DLA 1+2+3+4 and Lecture 1+2 Flashcards
what are the two regulated steps of glycolysis?
what do those enzymes do?
ATP used?
- glucokinase / hexokinase
convert glucose to glucose 6-phosphate - PFK-1
irreversible reaction of fructose 6-phosphate to fructose 1,6- bisphosphate
2 ATP are used
Aldolase A and B
location? function?
aldolase A is in muscle; aldolase B is found in the liver
aldolase B is needed for fructose metabolism
these two enzymes convert fructose 1,6-biphosphate to either G3P or Dihydroxyacetone phosphate
what enzyme in glycolysis results in NADH
Glyceraldehyde 3-phosphate dehydrogenase
what enzymes in glycolysis results in ATP formation?
Phosphoglycerate kinase pyruvate kinase (irreversible reaction)
function of LDH?
convert between pyruvate and lactate
can go either way
the higher the NADH levels the more (blank) produced?
lactate
what is a reducing sugar?
sugar that has a free aldehyde or keto group
Review of GLUT 1, 2, 3, and 4?
GLUT 1 = neurons and RBC
GLUT 2 = liver
GLUT 3 = neurons
GLUT 4 = adipose tissue and muscle (insulin-responsive)
glucokinase vs hexokinase?
glucokinase:
In the liver and pancreatic B cells
have a high Km and high Vmax
more active when blood sugar is high
hexokinase:
most other tissues
low Km
The key enzyme in the PPP and main products?
enzyme: G6PD
forms NADPH
forms ribose phosphate
requires vitamin B1 or TPP for the enzyme transketolase
The fates of pyruvate
either the TCA cycle if oxygen is present
cori cycle if no oxygen is present
Fate of the cori cycle?
converts lactate from the skeletal muscles and RBC’s to glucose (in the liver)
The actions of arsenic?
inhibits the enzyme glyceraldehyde 3-phosphate dehydrogenase
inhibits mitochondrial enzymes, as well
presentation of lactic acidosis?
high anion gap metabolic acidosis
low pH
decreased HCO3
decreased CO2
elevated lactate levels
the 3 irreversible reactions in glycolysis?
glucokinase
PFK-1
pyruvate kinase
Role of Fructose 2,6 biphosphate
high blood levels: insulin active dephosphorylated active PFK-2 increases fructose 2,6 biphosphate allosterically activates PFK-1 for glycolysis
low blood levels: glucagon active phosphorylated FBP-2 active decreases fructose 2,6 biphosphate activates fructose 1,6 biphosphatase for gluconeogenesis
blood supply of the foregut?
blood supply of midgut?
also hindgut?
foregut: celiac
midgut: superior mesenteric
hindgut: inferior mesenteric
The development of the stomach?
distal part of the foregut shows a fusiform dilation which has right and left surfaces and anterior and posterior borders
as the size of the stomach grows the posterior border or greater curvature grows faster than the anterior border or lesser curvature
the stomach does rotate 90 degrees
dorsal and ventral mesogastrium?
dorsal: greater omentum, gastrosplenic ligament, and splenorenal ligament
ventral: falciform ligament and lesser omentum
congenital hypertrophic pyloric stenosis
narrowing of the lumen of the pyloric canal due to hypertrophy of the muscles
stomach of baby will be distended and will lead to projectile vomiting
vomitus is not bile stained
will be seen between 3 weeks to 5 months after birth
can be seen by barium swallow or ultrasound
development of the duodenum
develops from the caudal part of the foregut and the cranial part of the midgut
as the stomach rotates the duodenum takes on a C-shape and rotates to the right.
Duodenal stenosis
partial occlusion of the lumen due to incomplete recanalization
leads to vomiting which is bile stained
duodenal atresia
complete occlusion of the lumen due to failure to recanalize
will see polyhydramnios
vomiting will begin right after birth
will see double bubble sign!
development of the liver and biliary apparatus
The hepatic diverticulum arises during the 4th week of development from the caudal part of the foregut
this will extend into the septum transversum
hepatic diverticulum has cranial and caudal parts
cranial part forms the liver
caudal part forms the gallbladder and cystic duct
major papilla
dividing point between the foregut and midgut
hepatopancreatic ampulla - common opening for bile duct and pancreatic duct
development of the pancreas?
the pancreas develops from two endodermal buds from the distal end of the foregut
the ventral and dorsal buds fuse by the 7th week
annular pancreas
due to bifid ventral pancreatic bud
can wrap around the duodenum and cause an obstruction
development of the spleen
the spleen is derived from mesenchymal cells between the layers of dorsal mesogastrium
