Biochemistry: Carbohydrates, Classification, Sources and Uses

Carbohydrates are macromolecules defined as Polyhydroxy aldehydes or ketones. They have general formula Cn(H2O)n.

Synthesis

Plants synthesize carbohydrates through photosynthesis. In this process plants convert carbon dioxide and water into glucose in the presence of sunlight and green pigment chlorophyll.

Classification: Carbohydrates are classified as

1. Monosaccharaides

2. Oligosaccharides

3. Polysaccharides

1.Monosaccharide

The carbohydrates which cannot be further hydrolyzed. These are also called simple sugars. They consist of 3 to 9 carbon atoms. They are further classified as trioses, tetroses, pentoses, hexoses, and so on depending on number of carbon atoms in their molecules, The important monosaccharaides are hexoses like glucose and fructose, etc.

Properties

• Monosaccharaides are white crystalline solids.

• They are sweet in taste and soluble in water

• They cannot be hydrolyzed.

• They are reducing in nature, therefore, these are called reducing sugars.

2.Oligosaccharides

The carbohydrates which upon hydrolysis give 2 to 9 units of monosaccharide or simple sugars are called oligosaccharides. • They are further classified as disaccharides, trisaccharides, tetrasaccharides, etc., depending upon the number of monosaccharide units they produce on hydrolysis. Examples: sucrose. • On hydrolysis, sucrose produces one unit of glucose and one unit of fructose.

Properties

• These carbohydrates are white, crystalline solids easily soluble in water.

• They are also sweet in taste.

• They may be reducing or non-reducing

Question What is the main difference between glucose and fructose?

Answer. Glucose is a pentahydroxy aldehyde while fructose is pentahydroxy ketone having the open chain structures as follows and general formula C₆H₁₂0₆.

3. Polysaccharides

The carbohydrates which upon hydrolysis give10 to 1000 monosaccharide units or simple sugars are called oligosaccharides. Example: starch, cellulose.

Properties

•They are amorphous solids.

•They are tasteless and insoluble in water.

• They are non reducing in nature.

Question. What is the dextrose sugar? Give examples.

Answer.

The monosaccharide which can rotate the plane of plan polarized light to right (clockwise). They are called dextrorotatory or dextrose sugar. For example; glucose, glactose, mannose etc.

Question: Explain the sources and uses of Carbohydrates.

Answer.

Sources and Uses of Carbohydrates

Carbohydrates are the most abundant class of carbon containing compounds. There are various sources and uses.

Sources of monosaccharaides or simple sugars:

Glucose, fructose and galactose are found in fruits, vegetables, honey and cereals.

Sources of Disaccharides

Sucrose is found in sugar beet, sugar cane, and fruits. .Lactose is present in milk and dairy products. Maltose, is found in cereals.

Sources of Polysaccharides

Starch is found in cereal crops; wheat, barley, maize, rice, etc. Cotton is pure cellulose.

Uses

1.Carbohydrates in form of glucose transport energy both in plants and animal. In human body, 1 g of glucose produces 15.6 KJ/mole energy.

2. Carbohydrates are source of food for most of organism.

3. Carbohydrates are structural material of plants

4. Cellulose (fibers) is found bran, whole meal bread, vegetable and fruits etc,

5. Cellulose absorbs toxic material in food that can harm the human body.

6. It lowers the cholesterol level and control the blood pressure.

7. Sucrose is used as table sugar.

8. Glucose is stored in animal in muscles and liver in the form of glycogen which serves as source of energy for long time.

9. Glucose is sstored in plant in the form of starch,

10. Starch is used in preparation of rectified spirits.

11.Sarch is used as adhesives.

Comments

Class 9 Chemistry Notes for Federal Board

Class 9 Chemistry Notes for Federal Board Introduction Class 9 Chemistry notes for the Federal Board have been written according to the National Curriculum 2006. It develops various skills such as questioning, observations, predicting, measuring, classifying, designing experiments, analyzing and interpreting the data. among students. We have made these notes very simple. After reading these notes, students can easily understand all topics. Students can answer all types of questions including essay type, short and multiple choice, self assessments and think tank. We have also solved exercises according to the Federal board examination pattern. Students, after going through 9th class chemistry notes can get maximum marks in their exams. They can lay down a strong foundation of scientific knowledge among students. In future, notes for class 9 will be available in pdf format. Students will be able to note pdf free download very soon. Students will have access to these notes in a mobi

Class 10 Chemistry Notes for Federal Board

Class 10 Chemistry Notes for Federal Board Introduction Class 10 Chemistry Notes for Federal Board have been written according to the National Curriculum 2006. These notes will make students able to learn topics by their own. 10th class notes for all chapters are very and easy to understand. After studying these notes, students will become confident to answer all type of questions. Chemistry notes for class 10 provide solution to all kinds of questions including essay type, short and multiple choice, self assessments and think tank. These notes also contain all past papers of reduced syllabus as well as complete syllabus. Soon, students will have access to 10th class chemistry notes in Urdu pdf download form. We are also working hard to provide all chemistry notes in pdf format and student will be able to download these notes. We also trying to upload video lectures about class 10 chemistry. Don't forget, you can test your chemistry by using online test. Furthermore, you highl

Theories of Covalent Bonding and Shapes of Molecules: MCQs

chemicalAlgebra 1. The bond energies of F 2 , Cl 2 , Br 2 and I 2 are 37, 58, 46 and 36 Kcal, respectively. The strongest bond is formed in A) F 2 B) Cl 2 C) Br 2 D) I 2 ... Answer is B) Description: The bond energy is proportional to bond length. So, the bond strength of Cl 2 is higher. show Answer 2. The percentage of ionic character of bond between two atoms is calculated from the difference between their A) Ionic B) Electronegativities C) Electron affinities D) Ionization energies ... Answer is B) Description: The percentage of ionic character depends upon the difference of E.N. difference between the bonded atom. Greater the E. N. difference, greater the ionic character and hence greater the bond energy show Answer 3. The geometry of PF 5 molecule is A) Planer B) Square planer C) Trigonal pyramidal D) Tetrahedral ... Answer is C) Description: As i

Chemistry

T he Federal Board of Intermediate & Secondary Education (FBISE) is an autonomous body that conducts the examinations in the institutions affiliated with it in Pakistan as well as abroad. Punjab government has ten boards of Intermediate & Secondary Education including Bahawalpur Board, D.G. Khan Board, Faisalabad Board, Gujranwala Board, Lahore Board, Multan Board, Rawalpindi Board and Sargodha Board and each board conducts exams independently. Federal Board generally follows the international norms and standards. Federal Board paper pattern is quite tricky and similar to O-Level and A Level formats. These questions need conceptual approach to be solved. Punjab board’s Paper pattern is comparatively easy up to some extent. We are currently focusing on the subject of Chemistry for all classes affiliated with Federal Board ( IX , X , XI , XII ) and Punjab Board ( XI XII ). We intend to extend it to all subjects in future. After reading All Student Notes, studen

Basic Definitions| Matter, Substance, Element, Compound. Mixture, Homogeneous mixture and Heterogeneous mixture Examples (for Grade - 9 students)

Basic Definitions| Matter, Substance, Element, Compound. Mixture, Homogeneous mixture and Heterogeneous mixture Examples (for Grade - 9 students) Question: Define following terms: Matter Substance Element Compound Mixture Homogeneous mixture Heterogeneous mixture Answer Matter: Matter can be anything that occupies space (volume) and has mass. Example, book, table, walls, chairs, plants, animal, etc. Substance: Substance is a matter that has a particular set of characteristics that differ from the characteristics of another kind of matter. For example, oxygen, water, carbon monoxide, carbon dioxide, urea, glucose, common salt etc are different substances. Element: A substance that cannot be converted to other simpler substances is known as an element. or A substance which has all atoms of same atomic number is called element. For example substances like oxygen, hydrogen, iron, copper, aluminum etc. are elements. Compound: A compound is a pure substance that co

Experimental Techniques in Chemistry

Analytical Chemistry: The branch of chemistry that deals with the quantitative and qualitative analysis of substances is called Analytical Chemistry. Question 2.1: What is difference between quantitative and quantitative analysis? What are various steps involved in quantitative analysis? Answer: Qualitative analysis: The analysis in which elements are identified is called qualitative analysis. Quantitative analysis: The analysis in the form of which relative amounts of elements are determined is called quantitative analysis. There are four main steps involved in quantitative analysis. 1. Obtaining a sample for analysis 2. Separation of desired constituent 3. Measurement and calculations of results 4. Drawing conclusions from analysis Question 2.2: Define filtration. How do we select the filter media? Answer: The process of separating solids or suspended particles from liquids by using a filter medium is called filtration. Question 2.3: Describe filt

Alkyl halides

The compounds in which one hydrogen atom of alkane is replaced by a halogen atom is called alkyl halide. Alternatively, The halogen derivatives of alkanes with general formula R-X are Halide called alkyl halide. For example CH4 ( Alkane ) CH3-X ( Alkyl halide ) X = F, Cl, Br and I Table Of Contents Types Mono, di, tri or poly haloalkane depending upon the number of halogen atom. For example C lassification of Alkyl Halides Alkyl halides can be classified as primary, secondary and Tertiary alkyl halides. 1. Primary Alkyl Halides The alkyl halides in which a halogen atom is bonded with primary carbon is called primary alkyl halide. Primary carbon is the carbon that is attached one or no carbon atom. The Secondary Alkyl Halides The alkyl halides in which a halogen atom is bonded with secondary carbon are called secondary alkyl halide. Secondary carbon is the carbon that is attached with two carbon atoms. For example

CHAPTER # 15 ORGANIC COMPOUNDS

ORGANIC COMPOUNDS Modern definition. C ompounds of carbon, hydrogen and their derivatives, are called organic compounds. For example, CH 4 , CH 3 Cl etc. Contents Sources of organic Compounds: Following are the main sources of organic compounds: i. Fossil fuels or Fossil remains. ii. Plants and Natural product iii. Partial &Total Synthesis iv. Fermentation and Biotechnology Fossil fuels or Fossil remains: The main sources of fossil fuels or fossil remains are: a. coal b. petroleum c. gas a. Coal: Coal is one of the organic compounds. Coal major source of into coke, and coal law" on pyrolysis Com can be converted destructive distillation. More than 200 organic compounds" have been directly isolated from coal tar, which are used. in ...drug. dyes, other. preparation of perfumes.. photographic developers and. b. Petroleum: Petroleum Sticky Liquid ground in that is block Thick seeps out of the some part of world. It is Complex mixtur

Shielding Effect (Grade 9 Students) and its trend in Periodic Table.

Question: What is shielding effect? Give its trends in the periodic table. Answer . Shielding Effect The decrease in force of attraction between nucleus and valence electrons due to presence of inner shell electrons is called shielding effect. It is also known as screening effect. It increases with increase in inner shell electrons. For example, Mg has greater shielding effect than Be. This is because Mg has eight more inner-shell electrons than Be. Trend in Periodic Table In period As we move from left to right in a period, shielding effect remains constant. Reason is that the number of inner shell electrons remains constant along the period. In group As we move from top to bottom in a group, shielding effect increases. This is due to fact that the number of inner shell increases and hence, inner shell electrons also increase. For example, Na has greater shielding effect than Li because of eight more inner shell electrons than Li. Example 3.5 Identi

Class 9 Electrochemistry MCQs and Answers with explanation

1. In which of the following changes, the nitrogen atom is reduced? a) N 2 to NO b) N 2 to NO 2 c) N 2 to NH 3 d) N 2 to HNO 3 ... Answer is b) Explanation: Oxidation number of an elemnet in free state is zero. So Oxidation No. of N 2 = 0 Calculate oxidation No. of nitrogen in each compound. Option a) Let, oxidation No. of N in NO is X. Sum of oxidation numbers of all atoms present in a neutral compound is zero. Oxidation No. of N + (Oxidation No. of O ) = 0 X-2 = 0 X = +2 X = +2 Oxidation No. of N in NO 2 is +2 Option b) Let, oxidation state of N in NO 2 is X. Sum of oxidation numbers of all atoms present in a neutral compound is zero. Oxidation No. of N + 2(Oxidation No. of O ) = 0 X + 2(-2) = 0 X -4 = 0 X = +4 Oxidation No. of N in NO 2 is +4 Option c) Let, oxidation state of N in NH 3 is X. Sum of oxidation numbers of all atoms present in a neutral compound is zero. Oxidation No. of N + 3(Oxidation No. of H )

All Students Notes

Search This Blog