which non-glucose monosaccharides has the fastest rate of metabolism in the glycolytic pathway?(galactose, mannose, fructose)
☆fructose
fructose is the only one whose metabolites ☆bypass phosphofructokinase, one of the key enzymes involved in regulating the rate of glycolysis. As a result, fructose is metabolized by the liver faster than the other monosaccharides and is rapidly cleared from the bloodstream following dietary absorption. biochemistryUWorld HirotoShishido
which steps of collagen synthesis is impaired in the patient with Ehlers-Danlos syndrome, photoagingphotoaging→ increased degradation of collagen and elastin, ☆decreased collagen fibril production
specific symptom for cystic fibrosis(CF), cause of deathalmost all full-term infants with meconium ileus( by inspissated=dehydrated meconium)are eventually diagnosed with CF
mycophenolate
mechanism/ indicationimmunosuppressant
inhibition of inosine 5-monophosphate dehydrogenase(IMPDH)
(an enzyme in de novo purine synthesis pathyway)
relative lymphocyte specificity
(compared to other hematopoietic cell lines like neutrophils, erythrocyte)
what allows cells to progress through the G1→S checkpointactivation of cyclin D,E and corresponding cyclin kinases (CDK4 and 6(inhibitor=palbociclib→ breast cancer))→
☆retinoblastoma protein is hyperphosphorylated(inactive)→
↑intake of ketogenic nutrients(eg ☆lysine, leucine, high fat content)
・lactate dehydrogenase deficiency
Glycolysis is inhibited in strenuously exercising muscle as muscle cells ☆cannot regenerate NAD+
Consequently, high-intensity physical activity leads to muscle breakdown, pain, and fatigue as insufficient amounts of energy are being produced in the exercising muscle. biochemistryUWorld HirotoShishido
phenylketouria
findingsHypopigmentation involving the skin, hair, eyes, and ☆catecholaminergic brain nuclei (which produce a dark pigment known as neuromelanin) results from the inhibitory effect of excess phenylalanine on melanin synthesis.
regulation by fructose-2,6-bisphosphatePFK-2(active in fed state) increase the production of fructose-2,6-bisphosphate (from fructose-6-phosphate) which in turn increase the activity of PFK-1→ ↑glycolysis
fasting state→ ↑glucagon→→ ↑fructose bisphosphatase-2, ↓phosphofructokinase-2→ less glycosis, more gluconeogenesis
fed state→ ↑insulin→→ ↓FBPase-2, ↑PFK-2→ more glycosis, less gluconeogenesis
