List digestive enzymes and their substrates
4.1.8· Biology › Digestive System
WHAT is a digestive enzyme?
Naam usually substrate + suffix -ase batata hai:
- Amylase → amylum (starch) par kaam karta hai
- Protease → proteins par kaam karta hai
- Lipase → lipids (fats) par kaam karta hai
- Nuclease → nucleic acids par kaam karta hai
The Four Substrate Families (80/20 core)
Sirf chaar food macromolecules hain jinke baare mein sochna hai. Har ek ke liye enzyme, kahan kaam karta hai, aur kya banata hai — yeh seekho.
1. Carbohydrates (starch → glucose)
| Enzyme | Made by | Site | Substrate → Product |
|---|---|---|---|
| Salivary amylase (ptyalin) | Salivary glands | Mouth | Starch → maltose |
| Pancreatic amylase | Pancreas | Small intestine | Starch → maltose |
| Maltase | Small intestine | Small intestine | Maltose → glucose + glucose |
| Sucrase | Small intestine | Small intestine | Sucrose → glucose + fructose |
| Lactase | Small intestine | Small intestine | Lactose → glucose + galactose |
2. Proteins (protein → amino acids)
| Enzyme | Made by | Site | Substrate → Product |
|---|---|---|---|
| Pepsin | Stomach (gastric glands) | Stomach | Proteins → peptides |
| Trypsin | Pancreas | Small intestine | Proteins/peptides → smaller peptides |
| Chymotrypsin | Pancreas | Small intestine | Proteins/peptides → smaller peptides |
| Peptidases (erepsin) | Small intestine | Small intestine | Peptides → amino acids |
3. Fats (lipids → fatty acids + glycerol)
| Enzyme | Made by | Site | Substrate → Product |
|---|---|---|---|
| Lingual lipase | Tongue glands | Mouth/stomach | Fats → fatty acids + glycerol (thodi si matra) |
| Pancreatic lipase | Pancreas | Small intestine | Emulsified fats → fatty acids + glycerol |
4. Nucleic acids
| Enzyme | Made by | Site | Substrate → Product |
|---|---|---|---|
| Nucleases (DNase, RNase) | Pancreas | Small intestine | DNA / RNA → nucleotides |
HOW to reconstruct the whole table from scratch (Derivation logic)
Tum 15 rows yaad nahi karte — tum unhe 3 rules se derive karte ho:
- Har polymer ko ek starter + ek finisher chahiye. Bade cuts pehle hote hain (mouth/stomach), final cuts monomers mein small intestine mein hote hain.
- Enzyme ka optimum pH organ se match karo. Acidic stomach ⇒ pepsin/lingual lipase. Neutral/alkaline intestine ⇒ pancreatic + intestinal enzymes.
- Pancreas = master gland. Yeh har type ka ek secrete karta hai: amylase, trypsin/chymotrypsin, lipase, nucleases — sab small intestine mein.
Common Mistakes (Steel-manned)
Recall
Recall Flashcards — pehle try karo, phir reveal karo
#flashcards/biology Mouth mein starch kaunsa enzyme digest karta hai? ::: Salivary amylase (ptyalin), starch → maltose Maltase ke maltose par kaam karne ka final product? ::: Do glucose molecules Stomach mein protein digest karne waala enzyme aur uska optimum pH? ::: Pepsin, optimum pH ~2 (acidic) Do pancreatic proteases? ::: Trypsin aur chymotrypsin Fats digest karne waala enzyme aur pehle kya hona chahiye? ::: Lipase; bile ko pehle fat emulsify karna chahiye Complete fat digestion ke products? ::: Fatty acids + glycerol Sucrase sucrose ko kismein todta hai? ::: Glucose + fructose Lactase lactose ko kismein todta hai? ::: Glucose + galactose DNA/RNA kaunsa enzyme type digest karta hai aur kahan? ::: Nucleases (DNase/RNase), pancreas se, small intestine mein Kya bile ek enzyme hai? ::: Nahi — yeh ek emulsifier/detergent hai, catalyst nahi Poori digestion ki general chemical reaction ko kya kehte hain? ::: Hydrolysis (paani se bonds todna) Har food type ka ek enzyme kaunsi gland secrete karti hai? ::: Pancreas
Recall Feynman: ek 12-saal ke bachche ko samjhao
Socho tumhara khaana lambi LEGO chains se bana hai — itni badi ki gut wall ke tiny doors se nahi guzar sakti. Digestive enzymes chote scissor-workers hain. Amylase starch chains kaatta hai, pepsin aur trypsin protein chains kaatte hain, lipase fat kaatta hai, aur nucleases DNA kaatte hain. Har worker sirf apni type ki chain kaatta hai. Woh chain ko paani mein dabaate hain taaki ek link toote (yahi hydrolysis hai). Bile koi scissor nahi hai — yeh soap ki tarah hai jo ek badi grease blob ko tiny drops mein toda deta hai taaki fat-scissors tak pahunch sake. Ek baar sab kuch single LEGO bricks (glucose, amino acids, fatty acids) mein kat jaaye, toh yeh doors se guzar kar blood mein chale jaate hain.
Connections
- Hydrolysis and Condensation Reactions — har -ase ke peeche ki chemistry
- Enzyme Action and Optimum pH — WHY pepsin ≠ trypsin location
- Structure of the Small Intestine — jahan final digestion aur absorption hoti hai
- Bile and Emulsification — non-enzyme helper
- Absorption of Nutrients — monomers ke saath aage kya hota hai
- Pancreas and its Secretions — master enzyme gland