Digestive System Flashcards
(69 cards)
What are the three main categories of compounds obtained from food?
- Carbohydrates
- Lipids
- Proteins
Each category plays a distinct role in the body and is broken down differently.
What is the main role of carbohydrates in the body?
Main source of energy for the body
Humans cannot synthesize carbohydrates and must obtain them from food.
What is the general structure of carbohydrates?
Contain at least 1 carbon atom, 2 hydrogen atoms, and 1 oxygen atom, typically in a 1:2:1 ratio
Example: Glucose (C6H12O6) follows this ratio.
Define monosaccharides.
A single sugar unit
Examples include glucose, fructose, and galactose.
Define disaccharides.
Two sugar units
Formed by linking two monosaccharides.
Define polysaccharides.
More than two sugar units
Examples include starch and cellulose.
What test is used for simple sugars like glucose?
Benedict’s Test
Positive result shows a color change from blue to various colors based on sugar concentration.
What test is used for complex sugars like starch?
Iodine test
Positive result shows a color change from yellow-brown to dark blue-black.
What defines a reducing sugar?
A sugar that can give away its electrons during chemical reactions
Monosaccharides are considered reducing sugars.
What is dehydration synthesis?
The process of linking monosaccharides to form disaccharides, involving loss of hydroxide and hydrogen ions
Water (H2O) is released as a by-product.
What are triglycerides?
Formed by the union of glycerol and 3 fatty acids
They act as stored energy for cells.
Differentiate between saturated and unsaturated fatty acids.
Saturated: only single bonds, solid at room temperature
Unsaturated: at least one double bond, liquid at room temperature
Saturated fats are often referred to as ‘bad’ fats.
What is hydrogenation?
The process of converting unsaturated fats to saturated fats by adding hydrogen
This is done for culinary purposes to improve texture and shelf life.
What is trans fat?
Chemically altered unsaturated fatty acid high in LDL cholesterol
Linked to heart disease and banned in many places.
What role do phospholipids play in the cell membrane?
Form the phospholipid bilayer due to their amphipathic nature
They possess both hydrophilic and hydrophobic ends.
What is the main role of proteins?
Repair damage to cells, speed up chemical reactions, and help defend against disease
Proteins are not a primary source of energy.
What test is used for proteins?
Biuret Test
Positive result shows a color change from blue to purple/lilac.
What factors influence enzyme activity?
- Temperature
- pH
- Substrate concentration
Each factor can increase or decrease enzyme efficiency.
What are the two main divisions of the digestive system?
- Accessory Organs
- Digestive Tract/Alimentary Canal
Accessory organs aid digestion without handling food.
What is the function of the esophageal sphincter?
Prevents stomach acid from splashing back into the esophagus
Helps prevent heartburn.
What role does the liver play in digestion?
Secretes bile salts that aid in fat digestion
Bile emulsifies lipids for easier digestion.
What enzymes does the pancreas secrete into the small intestine?
- Trypsin
- Chymotrypsin
- Pancreatic amylase
- Lipase
These enzymes help digest proteins, starches, and lipids.
What is the primary function of the small intestine?
Complete digestion of macromolecules and absorb nutrients
Surface area is increased by villi and microvilli.
What is the role of the appendix in digestion?
Hypothesized to store ‘good’ bacteria for digestion
It can become inflamed if it absorbs harmful bacteria.
