GI2 Flashcards by Jonathan Biederman

What are the functions of carbohydrates?

Energy source
Storage of energy
Cell membrane component
Structural

How well did you know this?

Not at all

Perfectly

Digestion of carbohydrates requires ___________ from the pancreas

Amylase

How well did you know this?

Not at all

Perfectly

What are the two phases of biotransformation?

Phase 1: oxidation adds a OH group (hydroxylation) or a COOH groups (carboxylation) in smooth ER and mitochondria

Phase 2: conjugation with glucuonic acid, glycine, or taurine

How well did you know this?

Not at all

Perfectly

What tubulo alveolar glands are located in the small intestine ?

Brunner gland

How well did you know this?

Not at all

Perfectly

________ pathway uses a glucose molecule to form 2pyruvate, 2NADH, and 2 ATP

Glycolysis

How well did you know this?

Not at all

Perfectly

What are the digestive enzymes produced in the pancreas?

Peptidases
Nucleases
Amylases
Lipase

How well did you know this?

Not at all

Perfectly

The pentose phosphate pathway produces what two important molecules

NADPH

Ribose-5-phosphate

How well did you know this?

Not at all

Perfectly

What stimulates the secretion of bile acids?

Increase amino acids and fatty acids in duodenum -> CCK release -> contraction of smooth muscle of the ducts and relaxation of Oddi’s sphincter

Reflectory -> ACh -> contraction of smooth muscle

How well did you know this?

Not at all

Perfectly

What are the 4 cell types of the small intestine and what do they secrete ?

Mature enterocytes
Goblet cells- mucus
Paneth cells - antimicrobial enzymes and peptides
Enteroendocrine cells- CCK, secretin, and. GIP

How well did you know this?

Not at all

Perfectly

A low pH in the intestine stimulates the release of _____________ hormone to stimulate _____________ rich pancreatic secretions

Secretin; bicarbonate

How well did you know this?

Not at all

Perfectly

The ____________ produces bile and it is stored and concentrated in the _____________

Hepatocytes of liver; and gallbladder

How well did you know this?

Not at all

Perfectly

What are the important biochemical events that allow the production of energy in the cell?

Pyruvate converted to Acetyl-CoA
TCA
Respiratory (electron transport) chain 
ATP synthesis by oxidative phosphorylation 
B-oxidation

How well did you know this?

Not at all

Perfectly

When food is hyperosmotic what is the direction of water movement?

Alll water secretion mediated by osmosis

Hyperosmotic draws water from the lateral spaces into intestinal lumen

How well did you know this?

Not at all

Perfectly

Where are nutrients absorbed from the intestine directed?

Hepatic portal vein passes through the liver

Lymphatic drainage enters blood stream through thoracic duct

How well did you know this?

Not at all

Perfectly

What condition, common in dogs, has pancreatic acini destroyed and replaced by CT

Pancreatitis

How well did you know this?

Not at all

Perfectly

What condition has insufficient production of digestive enzymes by exocrine pancreas?

Pancreatic insufficiency

How well did you know this?

Not at all

Perfectly

What are the important substrates for gluconeogenesis

Glycerol -> glycerol phosphate

Lactate -> pyruvate

Amino acids -> TCA -> oxaloacetate

Pancreatic cells have receptors for ?

ACh, CCK, and secretin

Pancreatic secretions adjust to food composition. Food with high starch stimulates ____________ enzyme production. High fat and protein foods stimulates increase __________ and __________ production

Amylase

Lipase and petidase

In aerobic glycolysis, pyruvate enters the _______ cycle within the mitochondria

Krebs cycle

What are the three levels of surface infoldings in the small intestines?

Plicae circulares
Villi
Microvilli

What hormones are synthesized in the liver?

Angiotensin gen -> prohomrone
Thrombopoetin -> hormone (growth factor)
IGF -> IGF 1 and 2
Hepcidin ->small peptide hormone

In anaerobic glycolysis, pyruvate is converted to _____

Lactate

What is the production of glucose from non-sugar molecules and where does this process occur?

Gluconeogenesis

Liver and kidney

What is the enterohepatic circulation of bile acids?

Bile acids secreted into the duodenum and reabsorbed in the ileum, transported back to the liver, to be used again (95%) Only 5% of bile acids are synthesized de novo in the liver

What immune system components are present in the small intestine?

M fold cells phagocytose bacteria Antigen presentation in peyers patches and mesenteric lymph nodes. Production of IgA antibodies that are secreted in the mucus

____________ cells of the small intestine arise from stem cells and differentiate into the cells of the small intestine

Progenitor

What is biotransformation?

Conversion of toxic molecules into non-toxic, water soluble and excretable substances (Increase polarity of drugs)

Brunners glands secrete what? And what is function of these secretions?

Glycoproteins and bicarbonate ion. Protection of small intestine mucosa by neutralizing the acid-containing chyme delivered to it from the stomach

What are the functions of the liver?

Metabolism of carbohydrates, amino acids, proteins, and lipids Storage of glycogen, lipid, vitamins, copper, and iron Synthesis of bile, hormones, and immune system components Biotransformation of medications, xenobiotics, and byproduct metabolism

Glycolysis is regulated by?

Phosphorylation /dephosphorylation of rate-limiting enzymes (short term) Hormonal influences on the proteins/enzymes synthesized (long term)

What is bile synthesized from and what important property does bile have?

Cholesterol conjugated to amino acids Amphipathic

Carbohydrates are absorbed apically by _____ and _______transporters, -pp32wppqand basolaterally by _____ transporters

SGLT and GLUT5- apically (Na dependent) | GLUT 2- basolaterally

An ______________ pathway uses energy to combine small molecules to form more complex molecules

Anabolic

What enzymes synthesized by the intestinal mucosa are required for digestion of carbohydrates?

Lactase Isomaltase Maltase Saccharase

An __________ pathway degrades energy rich molecules to capture energy

Catabolic

The pancreas produces _________ which must be activated to __________

Zymogens; proteases

What mechanism is used to store glucose in skeletal muscle and the liver?

Glycogenesis -> glucose to glycogen (glucose linked by 2-glycosidic bonds)

What are the gland like structures at the base of the villi in the small intestine?

Crypts of Leiberkuhn

What proteins are synthesized in the liver?

``` Albumins Lipoproteins Glycoproteins Prothrombin and fibrinogen Nonimmune a- and b- globulins ```

What is the function of NADPH ?

Electron source - > reductase - >electron transport chain - > cytochrome P450 (reduce) - >respiratory burst -> NO synthesis

Pancreatic juice contains what molecules? And what transporters are involved?

HCO3-, Na+, and K+ Paracellular - Na and K Cl- apical channel Na/K/Cl cotransporter (basolateral)