DIGESTIVE SYSTEM (CONTINUED) ENOTE

WEEK TWO

SUBJECT: BASIC SCIENCE

CLASS: GRADE 8

TERM: SECOND

TOPIC: DIGESTIVE SYSTEM (CONTINUED)

PROBLEMS ASSOCIATED WITH DIGESTIVE SYSTEM:

Common digestive problems include the following

·        Constipation: Constipation involves having fewer than three bowel movements a week. Stools may be firm or hard to passed, your abdomen may feel swollen or bloated.

·        Diarrhea: Diarrhea is having three or more loose bowel movements a day. It can also cause cramping.

·        Acid reflux: Acid reflux happens when the muscle in your oesophagus that opens and closes when you swallow does not work properly. When this happens, food and digestive fluids, which contain acid, back up into your esophagus. Acid reflux can cause a burning feeling in your chest and throat, which is sometimes called heartburn.

·        Hemorrhoids: Hemorrhoids are swollen blood vessels in and around the anus and lower rectum. The vessels stretch under pressure. They can become painful, itchy and irritated. Passing stool may injure the hemorrhoids and cause them to bleed.

SIMPLE FOOD TEST:

Food	Test	Observation	Inference
Carbohydrate: Glucose	(a)Add Fehlings Solutions A and B and boil	A red precipitate	Glucose is present
	(b)Add Benedicts Solution (5ml) to 10 drops of sample	A yellow precipitate	Glucose is present
Sucrose	Repeat Benedict test and if negative add one or two drops of HCl and boil	A yellow precipitate	Sucrose is present
Starch	Crush yam and make solution of it. Add iodine solution	A blue-black color	Starch is present
Cellulose	Add concentrated H2SO4 to cotton wool. Add few drops of iodine	A blue color	Cellulose is present
Protein	(a)Add Millions reagent to egg albumen and heat	A white precipitate which quickly turns brick red	Protein is present
	(b)To 3ml of milk add 1ml of NaOH plus 1 drop of 1% CuSO4 (Buiret Test)	A purple colour appears	Protein is present
	(c)Add Conc. Trioxonitrate (V) acid HNO3 to egg white. Should be handled with care. Heat, cool and add  ammonia (Xanthoproteic test)	An Orange precipitate appears	Protein is present
	(d)Add equal Conc HNO3 to either egg or milk	Dense, white  curds are formed	Protein is present
Fats	(a)Make a smear of test substance on a white paper	Paper becomes translucent	Fat is present
	(b)To 1ml of milk, add few drops of Sudan III	A red color appears	Fat is present
	(c)To test substance add a few drops of osmic acid	A brownish black coloration appears	Fat is present

ASSIGNMENT

OBJECTIVE QUESTIONS:

1. The main reason for taking large amount of water with food is to A. aid digestion of food B. aid food intake C. flush the alimentary canal D. increase appetite   

2. Iodine was added to a food substance, it changed to blue black. This shows that the food substance contains A. amino acid B. fats C. oil D. starch

3. Gastric juice is found in the A. bile B. liver C. mouth D. stomach

4. Which of these is NOT a part of human digestive system? A. Diaphragm B. Gullet C. ileum D. mouth

5. The type of food that aids digestion is A. carbohydrate B. fat C. mineral salt D. protein E. vitamins

6. The end product of protein is A. glucose B. amino acid C. fatty acid D. glycerol

THEORY QUESTIONS:
1. List four problems associated with digestive system.

2. What is constipation?

3. What is diarrhea?