The inability to digest lactose.
Lock and key hypothesis
attempts to explain the mechanism of enzyme specificity. This hypothesis has largely been replaced by the idea of an "induced fit".
The region of an enzyme that attaches to a substrate.
Chemical and mechanical breakdown of food.
Organs of the human digestive system (In order)
Oral cavity, pharynx, espohagus, stomach, small intestine, large intestine
Involuntary muscular contractions that move chewed and moistened food through the esophagus.
A wound that results when the wall of the stomach fails to protect itself from digestion.
The surface projections of the epithelial cells lining the intestine, which increase the area for absorption.
An enzyme that is present in children but less abundanet or absent in adults
This nutrient does not begin undergoing digestion until it reaches the small intestine.
Carbohydrates are broken into these when they are digested.
Nucleic acids are broken into these when they are digested.
Proteins are broken into these when they are digested.
The starch-digesting enzyme secreted by the salivary glands.
Breaks up fat globules into smaller droplets (emulsification).
An enzyme produced by the pancreas that helps to further digest proteins in the small intestine.
Region where absorption of food mostly takes place.
Region where the physical breakdown of food begins
Region where protein digestion begins
Region where pancreatic juice and bile neutralize acids
Absorption of water is one of its major functions.
Bile from the liver is stored here.
A bolus moves through the espohagus by means of these muscular contractions.
A flap of cartilage that flips down to cover the entry to the trachea during swallowing.
Reflux (of acid chyme from the stomach into the lower esophagus)
This is usually the cause of heartburn.
Cardiac sphincter (a constriction at the base of the esophagus)
Usually prevents the movement of food from the stomach into the esophagus.
Retains acid chyme in the stomach until pepsin digestion is complete.
Mix of food and stomach secretions.
An organic catalyst that speeds up a chemical reaction by lowering its activation energy without being used up in the reaction.
An organic catalyst. Usually made of protein.
Energy necessary to start a reaction.
The molecule that an enzyme acts on.
Enzymes are usually named by adding this ending to the name of the substrate.
A substance chemically similar to the substrate that "fools" the enzyme by binding to the active site.
A series of ridges that line the surface of the stomach, increasing its surface area.
A process in which proteins lose their structure (and thus their function) through exposure to extreme stress (high heat, pH, etc.).