Chapter 10……..Digestion

Student Should be able to:

·        Relate the importance of the digestive system

·        Compare a physical change and a chemical change in the digestive system

·        Explain the role of enzymes in a chemical change

·        Trace the path of food from the mouth to the body cells

·        Identify the accessory glands and their role in digestion

·        Name the organs ,glands, juices, and enzymes involved in the complete digestion of carbohydrates, lipids and proteins

·        Compare the human digestive system with those of other animals

·        Identify the problems of the digestive system

Chapter Outline

1.     Digestion of food into usable form 

2.     Food passes from the mouth , esophagus, stomach, small intestine, large intestine, rectum, finally through the anus

3.     Physical change is breaking of food into smaller pieces while Chemical change is into simpler form

4.  Enzymes:

·        are biocatalysts that increase the rate of reactions without being used

·        are specific each enzyme act on a specific substrate ( Key-lock theory)

·        work max. at 40 C , denaturated above 40 C, and inactivated by lower Temp.

·        act in a specific medium acidic (stomach), neutral ( mouth), or basic ( small intestine)

5.     Table of digestion                                 

6.     Digestion of carbohydrate starts in the mouth, proteins starts in the stomach, lipids starts in the small intestine and all digestion ends in the small intestine

7.     Absorption through villi

8.     Digestive system problems: heart burn and  ulcer

9.     digestion  in other animals

Enzymes: salivary and pancreatic  amylase, pepsin, rennin, trypsin, lipase, erepsin, nuclease, maltase, lactase, sucrase

Digestion process and diagram  ; Study Guide 55-60