Exercise digestive system.pdf

Science Module Form 2 - Chapter 2

Digestion

The process of breaking down large food molecules into smaller molecules that can be readily absorbed by the body.

It consists of : Mouth Oesophagus Stomach Small intestine Large intestine Anus Tips : Mak - Mouth Oteh - Oesophagus Suka - Stomach Duduk - Duodenum Sama Intan - Small Intestine Laili Ibni - Large Intestine Anus - Anus

Mout h s

Stomac h

Duodenum

Lower part of small intestine Appendix Starch

The end products of digestion

Protein

Fat 1

Science Module Form 2 - Chapter 2

Organs

Secretions

(a) Mouth

Enzymes

Saliva

Actions Salivary amylase

(a) _____________

Starch

(b) Oesophagus

(c) Stomach

-

-

(i) Gastric juice

Maltose

(c) ___________________ (Contraction and relaxation of wall in the alimentary canal)

(d) _____________

Pepsin

Protein

(d) Duodenum

peptones

(ii) Hydrochloric acid

-

-

Kills bacteria in food. Provides an acidic medium suitable for the action of protease.

(i) Bile

-

-

Emulsifies the fats into oil droplets. Pancreatic amylase

(ii) Pancreatic juice

(i) ____________

Starch

Maltose Pepsin

(ii) ____________

Protein

Peptones Lipase

(iii) ___________

(e) Small Intestine

Fat

Fatty Acids& Glycerol Maltase

(i) Intestinal juice (i) ____________

Maltose

Glucose Pepsin

(ii) ____________

Polypeptides

Amino Acid

Lipase

(iii) ____________

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Fat

Fatty Acids& Glycerol

Science Module Form 2 - Chapter 2

Beri-beri Night Blindness Fibre Fatty acids & glycerol

Amino acid Rickets Scurvy

Carbohydrate Minerals Sterility

Fat Glucose Protein Water Prolonged bleeding

7 classes of food Vitamin A

Vitamin B

Vitamin C

Vitamin D

Vitamin Deficiency disease

Vitamin E

Vitamin K

Classes of food Carbohydrate Protein Fat

Vitamin and mineral Fibre Water

-

Function Supply the body with energy For growth and repair of body tissues provide energy heat insulator protect internal organs Dissolve vitamin AS, D, E and K. For healthy growth and development Prevent constipation Regulate body temperature Remove excretory products from body Transporting food

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Science Module Form 2 - Chapter 2

Food Tests

Food

Test

Observation

Word Express

Starch

Iodine test

turns Dark Blue

Glucose

Benedict’s test

turns Orange Precipitate

Gear B O P

Proteins

Millon’s test

turns Brick-red Precipitate

Pam Minyak BP

Fat

Emulsion test Filter paper

turns Milky-white emulsion Translucent Spot on filter paper

F EMoW

Age

State of health

Siti Ingat Dia Bagus

Size

Factors affect balanced diet

Climate

Sex

Job

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Science Module Form 2 - Chapter 2

Exercise 2.1

Classes of food

1. Diagram shows some examples of food.

The food shown is rich in a certain class of food. (a) Name the class of food. ___________________________________________________________ (b) Explain the digestion process that takes place on these food when they reach the stomach. ___________________________________________________________ ___________________________________________________________ (c) Name the end-product of digestion of these food. ___________________________________________________________ (d) State one function of this class of food. ___________________________________________________________

2. Diagrams below show three food tests. (a) Test for starch

(i) What is solution X? ______________________ (ii) What is the expected observation? ______________________ ______________________

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Science Module Form 2 - Chapter 2

(b) Test for sugar

(i) Identify solution Y? ______________________ (ii) What is the observation? ______________________ ______________________

(c ) Test for proteins

(i) Name the solution Z? ______________________ (ii) State the observation for this experiment. ______________________ ______________________

3. Diagram shows some examples of food.

(a) Name the three elements that are contained in these food. __________________________________________________________ 6

Science Module Form 2 - Chapter 2

(b) Name the class of these food. ___________________________________________________________ (c) State one function of this class of food. ___________________________________________________________ (d) Give two vitamins that dissolve in this class of food ___________________________________________________________ (e) Explain briefly how you can test for the presence of this class of food.. ___________________________________________________________ ___________________________________________________________

4. Complete of the description of the various food tests below :

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Science Module Form 2 - Chapter 2

5. Categories the food below into the correct food classes Rice Potato Butter

Bread Milk Egg yolk

Meat Egg white Honey Beans Vegetables Fish oil

Fish Coconut oils Fruit

Classes of food

Carbohydrates

Protein

Fats

Fibre

6. Diagram 1 shows several foods.

Diagram 1 (a) State the food class for each of the food shown in Diagram 1. (i) P : ______________________ (iii) R : ______________________ (v) T : ______________________

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(ii) Q : ____________________ (iv) S : ____________________ (vi) U : ____________________

Science Module Form 2 - Chapter 2

(b) Complete Table 1 Food P Q

Food test Millon’s test

T

Observation A transparent spot is formed on the filter paper. The food became blue black in colour

7. State the vitamin of the following vitamins deficiency diseases. Deficiency disease Scurvy Blood difficult to clot Rickets Night-blindness Infertility Beri-beri

Vitamins

8. (a) A student was given few food samples by his teacher. How can he test the presence of carbohydrates in the food sample? ________________________________________________________ (b) State the end product of digestion of carbohydrates in the small intestine. _______________________________________________________________

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Science Module Form 2 - Chapter 2

Exercise 2.2

The Importance of a Balanced Diet

Diagram 1 shows the classification of nutritious food in a Food Pyramid.

Diagram 1 (a) State the importance of using a food pyramid. ___________________________________________________________ (b) (i) What is the function of food class X? _________________________________________________________ (ii) What happen if an individual lacks class food X in his daily diet? ________________________________________________________ (c) Diagram 2 shows a person suffering from a kind of disease.

Diagram 2 (i) Which class of food will cause the disease in Diagram 2 if taken excessively in our daily diet? ________________________________________________________

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Science Module Form 2 - Chapter 2

Human Digestive System

Exercise 2.3

1. Diagram 1 shows the human digestive system.

Diagram 1 (a) On Diagram 1, label the following organs. Liver

Stomach

(b) State one function of organ R. ___________________________________________________________ (c) Name one type of simple food present in organ S. ___________________________________________________________ (d) What will happen to the simple food while it is inside organ S? ___________________________________________________________ (e) A food test is carried out on a food sample taken from organ S. Complete the observation of the test and the food class of the sample in the table below. Food test

Observation

A few drops of Benedict’s solution is added into the food sample. The mixture is then heated.

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Food class

Science Module Form 2 - Chapter 2

2. The diagram below shows a human digestive system.

(a) Name the organ labeled Q, R and U. (b) Which is the largest organ in the diagram. ___________________________________________________________ (c) Mark the organ where villus are found with ‘X’.

(d) Which organ in the diagram above produces bile? ___________________________________________________________

3. The diagram shows the human digestive

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Science Module Form 2 - Chapter 2

(a) Name the labeled parts of the human digestive system. P Q R S

: __________________ : __________________ : __________________ : __________________

T U V X

: ____________________ : ____________________ : ____________________ : ____________________

(b) State the type of enzyme, food digested and the end products in the organ T. Name of enzyme Type of food digested End product

: ____________________________________ : ____________________________________ : ____________________________________

(c) The liver secretes bile into the duodenum. What are the functions of bile? ___________________________________________________________ (d) Name parts of the human digestive system where starch is digested? ___________________________________________________________ (e) How does food moved through the alimentary canal? ___________________________________________________________

4. Diagram 2 shows part of the human digestive system.

Diagram 2 (a) Name the part labeled P and Q. P Q

: ____________________________________________________ : ____________________________________________________

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Science Module Form 2 - Chapter 2

(b) What is the function of Q? ___________________________________________________________ (c) What is the function of Villi on the inner surface of P? ___________________________________________________________ (d) Name two types of food which can be absorbed through the Villi. (i) ________________________________________________________ (ii) ________________________________________________________

5. Diagram 3 shows a human digestive system.

Diagram 3 (a) Label three of the following structures in Diagram 3.

Stomach

Small intestine

Liver

Large intestine

Pancreas

(b) State one function of organ T. ___________________________________________________________

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Science Module Form 2 - Chapter 2

(c) A student carried out a food test on sample M. Table 1 shows the results of the test. Complete Table 1 by writing the observation obtain from the food test. Food test Sample M is crushed and added with Millon’s reagent.

Observation

Food class

Sample M is added with a few drops of iodine solution.

6. Classify the following substances Glucose Glycerol

Proteins Fatty Acids

Amino acids Starch

Foods that can be absorbed into the small intestine

Fats Fibers

Foods that cannot be absorbed into the small intestine

7. Diagram 4 shows the human digestive system.

P

Diagram 4 15

Science Module Form 2 - Chapter 2

(a) (i) Label one of the following structure in Diagram 4.    

Pancreas Oesophagus Large intestine Liver

(ii) State one function of the structure labeled in 2 (a) (i). _________________________________________________________ (b) A sample of food, X consists mainly of fat. (i) Explain what happens to the food sample X in structure P. ________________________________________________________ ________________________________________________________ (ii) What is the final products of food X. ________________________________________________________ (c) Suggest one example of food that may possibly be the food sample X. ___________________________________________________________

8. State the enzymes and the final products of digestion for the following food.

Enzyme

Food

Protein

Fat

Starch

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Final Product

Science Module Form 2 - Chapter 2

9. Label the parts of the human digestive system shown below : Tips : Mak (Mouth) Oteh (Oesophagus) Suka (Stomach) Duduk (Duodenum) Sama Intan (Small Intestine) Laili Ibni (Large Intestine) Anus (Anus)

a) Based on the diagram above, state where the following processes occur in the human body. (i) Digestion of protein begin : __________________________________ (ii) Digestion completed : ____________________________________ (iii) Absorption of digested food :_________________________________ (iv) Bile produced here : ____________________________________ (v) Bile stored here : ____________________________________ b) How does food move from the mouth to the stomach? ___________________________________________________________ c) Diagram 5 shows an organ in our digestive system.

Diagram 5 (i) Name the organ : ________________________________________

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Science Module Form 2 - Chapter 2

(ii) The organ secretes gastric juices. Name the class of food that is digested by the gastric juices. ________________________________________________________ (iii) Name the acid in the gastric juices. ________________________________________________________ (iv) State three functions of the acid. ________________________________________________________ ________________________________________________________ ________________________________________________________

10. The diagram shows part of the human digestive system.

(a) In the diagram : (i) Mark the part that stores bile, as P. (ii) Mark the part that absorbs digested food, as R. (iii) Mark the part that receive digested food from blood vessel, as Q. (b) Name the organ in the diagram that digest protein earlier. ___________________________________________________________ (c) Name any two enzymes produced by R. ___________________________________________________________

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Science Module Form 2 - Chapter 2

11. Diagram shows an experiment to study the action of an enzyme in saliva on starch.

(a) Write a possible value of X. ___________________________________________________________ (b) The mixture in boiling tubes A and B is tested for the presence of starch and sugar after 10 minutes. Boiling tube

Test for Starch

Sugar

A B (c) What is the conclusion of the experiment? ___________________________________________________________ ___________________________________________________________ (d) Name the end-product of digestion of (i) Proteins (ii) Fats

: _______________________________________________ : _______________________________________________

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Science Module Form 2 - Chapter 2

12. Diagram 6 shows an experiment.

Diagram 6 (a) State the aim of this experiment. ___________________________________________________________ (b) State one hypothesis for this experiment. ___________________________________________________________ (c) What are represented by the distilled water and the Visking tube respectively?

(i) Distilled water (ii) Visking tube

: __________________________________________ : __________________________________________

(d) State the variables involved in this experiment. (i) Manipulated variable (ii) Responding variable

: ____________________________________ : ____________________________________

(e) Put a tick ( ) if the content is present and a cross (x) if the content is absent. Content of Visking tube At the beginning of the experiment After 15 minutes

Glucose

Starch

(f) State two other substances that can diffuse through the small intestine. ___________________________________________________________

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Science Module Form 2 - Chapter 2

13. Diagram 7 shows the apparatus set-up used to study the reaction of salivary amylase on starch. The solution in the test tube is tested for the presence of starch and simple sugar at the end of the experiment.

Diagram 7 (a) Predict the results of the experiment by completing Table 1.

Test tube P Q

Beginning of the experiment Starch Simple sugar Present Not present Present Not present

End of the experiment Starch Simple sugar

(b) What is in the saliva that enables starch to be digested? ___________________________________________________________ (c) What is the reaction of salivary enzyme that occurs in starch? ___________________________________________________________

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Science Module Form 2 - Chapter 2

14. The diagram shows the set-up of an experiment to study the absorption of food through the walls of the small intestine.

(a) What is represented by the (i) Visking tube (ii) water

: __________________________________________ : __________________________________________

(b) What should the temperature of the water in this experiment be? ___________________________________________________________ (c) The table shows the results of the food test carried on the water in the beaker at the beginning and at the end of the experiment. Food test Iodine solution Benedict’s solution

Beginning of the experiment No change in colour No change in colour

End of the experiment No change in colour A brick –red precipitate is formed

(d) What is detected in the water? ___________________________________________________________ (e) Name the enzyme in the saliva which acts on the starch. ___________________________________________________________ (f) Name the structure found in the inner wall of the small intestine which helps in the absorption of digested food. ___________________________________________________________

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