1. Based on the video describe all the steps in digestion. Please be specific with all of the organs,
and what occurs with the different macronutrients (carbohydrates, fat, protein). Start with the
mouth and continue from there. Be specific – including enzymes if mentioned, organs, and what
occurs with the macronutrients. (6pts)
Required: This should be very detailed. Each organ should include at least one sentence in terms of
its functions.
Type the information in your own words.
Video here: (Khan Academy – Digesting Food)
Digesting Food (video) | Life processes | Khan Academy Links to an external site.
*if this doesn’t work, please google “Khan Academy Digesting Food”
2. RSVP - After reading Chapter 3, list one statement for each of the following (5pts)
R (reflection): Reflect on Ch 3 and describe something that stood out to you.
S (Summary): Summarize a concept in Ch 3.
V (Vocabulary): List at least one new word you learned and what it means.
P (Pose a question): What other questions do you have on the chapter?
3. Review the section in the book about GI issues and diseases. Choose two of these. Describe the
issue, symptoms, treatment, and any specific nutrition treatments for the issue. (4
The process of digestion involves the breakdown of food into smaller components that the
body can absorb and utilize.
1. Mouth

Digestion: Chewing breaks food into smaller pieces, increasing surface area for
enzymes to act.

o
o
Carbohydrates: Salivary glands release saliva, which contains the enzyme.
Some enzymes are formed under the carbohydrate which is called the Salivary
Amylase which works to start the digestion of carbohydrates in the body.
salivary glands This enzyme begins breaking down complex carbohydrates
into smaller molecules.

o
o
o
o
Fats: Salivary lipase, glands in the tongue which begins the breakdown of fat.
Proteins: No protein digestion occurs in the mouth.
2. Esophagus


Food passes down through the tube called the esophagus.
No significant digestion of macronutrients occurs here.
3. Stomach


Digestion: The stomach churns food, mixing it with gastric lipase. The liquid that
leaves the stomach is called chyme through PYLORICSPHINCTER.
Chemical Digestion:
o Proteins: Hydrochloric acid (HCl). The enzyme that breaks proteins into
smaller piece. Pepsin digest proteins.
o
o
o
o
Fats: Gastric lipase (means it comes from the stomach)
Carbohydrates: No carbohydrate digestion occurs in the stomach due to the
acidic environment in salivary amylase.
4. Small Intestine (Duodenum, Jejunum, Ileum)

The small intestine is the primary site for digestion and absorption of macronutrients.
The pancreas, liver, and gallbladder contribute to this process.
Duodenum (First Section of the Small Intestine)


The liver sort chemicals called BILE.
o The small intestine tube is about 15 to 30 feet.
o Bile: Produced by the liver and stored in the gallbladder, fats for easier
digestion by enzymes.
Carbohydrates:
o
o

Pancreas
Amylase
Fats:
o
o

Bile
Pancreatic Lipase: Digestion of fat.
Proteins:
o Chymotrypsin: Released as inactive enzymes and activated in the small
intestine.
o Trypsin
o
Jejunum and Ileum




Most nutrient absorption occurs here.
Carbohydrates: glucose, fructose are absorbed into the bloodstream via active
transport.
Proteins: acids are absorbed into the bloodstream through active transport
5. Large Intestine (Colon)


No significant digestion of macronutrients occurs here.
Functions:
o Absorbs water, electrolytes, and some vitamins.
o It ends in an X shape part called sigmoid colon. It more like a storage and
drying unit with ascending, transverse and descending.
6. Anus

Waste material (feces) is stored in the rectum and eliminated through the anus.
Each organ and enzyme play a vital role in ensuring macronutrients are broken down into their
simplest forms for absorption and use by the body.
Summary of Macronutrient Digestion:
1. Carbohydrates:
o Start in the mouth with salivary amylase.
o Completed in the small intestine by pancreatic amylase enzymes.
o
2. Fats:
o
o
o
Begin minimally in the mouth and stomach.
Major digestion in the small intestine via bile and pancreatic lipase.
Absorbed as fatty acids, reassembled into triglycerides, and transported via
lymph.
3. Proteins:
o Start in the stomach with pepsin.
o Completed in the small intestine with enzymes like trypsin and chymotrypsin.
4.
o
o
1. Reflection
One aspect that stood out in Chapter 3 of "Understanding Nutrition" The human body utilizes
a highly coordinated system to transform food into usable nutrients, which involves
mechanical and chemical breakdown, absorption through the intestinal walls, and transport of
these nutrients to cells. This complex highlights the essential roles of enzymes, hormones,
and the specialized structures of the gastrointestinal tract, as well as the impact that various
factors such as diet and health status can have on nutrient availability. The book also
highlights how different enzymes like Amylase, Lipase and Trypsin process to digest
Carbohydrates, Fats and Proteins.
2. Summary of the Concept
It explains the journey of food through the digestive system, starting from ingestion to
excretion.




Mouth: Food is chewed and mixed with saliva, where enzymes like amylase begin
breaking down carbohydrates.
Stomach: Food is churned and mixed with pepsin take action on protein digestion.
Small Intestine: The majority of digestion and nutrient absorption occurs here.
Large Intestine: Water and some minerals are absorbed.
The pancreas and liver also play vital roles by producing enzymes and bile that assist in this
breakdown. Once nutrients are absorbed through the small intestinal lining, they enter the
bloodstream for transportation to cells throughout the body.
3. New Words Learned
Here are some words encounter in the chapter:




Chyme: The semi-liquid mixture of partially digested food and digestive food formed
in the stomach.
Peristalsis: The muscle contractions that move food through the digestive tract.
Microvilli: Finger-like projections found on the surface area of the cell in the small
intestine that increase nutrient absorption.
Trypsin: The proteolytic enzyme that is found in the small intestine which breaks
down proteins.

Some thoughtful questions that could arise based on the reflection and summary of Chapter
3, "Digestion, Absorption, and Transport."
Complexity of the Digestive Process


What are the mechanisms that regulate the release of digestive enzymes and
hormones.
How do various enzymes function differently at their stages of digestion and what
role do they play in breaking down foods.