DIGESTION — WHAT IS REALLY HAPPENING?

Digestion is your body breaking giant food molecules into tiny molecules using acid, enzymes, muscles, electric signals, and special organs.

Food is made of giant chains :

• proteins

• starch

• fats

Your body can’t use giant chains .So it uses protein-scissors called enzymes.

👄 MOUTH — FIRST BREAK

Your teeth break food into small pieces.Saliva has amylase, a tiny scissor that clips long starch chains into small sugar pieces.

🧵 ESOPHAGUS — MUSCLE WAVE

The tube squeezes in waves.This wave is called peristalsis . It pushes food like toothpaste in a tube.

🔥 STOMACH — ACID + PEPSIN

Your stomach fills with hydrochloric acid, very strong.This acid unfolds proteins (like opening a tangled ball of wool).

Then comes pepsin.Pepsin is a protein-scissor that cuts these unfolded proteins into medium-size chunks called peptides.

So stomach =acid opens protein pepsin cuts protein

The stomach turns food into a soft soup called chyme.

🧪 SMALL INTESTINE — DEEPEST PART

This is where almost everything important happens.

The small intestine is like a long soft tunnel full of tiny fingers (villi).Each villus has even smaller bumps (microvilli).These make a huge surface so food molecules easily pass into blood.

🔹 ACCESSORY ORGANS HELP HERE

These organs do not touch the food, but they send powerful chemicals:

🧨 1. PANCREAS — THE ENZYME FACTORY

The pancreas makes super-enzymes:

• Trypsin

A very powerful protein cutter.Pepsin only makes medium pieces.Trypsin cuts those medium pieces into tiny amino acids your body can use.

Trypsin works only in the intestine because it needs alkaline (not acidic) juice.

• Lipase

Cuts fats into fatty acids.

• Pancreatic amylase

Finishes cutting starch into tiny sugar molecules.

• Nucleases

Cut DNA/RNA in food into nucleotides.

Pancreas also makes bicarbonate, a chemical that stops the strong acid from hurting the intestine.

🟢 2. LIVER — THE CHEMICAL LAB

The liver is like a giant science lab.

It makes bile, a green liquid.Bile does not digest food—it breaks big fat blobs into tiny drops.This is emulsification . Now lipase can cut fats easily.

The liver also stores sugar and cleans your blood.

🟡 3. GALLBLADDER — THE BILE STORAGE

It stores bile like a small bag.When you eat fats, it squeezes and squirts bile into the intestine.

🧊 ABSORPTION

After enzymes cut food into tiny molecules:

• glucose• amino acids• fatty acids .They slip through the villi into blood.

Glucose goes to mitochondria → becomes energy.Amino acids → build muscles and enzymes.Fats → make membranes and hormones.

💧 LARGE INTESTINE — WATER WORLD

Only water and fibres are left.The large intestine pulls water back.Bacteria living here eat fibres and make vitamins like vitamin K.

🚽 END

Leftover bits that cannot be used are pushed out.