GI absorptions Flashcards
(21 cards)
difference between facilited, passive (simple) and primary active transport
facillitated= need a protein to help
simple= don’t require transport protein. made easier with fatty substances and small.
primary active transport= uses energy and one transport protein
differnece between primary and secondary active transport
primary= carrier protein uses energy directly from ATP
secondary= uses energy stored in concentration gradients of ions
what type of movement would each of the following have across the membrane
1) oxygen
2) sodium
3) glucose
4) fatty acid
1) simple diffusion (non polar and small)
2) facilitated diffusion
3) faciliatated diffusion
4) simple diffusion
function of sodium/ potassium ATP-ase pump as key to intestinal absorbtion
-large amount of sodium ouside cells compared to insdie to create a sodium gradient
what can be absorbed?
carbohydrates> monosaccharides
-size of chain for starches and sugars
sucrose and lactose enzymes used to break down sugars and what is absorbed
starches- long chain
sugar- shorter chain
sucrose breaks down glucose to fructose via GLUT 5
lactose breaks glucose to galatose via SGLT1
how carbs are digested in
1) mouth
2) pancreas
3) small intenstine microvilli
1) salivary amylase (breaks down starch to maltose)
2) pancreatic amylase (breaks down starch maltose)
3) specific oligosaccardes produces monosaccharides
1)what does fructose use to be transported by facililited diffusion?
2)what does glucose and galactose use to be transported by secondary active transport
1) GLUT5
2) SGLT1
which monosaccharides require energy for absorbtion (active transport) and can be transported against electrochemical gradent
glucose and galactose
(fructose cannot becasue it’s absorbed by facilitiated diffusion)
other than food what are other ways we absorb protein
from digestive juices and dead mucosal cells
where are the enzymes used to break protein in small molecules and what do they do
-pepsin
-tyrsin
-chymotrypsin
-carboxypeptidase
-brush border peptidase
stomach- pepsin (produce smaller polypeptide chains)
small intestine microvilli- peptidase (Produce tripeptides, dipeptides and amino acid)
pancreas- rest of them (produce small peptide chains)
what are amino acid transporters?
why is there transport similar to carbs?
-each amino acid class has a different cohort of transporters
-break down into small molecules and absorb across cells
Which enzyme is largely responsible for the breakdown of lipids in adults? What component parts does this enzyme break triglycerides into
pancreas lipase breaks tryglycerides into monoglycerides and free fatty acids
how is fat absorbed
-bile
-michelle
-chylomicrons
-exocytosis
-enter lacteals
1) fat broken down by bile
2) forms michelles then free fatty acid and monosaccharrides leave michelles and diffuse into epithelial cells
3) the brocken lipids are put back together into triglycerides again to form chylomicrons
4) they are noe big again to exluded from epithelial cells by exocytosis.
5) carried into intestine by lymph
why do chylomicrons enter lymph rather than blood
too large to enter blood
lymphatic capillaries lack a basement membrane and more permeable to large partciles
what are vitamins
organic substances that cannot be made by body but absorbed in small intestine
how are fat soluble and water soluble vitamins carried and absorbed
-where and how is vitamin K and B absorbed
fat= carried by micelles and diffuse into absorbative cells
water= absorbed by passive or active transport
vit K and B= in large intestine from bacterial metabolism
how could a blockage of bile duct lead to vitain E deficiency
vitamin e is fat soluble therefore carried via micelles
how are electrolytes transported
1) iron
2) calcium
3) sodium
4) pottasium
active transport
3) coupled with absorbtion of glucose and amino acids. faciliated transport
4) diffuses in response to osmotic gradients
How do the plicae circulares, villi, and microvilli contribute to the function of the small intestine?
-they increase the surface area for absorbtion and digestion
-nutrients are absorbed into the bloodstream by passve or active transport
-lipids are absorbed into lymph by lacteals in villi by michelle by faciliated transport
what three areas of GI tract are fats brocken down by and what enzyme are used
mouth (lipase
stomach (gastrin lipase)
pancreaic (pancreatic lipase)
what transport mechanims does amino acid use to be absorbed in small intestine
secondary active transport coupled to sodium
