LAB - GI and Starch Digestion Flashcards
enzyme measurement is important to diagnose
heart attack and liver disfunction
enzymes are biological catalysts which are
proteins that speed up the rate of a reaction without permanently changing the enzymes themselves
amylase converts what and what into what
Starch and water into maltose
The shape of the enzyme provides a pocket called
Active site
The shape of the active site determines the
specificity of the enzyme
the active site has a 3d structure that allows the substrate to
temporarily attach
the substrate of a reaction is the
molecule that is acted on by the enzyme
The product is a result of the
enzyme catalysis
The equation always has enzymes on the top of the arrow, substrates to the left of the arrow and product to the right
amylase
starch + H2O _____maltose
enzymes are very specific about the reactions they
catalyze
each enzyme usually catalyses only a single reaction however,
they can catalyze that same reaction many times without wearing out.
Some enzymes catalyze a synthesis reaction which is
the conversion of two substrates into a larger product.
enzyme assays
are used to determine if an enzyme is working
amylase catalyzes the hydrolysis of starch to alogosacharides including matose
for this enzyme assay we are able to detect the presence of starch, the substate, and maltose, one of the products to determine enzyme activity.
after preparing the test tubes with reagents a sample goes on a dish then we add lugose iodine. when lugose iodine and starch come into contact you get a
blue black color which indicates a positive starch test
When starch is absent the addition of lugose iodine produces a light yellow color. This represent a
negative starch test
The absence of starch indicates a functional salivary amylase
because amylase breaks down starch.
Another way to test the activity of amylase is to test for the
presence of the products of the catalysists reducing sugars
Benedict’s reagents tests for the presence of
reducing sugars such as maltose, glucose and fuctose
A positive sugar test is detected as a color change from the original blue to
green, orange, or burnt orange
A negative sugar test is detected when the solution
remains blue after the benedict’s reagent and boiling step
typically a bell shaped curve illustrates how an enzyme performs at various temperatures most enzymes have an
optimal temperature at which they function best.
the peak of the curve indicates the optimal temp where enzymatic activity is the
highest
As the temperature of the enzyme change the structure of the
active site also changes and this new shape may or may not be able to accommodate the substrate
What is an enzyme?
A protein that acts as a biological catalyst to speed up a chemical reaction.
What is a catalyst?
Substance that increases the rate of a chemical reaction without itself becoming chemically changed or part of the product.
What is a substrate?
A reactant on which an enzyme acts to cause a chemical action to proceed
What is the product?
the result of the enzyme catalysis
Peptide are
two or more amino acids linked together by a peptide bond
a peptide chain containing 10-100 amino acids is typically called a
polypeptide
during digestion ______ cells of the stomach secrete a protein digesting enzyme called pepsin
chief cells
Pepsin is a
protein digesting enzyme
pepsin _________ peptide bonds
hydrolyzes
_______ is a synthetic peptide that releases a yellow dye product when hydrolyzed
BAPNA
negative results with negative controls validate the experiment. negative controls are used to determine whether there are any contaminating substances are present to cause the change.
True
When a positive result is produced but a negative result is expected, one or more contaminating substances are present to cause the change
True
Where in the body does protein digestion begin?
The stomach
The substrate for pepsin is
protein
there are four layers in the walls of the digestive tract
- deepest layer is the mucosal layer. 2. submucosa has blood vessels and nerves. 3. muscularis externa - circular muscle and longitudinal muscle which is smooth muscle 4. serosa
if you swallow a penny what layer would the layer be touching?
mucossa
if you swallow a penny and the dr has to operate what is the first layer she will cut?
serosa.
small intestine is the only place that has the
villi and microvilli and lacteals
in the small intestine we increase surface area by
plicae villi or circular folds, villa and microvilla
does the liver make any digestive enzymes?
NO
What are the main type of gland cells in the stomach?
parietal, chief and enterendocrine
what does the parietal cells secrete?
hydrochloric acid
what does the chief cell secrete?
pepsinogen which is the inactive form of pepsin
what do the enterendocrine cells secrete?
hormones like gastrin
the common bile duct and the pancreatic duct dump into the
duodenum of the small intestine
if you see a tube like thing in front of a pancreas and the question is what organ the answer is
small intestine. when it asks for more specificity the answer is duodenum.
Bile goes to the _____ to be concentrated and stored
gallbladder
the bile from the gallbladder goes from the common bile duct into the duodnum
True
lobes of the liver
left, right, quadrate, cuadate
lobules are the
small units of the liver
portal triad is made of 3 parts
a portion of the hepatic portal artery, a portion of the hepatic portal vein and a portion of the bile duct.
bile coniculai is where the
bile is moving from the center of the lobules to the outside ends
In the center of the lobules is the
central vein
in all the lobules the blood goes towards the central vein and then the central veins unite to make the
hepatic vein that comes out the liver
coming in and out of the gallbladder is the
cystic duct
from the liver are the left and right hepatic ducts
True
the right and left hepatic ducts form the
common hepatic ducts
The common hepatic duct along with the cystic duct forms the
common bile duct
fat pad
greater omenta
What are the 3 layers of muscles in the stomach?
oblique, circular, longitudinal
what is the role of the peyer’s patch?
lymphatic tissue that are a part of immunity.
ways to increase surface area in the stomach
rugae
ways to increase surface area in the small intestine
microvilli, villi and plica circularis (circular folds)
Put the large intestine in the correct order from the cecum on?
ascending colon, transverse colon, descending colon, sigmoidal colon, rectum, anus.
What’s the role of the cecum?
it’s just the connection between the small intestine and large intestine. A receiving area for the stuff that wasn’t absorbed by the small intestine.
What’s the role of the cecum?
it’s just the connection between the small intestine and large intestine. A receiving area for the stuff that wasn’t absorbed by the small intestine. Some people say it’s the dirtiest place in the human body.
How does surface area effect enzymatic reaction?
Increased surface area speeds up a reaction.
The typical temperature for most of our reaction is 37 degrees which is
body temp
What are the parts and the order of the large intestine or colon?
cecum, ascending colon, transverse colon, descending colon, sigmoidal colon, rectum and anus
know the internal and external sphincter
Internal anal sphincter is smooth muscle and involuntarily controled and the external sphincter is skeletol muscle and voluntarily controled
What’s the role of the cecum?
To receive the undigested food from the small intestine.
at 100 degrees you’d have so much kinetic energy but you see
no enzymatic reaction. Because the enzyme is denatured and non-functional
lesser and greater omentum are
specialized mesentary that come off the curvature in the stomach they cover the small intestine. these specialized mesentaries are there to store fat.
lacteals are there to help absorb
fats - lacteals, lipids, lymph
small intestine have the peyer’s patch and they are apart of
immunity because it’s apart of the lympatic and immune system.
The order of the parts of the small intestine
duodenum, jejunum, illium
The lesser omentum anchors the
liver to the lesser curvature of the stomach
The greater omentum drapes inferiorly from the
greater curvature of the stomach to cover the coils of the small intestine. It then runs dorsally and superiorly, wrapping the spleen and the transverse portion of the large intestine.
Triglycerides are the most abundant fats in the diet (p. 45). Where is the primary site of their digestion?
The small intestine is the primary site of lipid digestion
What organ produces lipase, a fat digesting enzyme?
the pancreas
lipase is produced in the _____ and released in the ________
pancreas, small intestine
What does lipase break down?
lipids or fats
Pancreatic amylase is produced in the _______ and secreted by the_______
pancrease, small intestine
Salivary amylase is produced in the _______ and secreted in the _______
salivary glands, mouth.
maltase is produced in the ______ and secreted in the ________
SI, SI
pepsin is produced in _______ and secreted by________
gastic glands in the stomach (chief cells), stomach
trypsin is produced in the _______ and secreted by________
pancrease, SI
peptidases is produced in the _______ and secreted by________
Small intestine, small intestine
nuclease is produced in the _______ and secreted by________
pancreas, small intestine
nucleosidases is produced in the _______ and secreted by________
pancreas, small intestine
Lipase is produced in the _______ and secreted by________
pancrease, small intestine
What are the enzymes that break down carbohydrates?
salivary amylase, pancreatic amylase and maltase
What are the enzymes that break down protein?
pepsin, trypsin, peptidases
What are the enzymes that break down fats or lipids
lipase
What four organic molecules are found in all living things?
carbohydrates, proteins, lipids and nucleic acid.
what are the mechanical and chemical digestion processes in the mouth?
chewing and swallowing are mechanical. Chemical digestion occurs of carbohydrates and fats
what are the mechanical and chemical digestion and absorptive processes in the stomach?
Mechanical - peristaltic mixing and propulsion. chemical digestion of proteins and fats. absorption - lipid soluble substances such as alcohol and aspirin.
what are the mechanical and chemical digestion and absorptive processes in the small intestine?
mechanical - mixing and propulsion primarily by segmentation. chemical - carbs, fats, polypeptides, nucleic acids. Absorption of peptides, amino acids, glucose, fructose, fats, water, minerals and vitamins (everything)
what are the mechanical and chemical digestion and absorptive processes in the large intestine?
mechanical - segmental mixing and propulsion. NO chemical digestion (except by bacteria). Absorption of ions, water, mineral and organic molecules
what is the enzyme, the substrate and the product for triglyerides?
enzyme - lipase. substrate - triglycerides. product - fatty acids.
what is the enzyme, the substrate and the product for protein?
enzyme - pepsin in the stomach and trypsin in the small intestine. substrate - protein. product - peptides.
what is the enzyme, the substrate and the product for peptides which are the product of protein digestion?
enzyme - peptidases. substrate - peptides. Product - amino acids.
What speeds up chemical digestion by breaking down our ingested nutrients into small molecules?
enzymes
what begins digestion?
chewing and swallowing
stomach turns triaclylglycerols into
dighlycerides and fatty acids
small intestine combines bile with
separated fats
proteins break down into
denatured and partially hydrolyzed protein in the stomach then small peptides, amino acids in the small intestine, then amino acids go into the blood stream in the large intestine.
starch digestion break down goes like this:
starch or glycogen breaks down into disaccharides (maltose, sucrose and lactose) in the mouth, then monosaccharides (glucose and fructose) in the small intestine
starch or glycogen is a
polysacharide
maltose is a
disaccharides
glucose is a
monosaccharides
maltase is made up of
2 glucose molecules bonded together
