Digestion and Absorption (C) Flashcards
What is hydrolysis?
The breakdown of a molecule by adding water
What is a catalyst enzyme?
One that causes another reaction but is not a part of it
What is a bolus?
A mouthful of food ready to be swallowed
How long is the esophagus?
10 inches
Which body part prevents gastric reflux?
Lower esophageal sphincter/ Cardiac sphincter
How is food moved down the esophagus?
Peristalsis and gravity
What are the sections of the stomach?
Upper (fundus,) body, end (pylorus)
Which enzyme triggers the release of gastric juices as chyme enters the pylorus?
Gastrin
What is gastric juice made up of?
Hydrochloric acid, pepsin, and mucus
What is the function of hydrochloric acid?
Activates pepsin and prepares molecules for partial digestion by it, destroys most bacteria, and makes iron and calcium more soluble.
What is the function of mucus in the stomach?
Protect it from hydrochloric acid
Which enzymes are found only in childrens’ stomachs? What do they digest?
Rennin and gastric lipase, for milk protein and milkfat respectively
What are the sections of the small intestine?
Duodenum, jejunum, ileum
Which enzyme triggers the release of sodium bicarbonate when chyme enters the small intestine?
Secretin
What is the function of sodium bicarbonate in the small intestine?
Neutralize acidity of the chyme
Which enzyme triggers the release of bile when fat enters the small intestine?
Cholecystokinin (CKK)
Where is bile created? Where is it stored?
Created in liver, stored in gallbladder
What is the purpose of bile?
Emulsify fat in order to be digested by enzymes
What are the three pancreatic enzymes present in the small intestine?
Proteases (trypsin, chymotrypsin, and carboxypeptidases,) which split proteins; amylase, which breaks down starch; lipase
What enzymes does the small intestine itself secrete?
Lactase, maltase, and sucrase; peptidases, which turns proteins to amino acids
What are the sections of the large intestine?
Cecum, colon, rectum
What is the appendix?
A diverticulum extending off of the cecum
What are the volatile fatty acids used for energy from the large intestine?
Acetate, propionate, and butyrate
How long is the small intestine
20 feet
What do capillaries in the villi/microvilli absorb?
Simple sugars, amino acids, minerals, and water-soluble vitamins
What do lacteals in the villi/microvilli absorb?
Glycerol, fatty acids, and fat-soluble vitamins
Which organ converts fructose and galactose to glucose?
The liver
How long is the large intestine?
5 feet. 3 inches diameter
What are the tasks of the large intestine?
Absorb water, synthesize vitamin K and B-complex, and collect food residue
What is body waste made up of?
Fiber, connective tissue in meat, bacteria, fats bonded to minerals, mucus, and water.
What percent of carbs are absorbed?
99%
What percent of fats are absorbed?
95%
What percent of proteins are absorbed?
92%
How long does it usually take from ingestion to excretion?
16-27 hours
What is the difference between aerobic and anaerobic metabolism?
Oxidation occurs in aerobic metabolism. Aerobic metabolism reduces carbs and proteins, while anaerobic reduces fats
What is the Krebs Cycle?
The complete oxidation cycle
Which hormones does the thyroid secrete?
Triiodothronine (T3) and thyroxine (T4)
What are the symptoms of hypothyroidism?
Sluggishness and weight gain
How many KJs = 1kcal?
4.184
How many calories are in a gram of alcohol?
7 calories
Which enzymes are present in the stomach?
Pepsin (acts on protein); rennin and gastric lipase in children
