Biology 12- Digestive System I,II,III

Terms in this set (106)

List the 4 major hydrolysis reactions
Polysaccharide, Proteins, Lipids, and Nuclei acid
What is the enzyme for Polysaccharide?
Salivary Amylase/Pancreatic Amylase
What is the Polysaccharide Intermediate?
Maltose
What is the Polysaccharide Enzyme 2?
Maltase
What is the monomer for Polysaccharide?
Glucose
What is the enzyme for Protein?
Pepsin/Trypsin
What is the Protein Intermediate?
Polypeptides
What is the Protein Enzyme 2?
Peptidase
What is the monomer for Proteins?
Amino Acids
What is the enzyme for Nuclei Acids?
Nuclease
What does nuclease do?
Breaks nucleic acids into nucleotides
What is the monomer for Nuclei acids?
Nucleotides
What is the enzyme for Lipids?
Bile
What is bile?
An emulsifier
What does an emulsifier do?
Breaks down larger globules into smaller globules
What is the lipid Intermediate?
Fat droplets
What is the lipid Enzyme 2?
Lipase
What is the monomer for Lipids?
Glycerol and Fatty Acids
What is the PH of the mouth/oral cavity?
Neutral 6.2-7
What do savilary glands realease and what does it do?
Amylase- breaks starch into maltose
What adds lubrication to food?
Mucous and water
What does the tongue do in order to swallow?
Contracts
Which gland is attached to the oral cavity?
Salivary gland
What does the salivary gland do?
Secretes saliva containing water, mucous, savilary amylase by way of ducts
What is the pharynx?
Common passage for air and food at the back of the throat
What does the pharynx do?
Transfers food from mouth to esophagus
What is the epiglottis?
Flap of tissue above trachea
What does the epiglottis do?
Covers trachea for swallowing so food does not enter air way
What is the Esophagus?
Muscular tube between pharynx and stomach
What does the esophagus do?
Transfers food from pharynx to stomach through peristalsis
What is the cardiac sphincter?
Circle of muscle at the top of stomach
What does it do?
Controls entrance of food to and from the stomach
What is the PH of the Stomach?
Acidic 1.5-2.2
What do the walls of the stomach do?
Churn and mix food
What is secreted in the stomach?
Mucous and acid
What does the mucous do?
Protects the stomach
What do acid (HCL) conditions do?
Convert pepsinogen to pepsin to activate the enzyme
What chemical digestion happens in the stomach?
Protein to polypeptides by pepsin
What is the pyloric sphincter?
Circle of muscle at bottom of stomach
What does the pyloric sphincter do?
Controls the exit of the stomach
What is food called at the P sphincter?
Chyme
What state is food in at the P sphincter?
Liquid
What is the duodenum?
First part of the the small intestine/biggest part of the digestive system
What does the duodenum do?
Completes digestion of all four biological molecules and final breakdown of molecules digested by mouth and stomach
What do the duodenum walls secrete?
Peptidase and maltase
What hormones does the duodenum secrete?
CCK and secretin which act on the pancreas and gall bladder to release juices
What is the liver?
Dark brown accessory organ on right of body below right lung and above intestines
List 6 major functions of the liver.
Destroys old red blood cells
Makes bile
Manufactures blood proteins
Regulates blood glucose levels
Removes poisonous substances from the blood
Break down of proteins
How does insulin regulate glucose levels?
By turning glucose into glycogen after a meal
What is present to convert glycogen back into glucose?
Glucagon
How does the liver remove poisonous substances?
It metabolizes them
What is the gall bladder?
Small green sac in folds of liver
What does the gall bladder do?
Stores bile until it is secreted into the duodenum
What is the pancreas?
Long flat organ below stomach and attached to duodenum by the pancreatic duct
What does the pancreas do?
Produces digestive enzymes for the first step of chemical digestion
Produces sodium bicarbonate to buffer acid from stomach
What makes up the small intestine?
Duodenum, jejunum and ileum
What is the major structure of the small intestine?
The villus
What is a villus?
The lining of the small intestine
What does the villus contain?
Blood supply and lacteal of lymphatic system
What makes the small intestine good for absorbtion?
Highly vascular- lots of blood vessles to absorb nutrients into blood
What is the major site for chemical digestion?
Duodenum
List the process of the water soluble nutrients in the small intestine:
Villus- capillaries-hepatic portal vein-liver capillaries
What happens to fatty soluble monomers?
Enter the lacteal and are carried away by the lymphatic system
What is the appendix
Small sac at juncture of small and large intestines
What is the large intestine also known as?
Colon
What is the large intestine?
Wider and shorter tube between small intestine and rectum
What does the large intestine do?
Absorbs water and water soluble minerals and vitamins
What does the large intestine do with E.Coli?
Manufactures vitamins
What happens if the LI absorbs water too fast?
Stomach ache
What is the rectum?
Short tube between large intestine and anal sphincter
What does the rectum do?
Holding area for feces
What is the anus?
Circle of muscle at the end of the digestive tract
What does the anus do?
Controls the exit of feces
What is food called once it begins breaking down?
Bolus
What are the 4 steps of swallowing?
Reflex action, epiglottis covers the opening to the trachea, contraction of the tongue and pharynx, bolus is pushed to esophagus
Where does peristalisis take place?
Stomach, intestines, esophagus
When is insulin secreted?
When blood glucose is high such as after a meal
What does insulin do?
Lowers blood glucose level to normal
What is the insulin source gland?
Pancreas
What does insulin stimulate liver to do?
Store glucose as glycogen
What other stimulations does insulin have?
Liver, muscle and fat to take up and metabolize glucose
What does glucagon do?
Turns glycogen into glucose
Where is bile produced?
Liver
What happens when you combine bile and fat droplets?
Becomes polar
When bile/fat droplets become polar, what is enabled?
Lipase is able to digest it
What are two specialized folds in the small intestine?
Villi and microvilli
What do villi and microvilli do?
Increases available surface area for absorbtion
What does the glandular tissue of the small intestine do?
Secretes enzymes for chemical digestion
What does the muscle in the small intestine do?
Churns food
What do goblet cells do in the small intestine?
Secrete mucous to protect the lining of the intestine
What do the capillaries around the lacteal do?
Absorb nutrients by transporting them away from the digestive tract
What do lacteals do?
Collect and absorb lipids
What does salivary juice include?
Water for hydrolysis, mucous to lubricate, salivary amylase to convert starch into maltose
What is gastric juice sometimes referred to as?
Chyme
Where is gastric juice found?
Stomach
What does gastrin do?
Causes the release of pepsinogen/pepsin
What does HCl do?
Brings pH below 3 to activate the enzyme converting pepsinogen to pepsin and kills microbes
What does mucous do in the stomach?
Protects the walls with lipid layer
What does mucous in the stomach protect from?
Pepsin digesting the stomach
Where is pancreatic juice found?
In the duodenum
What does sodium bicarbonate in pancreatic juice do?
Brings up the pH of the chyme from the stomach
What does pancreatic amylase do?
Catalyses starch to maltose
Where does trypsin convert proteins to polypeptides?
Small intestine
Where does lipase convert lipids to glycerol?
small intestine
Where does nuclease convert nucleic acids to nucleotides?
Small intestine
List the 7 juices and secretions found in the duodenum:
CCK
Secretin
Pancreatic juice
gastric juice
Maltase
Peptidase
Bile from liver
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