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what goes Gs stimulate
stimulates adenlyl cyclase
what does Gq stimulates
stimulates inositol triphosphate and diaclyglycerol
what does Gi inhibits
what is Gt associated with?
associated with transducin (generates a signal in the retinal rods upon exposure to light)
____ toxin actives adenylyl cyclase in intestinal mucosa, resulting in a loss of salts from the intestinal epithelium
- (this is an exotoxin)
- It eventually causes osmotic diarrhea
____ toxin inhibits the inhibition of adenylyl cyclase (so activates it)
pertusis (whooping cough)
pertussis does what?
inhibits the inhibition of adenylyl cyclase
cholera does what?
activates adenylyl cyclase
cyclic AMP gets broken down to 5'-AMP by what enzyme?
cyclic nucleotide phosphodiesterase
what is the pharmacological protein in inhibition of different PDEs (2)
methlyxanthine derivatives (theophylline and caffeine)
sildenafil (viagra)--inhibits a PDE and increases blood flow to the penis
True/False: every human live cell in the body glycolysis occurs
All cells have anaerobic—occurs in cytoplasm
Many cells will continue in the mitochondria with aerobic process that is way more efficient
GLUTs involvement in basal glucose uptake from blood and other extracellular fluids (found in most tissues) (3)
which GLUT is found in liver and kidney cells
what does affinity in a GLUT mean?
strength of binding
what does capacity of a GLUT mean?
how many receptor molecules are there to interact with glucose
What is the affinity and capacity of GLUT 2 (liver and kidney cells)
why do the GLUT 2 in the liver and kidney have high capacity but low affinity?
If the liver had high affinity—it would store all of it as glycogen and no be able to give it to the rest of the body so it must have LOW affinity
High capacity—liver is big and at some point you might need to store it after a big meal and can take in a lot of glucose
Affinity for the GLUTs in average cell are very _____
Most of the GLUTS with basal glucose metabolism is ____ affinity
high—want the glucose to get into the cell to feed itself
GLUT 2 also functions as a glucose sensor in _____ ____ ____
pancreatic beta cells
lets the pancreas know that there is a glucose present so the beta cells can make insulin
GLUT 5 does what?
insulin sensitive GLUT is _____ which is found in adipose tissue and skeletal muscle tissue
How does insulin work on GLUTS
Insulin recruits inactive glucose transporters (GLUTs) in the Golgi and translocates them to the plasma membrane
Once insulin has been released from the pancreas it really activates the actions of GLUT 4
Glut 4 works better in the presence or absence of insulin
what is oral rehydration therapy
in order to treat dehydration (due to disease or diarrhea), water with added amounts of Na and glucose are administered ORALLY to patients
**doesnt address underlying issue but helps with dehydration
2.5 million kids die from diarrheal dehydration!!!!!
What are added amounts of Na and glucose added to water in oral rehydration therapy?
Na and glucose will go through SGLT and will get into the blood and will help keep the water inside
what is a 5 carbon sugar called and what is an example
what is a 6 carbon sugar called and what is an example
what is a 9 carbon sugar called and what is an example
True/False: glucose is primarily in the L form like amino acids
FALSE IT IS THE D FORM
in glucose which carbon is 1 and which is 4?
the carbon below the O that is in the ring is 1
the carbon that is below the carbon with another one attached (hanging off the ring) is the 4
Glucose and fructose have the same chemical formula but the only difference is
glucose is an aldose and fructose is a ketose
glucose is a reducing sugar. Tests for reducing sugars include:
- Benedict's reagent
- Fehling's soution
- Tollen's reagent
Clinitest tables are based on the same principles as benedict's reagent
the presence of reducing sugars in the urine might be indicative of metabolic disorders of ____ or _____ metabolism as well as _____
what are fructose and galactose reducing sugars
Monosaccharaides are reducing my definition because they are not linked to anything—the reducing end is free
glucose at concentration ____ is the major reducing chemical in blood
A commonly utilized enzymatic assay for blood glucose today uses glucose oxidase and peroxidase.
The hydrogen peroxide produced will oxidize a (colorless) ______ to a (color-bearing) ______
what hydrolyzes sucrose (glucose+ fructose--in that ORDER)
what hydrolyses lactose
is lactose a reducing disaccharide?
maltose is a product of the hydrolysis of _____
maltose is hydrolyzed by _____
is maltose a reducing disaccaride?
what is the difference between maltose and isomaltose
Maltose (glucose+ glucose)
Isomaltose (glucose + glucose in alpha 1,6 linkage)
Isomaltose is a product of ___ and ____ partial hydrolysis
is isomaltose a reducing disaccaride
true /false starch can be broken down by both isomaltoses and maltose
starch is composed of what two things (in what %) and what is the difference
Amylose (25%)-- a straight chain polysaccharide composed of D-glucose monomers
Amylopectin (75%)--a branched chain polysaccharide composed of D-glucose monomers joined by both alpha 1,4 bonds and also alpha 1,6 bonds (branch points)
True/False: Cellulose is the most abundant of all carbohydrates on this planet, serving as a structural component in plants
what is the molecule formed from glucose and glucose linked by a beta 1,4 glycosidic bond
Do we have the enzyme to digest a beta 1,4 glycosidic bond between 2 glucose molecules
non-cho parts that carbs can be attached to by glycosidic bonds
what enzymes hydrolyze glycosidic bonds
** a hydrolytic enzyme--adds water
alpha amylase cuts dietary starch and glycogen where?
at the internal alpha 1,4 bonds at random intervals
what is an example of a endoglucosidase and what does that mean
it means it cuts in the middle (not at one end)
The final digestion of carbohydrates occurs primarily at the mucosal lining of the upper jejunum by disaccharidases of the intestinal brush-border membrane
The disaccharidases include the following (5):
- Lactase (beta galactosidase)
what is the other name for lactase
the disaccharaidases are associated with what side of the intestinal brush border membrane
if you eat food containing lactose, starch, sucrose and cellulose which sugar(s) get digested in the mouth
the only one that is digested is starch and you get:
- starch dextrins
Isomaltase is made up of what
two glucose (alpha 1,6)
lactose is made up of what?
glucose and galactose
sucrose is made up of what
glucose and fructose--IN THAT ORDER
maltose is made up of what
glucose and glucose
Galactose and glucose are transported into the mucosal cells by ______
SGLT-1 (sodium-dependent glucose cotransporter)
Fructose is transported by _____ which does not require sodium
Glucose, galactose, and fructose are all transported into the portal circulation by ____
SGLT for the most part are found in _____ (SGLT 2) and ____ ____ (____) (SGLT 1)
intestinal cells (enterocytes)
True/False: the mutation related to lactose intolerances occurs in the lactose gene
The mutation does NOT occur in the lactase gene at all—occurs in an intron of a neighboring gene
word for lactose intolerance
A relative sweetness scale assigning sucrose the value of ____
what is another salivary endoglycosidase that breaks the glycosidic bonds in bacterial cell walls?
sugars that done promote caries (8)
Fiber (cellulose, pectin, gums, beta-glucans)
Polymonosaccharides (sorbitol, mannitol, xylitol, erythritol)
Polyolmonosaccharides (lactitol, isomalt,maltitol)
Salivary amylase hydrolyzes
the alpha 1,4 glycosidic bond
The bonds in cellulose are
beta 1,4 glycosidic bonds
The bonds that are in amylopectin are
alpha 1,4 and alpha 1,6 glycosidic bonds
The bonds that are in glycogen are
alpha 1,4 and alpha 1,6 glycosidic bonds
Sucrase hydrolyzes the
alpha 1,2 glycosidic bond
Lactase hydrolyzes the
beta 1,4 glycosidic bond