Carbohydrates — classification (mono - di - polysaccharides), Fischer - Haworth projections, mutarotation, glycosidic bo

4.5.1 · Chemistry › Biomolecules

1. Classification — hydrolysis ke basis par

YE scheme kyun? Hydrolysis glycosidic bond ko todta hai (Section 6). Kitne bonds toot sakte hain, ye batata hai kitne sugar units jude the.

2. Reducing vs non-reducing — ek 20% idea jo bahut kuch explain karta hai

3. Fischer projection — ek 3D sugar ko flat mein draw karna

Figure — Carbohydrates — classification (mono - di - polysaccharides), Fischer - Haworth projections, mutarotation, glycosidic bo

4. Ring formation & Haworth projection

5. Mutarotation — proof ki ring khulti hai

6. Glycosidic bond — sugars ko jodna

Active recall

Recall Khud test karo (answers chhupaao)

Carbohydrate ko define karne wale functional groups kaun se hain? → polyhydroxy aldehyde/ketone.
Glucose mein kaun sa carbon anomeric carbon banta hai? → C1 (pehle wala –CHO).
Sucrose mein mutarotation kyun nahi? → dono anomeric carbons locked hain, ring khul nahi sakti.

What is a carbohydrate, chemically?

Ek polyhydroxy aldehyde ya ketone, ya koi substance jo hydrolyse hokar ek de.

Difference between aldose and ketose?

Aldose mein terminal –CHO hota hai; ketose mein internal ketonic C=O hota hai.

Define monosaccharide.

Wo sugar jo kisi simpler carbohydrate mein hydrolyse nahi ho sakti.

What does a disaccharide give on hydrolysis?

Do monosaccharide units (ek glycosidic bond tuta, +H2O).

What is the anomeric carbon?

Pehle wala carbonyl carbon (glucose mein C1) jo ring closure par ek naya chiral centre ban jaata hai.

Difference between α and β anomer?

Anomeric –OH ki configuration: α neeche point karta hai (CH2OH ke trans), β upar (cis) Haworth mein.

Are anomers enantiomers or diastereomers?

Diastereomers (sirf ek stereocentre par alag, anomeric C).

Define mutarotation.

Sugar solution ki optical rotation ka dheere dheere equilibrium value tak aana, open chain ke through α⇌β interconversion se.

Equilibrium rotation of D-glucose?

+52.7°, ~36% α (+112°) aur ~64% β (+19°) se.

Why is sucrose non-reducing?

Dono anomeric carbons α,β(1↔2) glycosidic bond mein use ho jaate hain, toh koi free –CHO/–C=O nahi.

What links monosaccharides in a glycosidic bond?

Ek sugar ka anomeric –OH doosre ke –OH ke saath condense karta hai, H2O khokar (C–O–C ether linkage).

Fischer rule for horizontal vs vertical bonds?

Horizontal bonds viewer ki taraf point karte hain; vertical bonds door.

Fischer→Haworth conversion rule?

Fischer mein right → Haworth mein neeche; left → upar; D-sugar CH2OH upar point karta hai.

How do you assign D or L?

Sabse neeche wale chiral carbon ko dekho: –OH right par = D, left par = L.

Glycosidic linkage in maltose vs cellulose?

Maltose α(1→4); cellulose β(1→4) glucose–glucose.

Recall Feynman: ek 12-saal ke bachhe ko samjhao

Sugar molecules choti choti chains hoti hain jinka ek chipchipa end hota hai (–CHO). Glucose ki chain itni lambi hai ki uski apni tail mur ke us chipchipe end ko pakad leti hai, ek ring banaati hai. Jab ring snap hokar band hoti hai toh wo do thodi alag tarahon se lock ho sakti hai — unhe "neeche-wala darwaza" (α) aur "upar-wala darwaza" (β) kaho. Paani mein ring chupke chupke khulti aur dobara lock hoti rehti hai, isliye jo jar shuru mein sab "neeche-wale darwaze" wali sugar se bhari thi wo dono ki mix ban jaati hai. Kyunki do darwaze roshni ko alag alag modein, roshni-modne wala number dheere dheere drift karta hai aur settle ho jaata hai — yahi mutarotation hai. Bade sugars banane ke liye, ek ring ka special darwaza-corner doosri sugar se haath milata hai aur ek boond paani bahar phenk deta hai; yahi haath-milaana glycosidic bond hai.

Connections

Glucose — structure and reactions
Disaccharides — sucrose, maltose, lactose
Polysaccharides — starch, cellulose, glycogen
Optical isomerism and specific rotation
Hemiacetal and acetal formation
Stereochemistry — anomers, epimers, enantiomers