Digestion & Absorption Flashcards
What is the Alimentary Canal?
Structures form a ‘tube’ called the alimentary canal.
What are the major structures of the digestive system?
Mouth, Esophagus, stomach, gall bladder, small intestine, large intestine, pancreas, liver
What is the mouth, and what does it do?
chewing mechanical
digests food, which increases
surface area
What is the esophagus and what does it do?
transports food
to stomach via peristalsis
What is the stomach and what does it do?
churns food and
has acidic environment that
kills pathogens and activates
enzymes.
What is the small intestine and what does it do?
has
enzymes that chemically
digest biomolecules. Wall
absorbs small molecules.
What does the liver do?
secretes bile
What does the Gall bladder do?
stores and
regulates bile
What does the pancreas do?
secretes lipase,
amylase and protease
What does the large intestine do?
absorbs
water and compacts waste to
form feces
What is Peristalsis?
a wave of muscle
contractions that pushes food
through the gut and mixes it with
enzymes.
What happens in the intestinal wall?
enzymes break macromolecules into monomers that can be absorbed by the intestinal wall. This is done via hydrolysis.
What does protease / peptidase do?
digest proteins into amino acids
What does Amylase do?
digests starches
& glycogens into simple
sugars
What does Nuclease do?
digests nucleic
acids into nucleotides
What does Lipase do?
digests lipids into
fatty acids
Which polymer remains undigested?
Cellulose
What is Absorption?
the process of taking substances into cells and mainly occurs in the small intestine. The rate of absorption depends on the surface area available.
What are villi?
finger-like projections of the mucosa that the inner
intestine wall.
What is Starch?
a macromolecule that is made in plants by joining
α-glucose molecules.
Where is Glucose transported to?
Glucose is transported from the lumen to the capillaries
How are Fatty Acids transported?
- Triglycerides are broken down into fatty acids, which diffuse into cells
- Inside, they combine with cholesterol and proteins to form lipoproteins
- The lipoproteins are excreted via exocytosis
- They then enter the lacteal and are carried away from the intestines
