How does mechanical digestion and chemical digestion take place in the mouth and stomach?

Answer 1

Mechanical digestion is the actual physical break down of food into smaller pieces. One example of this is mastication (chewing) which occurs in the mouth by the teeth, which act to cut and grind food into smaller pieces. This makes them easier to later digest as it increases the SA of the food molecules. A certain type of food is made of lots of different chemicals but certain chemicals are found in the center. The chewing breaks it apart and exposes these chemicals so that they can be broken down quicker/easier. Another form of mechanical digestion is peristalsis; succesive contractions of muscles in the alimentary canal which form a wave of constriction that moves food along. In the stomach, there are three layers of muscle (which is unique as the rest of the alimentary canal only has 2). It has longatudinal, circular and oblique muscle which together contract and relax to form the churning motion which mixes food around. This aids in digestion as it slightly breaks up the food and also increases the contact the food has with enzymes and acids in the gastric juice. Bile salts (which are found in bile secreted from the liver) also act to emulsify large fat globules into smaller fat droplets. Its sort of like how detergent works and it breaks up all molecules and then puts a 'soapy' shield around them so they cant join back together. This increases the SA of the molecule of fat so that enzymes (particulary pancreatic lipase) can act on it and break it down to smaller, simpler forms are body can absorb. Chemical digestion on the other hand, is the chemical break down of foods into smaller pieces. An example of this is how enzymes break them down. In particular, the enzyme salivary amylase is found in our saliva which acts to break down starch into simpler forms (polysaccharides --> dissaccharides). Another form of this digestion is how the HCl acid in the stomach helps to break down food and destroy any microorganisms that accompanied the food.

Answer 2

Mechanical digestion refers to the actual grinding / physical digestion in your mouth where

your teeth cut and MASH up your food. Chemical digestion refers to the enzymes that break up the food chemically, for example, amylase.

or do you mean the science chemical ad mechanical?

Answer 3

In mechanical digestion, the teeth and tongue work to break food down into smaller pieces. A big component of mechanical digestion is chewing. Chemical digestion happens mainly in the small intestine, where digestive enzymes are released to further break down the food particles into their molecular compounds. Once the food has been broken down to this level, all of the nutrients in the intestines are absorbed back into the body.

Answer 4

The chewing motion of the teeth is the mechanical digestion which allows food to be safely swallowed. It is then ready for chemical digestion in the stomach by stomach acids.

Answer 5

Mechanical digestion is chewing the food; chemical digestion is what the various digestive enzymes and stomach acid accomplish.