• AglaSem
  • Schools
  • Admission
  • Career
  • CutOffs
  • News
  • Hindi
  • Mock Test
  • Docs
  • ATSE
aglasem
  • CBSE
    • Date Sheet
    • Question Papers
    • Sample Papers
  • ICSE / ISC
  • State Boards
    • Date Sheet
    • Result
  • NCERT
    • NCERT Books
    • NCERT Solutions
    • NCERT Exempler
    • Teaching Material
  • Mock Tests
  • Study Material
    • Notes
  • Olympiads
    • ATSE
    • KVPY
    • NTSE
    • NMMS
  • School Admission
  • Entrance Exams
    • JEE Main
    • NEET
    • CLAT
  • Students Guide
    • Careers Opportunities
    • Courses & Career
    • Courses after 12th
  • Others
    • HC Verma Solutions
    • Teaching Material
    • Classes Wise Resources
    • Videos
    • Resources
No Result
View All Result
aglasem
  • CBSE
    • Date Sheet
    • Question Papers
    • Sample Papers
  • ICSE / ISC
  • State Boards
    • Date Sheet
    • Result
  • NCERT
    • NCERT Books
    • NCERT Solutions
    • NCERT Exempler
    • Teaching Material
  • Mock Tests
  • Study Material
    • Notes
  • Olympiads
    • ATSE
    • KVPY
    • NTSE
    • NMMS
  • School Admission
  • Entrance Exams
    • JEE Main
    • NEET
    • CLAT
  • Students Guide
    • Careers Opportunities
    • Courses & Career
    • Courses after 12th
  • Others
    • HC Verma Solutions
    • Teaching Material
    • Classes Wise Resources
    • Videos
    • Resources
No Result
View All Result
aglasem
No Result
View All Result

CBSE Class 12 Chemistry Notes: Biomolecules – Introduction

by Neepur Garg
April 22, 2019
in 12th Class, Class Notes
Reading Time: 2min read
0
635
SHARES
0
VIEWS
Share on FacebookShare on Twitter

Old Definition

The group of compounds known as carbohydrates received their general name because of early observations that they often have the formula Cx(H2O)y – that is, they appear to be hydrates  of carbon.

Limitations of the old definition:The above definition could not survive long due to the following reasons:

(i) A number of compounds such as rhamnose, (C6H12O5) and 2-deoxyribose (C5H10O4) are known which are carbohydrates by their chemical behaviour but cannot be represented as hydrates of carbon.

(ii) There are other substances like formaldehyde (HCHO, CH2O) and acetic acid [CH3COOH, C2 (H2O)2] which do not behave like carbohydrates but can be represented by the general formula, Cx(H2O)y.

New definition

Carbohydrates are defined as polyhydroxy aldehydes or polyhydroxy ketones or substances which give these on hydrolysis and contain at least one chiral carbon atom. It may be noted here that aldehydic and ketonic groups in carbohydrates are not present as such but usually exist in combination with one of the hydroxyl group of the molecule in the form of hemiacetals and hemiketals respectively.

« Click Here for Index Click Here for Next Topic »

CBSE Class 12 Chemistry Biomolecules All Topic Notes CBSE Class 12 Chemistry All Chapters Notes

To get fastest exam alerts and government job alerts in India, join our Telegram channel.

Tags: CBSE NotesClass 12 NotesClass 12thFree Notes

Neepur Garg

Related Posts

12th Class

Maharashtra Board HSC Time Table 2021 – Check for 12th Commerce, Arts, Science

KVPY 2020
11th Class

KVPY 2020 – Kishore Vaigyanik Protsahan Yojana Tentative Answer Key (Out), Result

10th Class

IARCS Olympiads: Indian Association for Research in Computing Science

12th Class

MP Board Question Paper Class 12th 2020 for Travel and Tourism

Next Post

Special Scholarship Program (SSP) for Doctoral Applicants

Discussion about this post

Registration Open!!

  • UPES Dehradun Application 2021
  • Manav Rachna University Application 2021
  • DIT University 2021 Application
  • NIIT University Admission 2021

Class Wise Study Material

  • Class 1
  • Class 2
  • Class 3
  • Class 4
  • Class 5
  • Class 6
  • Class 7
  • Class 8
  • Class 9
  • Class 10
  • Class 11
  • Class 12
  • Disclaimer
  • Terms of Use
  • Privacy Policy
  • Contact

© 2019 aglasem.com

No Result
View All Result
  • CBSE
  • ICSE / ISC
  • State Board
  • NCERT
  • Mock Test
  • Study Material
  • Olympiads
  • Schools Admission
  • Entrance Exams
  • Student Guide
  • HC Verma Solutions
  • Videos

© 2019 aglasem.com

IIAD 2021 Registration Open Click Here