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Digestive Exam Review
1.
What is digestion?
Digestion involves the mixing of food. It involves movement through the digestive tract,
and chemical break down of the large molecules of food into smaller molecules the body
can use.
2.
Summarize the process of digestion.
Food enters the mouth where both mechanical and chemical digestion takes place. Food
travels through esophagus by the process of peristalsis, which pushes it to the stomach.
This is where chemical and mechanical digestion continues. Food then enters the small
intestine as molecules that enter into the blood stream so it can be distributed
throughout the body. What is left-over enters into the large intestines where excess
water is removed and feces are formed. From there, it is held in the rectum until it
exits through the anus.
3.
Describe mechanical digestion. Where does it occur? Does it produce physical or
chemical change?
Mechanical digestion is the process where food is broken down by chewing, mixing, and
churning. It occurs in the mouth and stomach, and produces a physical change.
4.
Describe chemical digestion. Where does it occur? Does it produce physical or chemical
change?
Chemical digestion is the process that occurs when chemicals break down large food
molecules into smaller ones that can be absorbed by the body. It occurs in the mouth,
stomach, and small intestines. Saliva, acids, and enzymes produce a chemical change.
5.
What is the function of the digestive system? Why is it so important and what system
works with it once the process is complete?
It breaks down food into usable substances. Without this system food would not be able
to fuel our body.
6.
How does the digestive system break down large molecules into smaller ones?
The digestive system breaks down large molecules by using saliva, HCl (hydrochloric acid)
and enzymes to chemically break bonds.
7.
Simon ate a cracker. As soon as he put it in his mouth, it started to dissolve. What
caused the cracker to dissolve?
Saliva began to break down the carbohydrates in the crackers.
8.
Define chyme and where is it created?
Thin, water product of digestion that moves slowly out of the stomach and into the small
intestine
9.
Create a Venn diagram showing the differences between physical and chemical changes.
Physical
Chemical
●Breaks into smaller
pieces
●Use of chemical
properties
●no new substances
formed
Ex: cutting carrots,
biting, chewing food
● Change in
appearance
● Both
occur
in digestion
●new substances
formed
Ex: rusting, food
digested in small
intestine
10. Give an example of physical changes and chemical changes that occur within the
digestive system.
Physical: Biting, chewing, churning
Chemical: Carbs broken down into sugars for energy