Digestive Flashcards
Define carbohydrate
A molecule composed of sugar subunits that contain carbon, hydrogen, and oxygen in a 1:2:1 ratio
Define polymer
A molecule composed of three or more subunits
Define monosaccharide
A single sugar unit
Define isomer
One of a group of chemicals that have the same chemical formula but different arrangements
Define disaccharide
A sugar formed by the joining of two monosaccharide subunits
Define dehydration synthesis
The process by which larger molecules are formed by the removal of water from two smaller molecules
Define hydrolysis
The process by which larger molecules are split into smaller molecules by the addition of water
Define polysaccharide
A carbohydrate composed of many single sugar subunits
Define starch
A plant carbohydrate used to store energy
Define glycogen
The form of carbohydrate storage in animals
Define cellulose
A plant polysaccharide that makes up plant cell walls
Define triglyceride
A lipid composed of glycerol and three fatty acids
Define fat
A lipid composed of glycerol and saturated fatty acids, solid at room temperature
Define oil
A lipid composed of glycerol and unsaturated fatty acids, liquid at room temperature
Define phospholipid
A lipid with a phosphate molecule attached to the glycerol backbone, making the molecule polar. The main components of cell membrane
Define wax
A long chain lipid that is insoluble in water
Define protein
A chain of amino acids that form the structural parts of cells or act as antibodies or enzymes
Define amino acids
A chemical that contains nitrogen; can be linked together to form proteins
Define peptide bonds
The bond that joins amino acids
Define polypeptide
A chain of three or more amino acids
Define essential amino acids
An amino acid that must be obtained from the diet
Define denaturation
The process that occurs when the bonds of a protein molecule are disrupted causing a momentary change in shape
Define coagulation
The process that occurs when the bonds of a protein molecule are disrupted, causing a permanent change in shape
Define catalyst
A chemical that increases the rate of chemical reactions without altering the products or being altered itself
Define enzyme
A protein catalyst that permits chemical reactions to proceed at low temperatures
Define substrate
A molecule on which an enzyme works
Define active site
The area of an enzyme that combines with the substance
Define cofactor
An inorganic ion that helps and enzyme combine with a substrate molecule
Define competitive inhibitor
A molecule with a shape complimentary to a specific enzymes that competes with the substrate to access the active site of the enzyme and blocks chemical reactions
Define feedback inhibition
The inhibition of an enzyme in a metabolic pathway by the final product of that pathway
Define precursor activity
The activation of the last enzyme in a metabolic pathway by the initial substrate
Define allosteric activity
A change in an enzyme caused by the binding of a molecule
Define amylase
An enzyme that breaks down complex carbohydrates such as starch
Define peristalsis
Rhythmic, wavelike contractions of muscle that move food along the gastrointestinal tract
Define sphincter
A constrictor muscle that regulates the opening and closing of a tubelike structure
Define mucus
A protective lubricating substance composed mainly of protein
Define pepsin
A protein digesting enzyme produced in the stomach
Define ulcer
A lesion on the surface of an organ
Define duodenum
The first segment of the small intestine
Define villi
Small fingerlike projections that extend into the small intestine to increase surface area for absorption
Define microvilli
Microscopic, fingerlike projections of the cell membrane
Define capillary
A blood vessel that connects arteries and veins; the site of fluid and gas exchange
Define lacteal
A small vessel that transports the products of fat digestion to the circulatory system
Define secretin
A hormone released from the duodenum that stimulates pancreatic and bile secretions
Define enterokinase
An enzyme of the small intestine that converts trypsinogen trypsin
Define trypsin
A protein digesting enzyme
Define erepsin
An enzyme that completes protein digestion by converting short chain peptides to amino acids
Define lipase
A lipid digesting enzyme
Define bile salts
A component of bile that breaks down large fat globules
Define cholecystokinin
A hormone secreted by the small intestine that stimulates the release of bile salts
Define detoxify
To remove the effects of a poison
Define gallstone
Crystals of bile salts that form in the gallbladder
Define jaundice
The yellowish discolouration of the skin and other tissues brought about by the collection of bile pigments in the blood
Define cirrhosis
Chronic inflammation of the liver tissue characterized by the growth of non functioning fibrous tissue
Define colon
The largest segment of the large intestine, where water reabsorption occurs
Define gastrin
A hormone secreted by the stomach that stimulates the release of hydrochloric acid
Define enterogastrone
A hormone secreted by the small intestine that decreases gastric secretions motility
What are the five chemicals of life?
Vitamins and minerals Lipids Nuclei acids Proteins Carbohydrates
Carbohydrates are molecules that contain ____________, ____________, and ___________.
Hydrogen
Oxygen
Carbon
What is the preferred source of energy for cells?
Carbohydrates
Lipids are compounds formed from____________ and ________________
Glycerol
Fatty acids
Lipids are ________________ compounds
Energy storing
Proteins are molecules constructed of ________________. Proteins are the ___________ components of cells.
Amino acids
Structural
What does saliva contain and what is its function?
Saliva contains amylase enzymes that break down carbohydrates and activates taste buds and lubricates food
What is the function of the mouth
Chewing and digestion of starch
What is the function of the stomach
Storage of food and initial digestion’s of proteins
What is the function of the small intestine
Digestion of carbohydrates, proteins, lipids; the absorption of nutrients
What is the function of the pancreas
Production of digestive enzymes that act on food in the small intestine; storage of bicarbonate ions that neutralize stomach aid in the small intestine
What is the function of the large intestine
Absorption of water and storage of undigested food
What do the salivary glads secrete and what is their function
Salivary amylase
Initiates the breakdown of polysaccharides to simpler carbohydrates
What does the stomach secrete and what is its function in digestion
Hydrochloric acid, pepsinogen, mucus
HCl converts pepsinogen to pepsin. Pepsinogen kills microbes when converted to pepsin, initiates the digestion of proteins. Mucus protects the stomach from pepsin and HCl
What does the pancreas secrete and what is its function in digestion
Pancreatic amylase, bicarbonate ions, trypsinogen, lipase
Pancreatic amylase continues the breakdown of carbohydrates into disaccharides. Bicarbonate ions neutralize HCl from the stomach. Trypsinogen when activated to trypsin, converts long chain peptides into short chain peptides. Lipase breaks down fats to glycerol and fatty acids
What does the small intestine secrete and what is its purpose in digestion
Erepsin, disaccharidases
Erepsin completes the breakdown of proteins, dissaccharidases break down disaccharides into monosaccharides
What does the liver secrete and what is its function in digestion
Bile
Biles emulsifies fat
What does the gallbladder secrete and what is it function
Bile
Bile stores and secretes concentrated bile from the liver
What does the large intestine secrete and what is its function
Mucus
Mucus helps movement of food waste
