Advertisements
Advertisements
प्रश्न
Answer in detail.
You had eaten bread in the morning. Starting from the mouth, explain how it is digested?
Advertisements
उत्तर
Bread contains starch. The digestion of starch starts in the mouth. When we chew the bread, saliva gets mixed with it. It softens the food. Saliva is secreted by salivary glands. Saliva contains the enzyme salivary amylase (ptyalin) which acts on starch to convert it into maltose
starch \[\ce{->[salivary][amylase]}\] maltose.
After chewing, the food is swallowed into the pharynx. No further digestion takes place in the pharynx. From here the food moves in to the oesophagus, by peristaltic movements it is pushed in to the alimentary canal. In the small intestine (duodenum) rest of the starch is broken down into smaller units by pancreatic amylase. Further Maltose is changed into glucose by maltose in the small intestine (ileum).
APPEARS IN
संबंधित प्रश्न
Fill in the blank and rewrite the completed statement:
.................... is the largest gland in the body.
Which part of alimentary canal receives bile from the liver?
(a) oesophagus
(b) small intestine
(c) stomach
(d) large intestine
The first enzyme to mix with food in the digestive tract is:
(a) pepsin
(b) cellulose
(c) amylase
(d) trypsin
When a person eats sugary food, then organisms A present in his mouth act on sugar to produce a substance B. The substance B first dissolves the calcium salts from the top part C of the tooth and then from its middle part D forming holes E. These holes ultimately reach the part F in the lower part of tooth which contains nerves and blood vessels. The substance B irritates the nerve endings inside the tooth causing toothache.
(a) What are (i) organisms A, and (ii) substance B?
(b) What are (i) part C, and (ii) part D, of tooth known as?
(c) By what name are the holes E in the tooth known?
(d) Name the part F of the tooth.
(e) What will happen if organisms A reach part F of the tooth known?
The partially digested food coming from the stomach of a person enters a long and narrow organ A in his body. The organ A receives the secretion of two glands : liver and pancreas. Liver secretes a greenish-yellow liquid B which is normally stored in the organ C. Pancreas secretes pancreatic juice which contains three digestive enzymes D, E and F. The intestinal juice completes the process of digestion of food. The inner wall of organ A has millions of tiny finger-like projections G which help in the rapid absorption of digested food into blood stream. The undigested part of food then passes into wider tube H which absorbs most of the water from undigested food. The last part of tube H called I stores this undigested food (or waste) for some time. The undigested food is then passed out though opening J as faeces in the process known as K.
(a) Name the organ A.
(b) Name (i) liquid B, and (ii) organ C.
(c) What are the digestive enzymes D, E and F?
(d) Name the projections G present on the inner wall of organ A.
(e) Name (i) tube H (ii) part I (iii) opening J, and (iv) process K.
Write the function of the following in the human alimentary canal:
Villi
Define with examples: Autotrophs
Correct the spellings: HLC
The question has four options. Choose the correct answer:
The liver performs the function of
A few drops of iodine solution were added to rice water. The solution turned blue-black in colour. This indicates that rice water contains:
