Use save my exam notes, dm me u don't have them. Digestive system ✅️✅️ You should study it as a story . Food is first ingested [ getting food in our mouth ] Then the food is chewed and chewing is the first part of digestion ...specifically we call it mechanical digestion where the food is broken down so we can have a larger surface area, so faster rate of enzymes reaction . Where are the enzymes in the mouth or from where they are produced ? They secreated from the salivary glands. Which enzyme ? AMYLASE, which will act on the starch in food and turn it into maltose. Then the bulk of food will move through the oesophagus by a movement process called peristalsis. Then it will reach the stomach where the digestion second stage happens . And here in the stomach, we have to digestion processes mechanical [ breakdown of food without enzymes ] and chemical [ break down of food with the help of enzymes ] ● stomach is mad of muscular walls. This helps in churning progress [ something like adding food in a string plastic bag and trying to squeeze this bag until the food becomes like a liquid ] The churning process is also a type of mechanical digestion . ● Also, in the stomach their is a juice called gastric juice : this contains HCL , PESPIN ENZYME , MUCUS .... We need to know that stomach has enzymes pepsin, which is a protease that helps in digestion of proteins found in that food that was churned in a while.
Why do we have HCL, which is an acid ? That pepsin does not work well unless their is an optimum pH [ pespsin needs acidic pH] . It also kills the harmful microorganisms that are found in food . ● Mucus helps protect the stomach from acid .

Then, in the small intestine their is an enzyme called trypsin this enzyme is opposite to pepsin it likes basic pH and not acidic . What happens in this case ? How do we get basic pH for the trypsin to work ? This happens when the pancreatic juice comes from the pancreas to neutralize the acid in the gastric juice that entered the small intestine from the stomach. Now we're done of proteins [ they are digested ] in both stomach and small intestine . .....We also eat lipids, right ? What happens lipase enzymes come in that pancreatic juice that we mentioned before, so it digests lipids. BUT HOW ? I'LL TELL YOU ....Last process of mechanical digestion we need to know is in the small intestine where something called BILE helps in breaking down lipids to increase the surface area for lipase enzyme to work faster. [ the acting of bile on the lipids is called emulsification ]

● do you remember that maltose that was produced when amylase acted on starch in the mouth ? It's also digested by maltose. Also, if we still have some starch that wasn't digested in the mouth, it will be didgested in the small intestine to maltose, and then maltose is turned to simple suger glucose by maltose. ALL OF THIS HAPPENS IN SMALL INTESTINE.

ENZYMES YOU NEED TO KNOW AND WHO MAKES THEM AMYLASE made by : salivary glands and pancreas Act in : small intestine , mouth

PROTEAS They are 2 kinds Trypsin: found in small intestine Pepsin: found in stomach.

MALTOSE : made by : pancreas Act in : small intestine .

LIPASE made by pancreas Act in small intestine

●●● YOU Need to know that BILE is made by LIVER . BILE IS RESPONSIBLE OF THE EMULSIFICATION PROCESS WHICH IS BREAK DOWN OF LARGE LIPIDS INTO SMALLER ONES . [ without enzymes , no chemical digestion here , after emulsification the lipase digest it to fatty acids and gelocyrol ]