic hemiacetal forms of sugars?


5) Convert the hemiacetal cyclic structures (Haworth Projections) for following carbohydrates to Fischer Projections.

a) Use the procedure we used in problem 4 to get linear form of the hexoketose sugar from cyclic D-fructofuranose with a-anomeric


5)b) Use the procedure we used in problem 4 to get linear form of the hexoaldose sugar from cyclic D-sugarpyranose with b-anomeric


Glycosidic bonds

Glycosidic bond- covalent bond between a hemiacetal or hemiketal and an alcohol.


DisaccharidesLinked by glycosidic bond.


Glucose +Glucose -> (a-1-4) maltoseGlucose +Glucose -> (a-1-4)

(Maltose)

Galactose+Glucose -> (b-1-4) lactose

a) Starch:

b) Amylopectin:

c) Glycogen:


Starch and Amylopectin (Glycogen)


Cellulose

6) What are the following? What is/are glucosidic linkage found in them?

d) Cellulose


What carbohydrates are found in them?


The glycemic index is a system that measures how quickly a specific food can raise your blood sugar levels

Fiber-rich foods

7) Answer following question about glycosidic bond of the di-, oligo- and poly-saccharides.a) Name of the following o-glucoside


8)b) Name of the following N-Glycoside

c) Name of the following O-glucoside.


8)d) The following is a part of a cellulose polymeric chain. What is the type of glucosidiclinkage?


Purines and Pyrimidines: DNA Bases


DNA

RNA

DNA

8)e) What is DNA? Describe the components.


Nucleic Acidsphosphate-group+pentose-sugar+Base

D-Ribose D-deoxyribose

• Deoxypentose sugar or D-deoxyribose: ribose-derivative with an oxygen missing on C-2.


Nucleic Acids

Bases

Purines pyrimidinesCHEM 121 Winter 2016 40

DNA-Deoxyribo-Nucleic Acid



8)f) What is RNA? Describe the components.


Documents

Chemistry 121 Winter 17 - latech.eduupali/chem121/slides/GHW#8-Questions$Slides.pdf · February 23, 2017: Make Up Exam: Chapters 12-22) ... Questions & Slides Carbohydrates CHEM 121