What is the role of saliva in the digestion of food?
Human digestive system includes various glands and salivary gland is one of them. Saliva is secreted by salivary gland located under the tongue which helps in the digestion of food and it contains water, salts, mucin and some enzymes salivary amylase or ptyalin. PH is neutral i.e, 6.7. about 1.5 litres saliva and mucus are secreted in every 24 hours in the buccal cavity. Salivation activation depends on the smell, idea and imagination of food.
Role of saliva:
- Saliva moistens food and this changes it into the semisolid mass for easily swallowing and moisten of food allows stimulation of taste buds.
- Salvia moistens and burnish (lubrication) the buccal mucosa, tongue and lips which makes speech or fluent speaking possible.
- Its pH is neutral 6.7 and acidity is very low, so this prevents tooth decay.
- It contains many salivary enzymes which kills many bacteria that are present in the buccal cavity with the food.
Popular Questions of Class 10 Science
- Q:-
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.*Are structural isomers possible for bromopentane?
- Q:-
Outline a project which aims to find the dominant coat colour in dogs.
- Q:-
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common? - Q:-
Calculate the number of electrons constituting one coulomb of charge.
- Q:-
How is the sex of the child determined in human beings?
- Q:-
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
- Q:-
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
- Q:-
What is an homologous series? Explain with an example.
- Q:-
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
- Q:-
Why is variation beneficial to the species but not necessarily for the individual?
Recently Viewed Questions of Class 10 Science
- Q:-
Why do you think the noble gases are placed in a separate group?
- Q:-
Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.
- Q:-
Which of the following constitute a food-chain?
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat - Q:-
How does chemical coordination take place in animals?
- Q:-
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
- Q:-
Write the balanced equation for the following chemical reactions.
1. Hydrogen + Chlorine → Hydrogen chloride
2. Barium chloride + Aluminium sulphate → Barium sulphate + Aluminium chloride
3. Sodium + Water → Sodium hydroxide + Hydrogen - Q:-
List five things you have done over the last one week to —
(a) conserve our natural resources.
(b) increase the pressure on our natural resources. - Q:-
Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas?
- Q:-
A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes. On this basis, can we say anything about whether the light eye colour trait is dominant or recessive? Why or why not?
- Q:-
Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.
- NCERT Chapter