March 6 Flashcards
Where do the ETC and TCA cycle take place?
ETC in inner mito MB, TCA is in the mito matrix
The diauxic shift is when shifts from (aerobic/anerobic) ____1___ (fermentation) to ___2____ (respiration). What food source do they use and turn it into in each senario
1 = anerobic
2 = aerobic
They start with glucose (fermentable sugar) and produce ethanol. Then switch to aerobic, and use other carbon sources and burn it into CO2 and H2O
When glucose levels decrease many yeast genes have different expression levels. What are 3 processes that are upregulated, and the 1 big one that is down regulated when glucose levels start to decrease?
Yeast will upregulaate glycogen metabolism (store some of glucose), upregulate glyoxalate cycle (using other carbon cycles), and ETC (respiration when use other carbon sources)
It will downregulate tRNA synthetase and everythin involved in transcription and translation as making proteins takes a lot of energy
Metformin is a derivative of _____.
Guanidine
What does metformin do (simple answer in like 5 words)
It promotes glucose uptake, lowers hepatic glucose output.
What 3 cell types uptake glucose, which type(s) export it?
Adipose, hepatocytes, skeletal muscle. Only liver can export it, muscle burns it for energy and adipose has it part of triglyceride
What is the direct target of metformin? What occurs because of this?
It targets mitochondrial complex 1, prevents NADH from entering and donating electron so it can be passed along ETC. Result is less ATP produced, so more ADP and AMP in cells, so more activation of AMP-activated protein kinase (AMPK).
The ____ centers are in proteins that pass on electrons in the ETC?
Fe-S
Acetyl-CoA carboxylase (ACC) is allosterically regulated by 3 main things. What are they, up/down regulate, and what does it tell the enzyme? Also what does the enzyme do?
ACC will add CO2 to acetyl-CoA to form malonyl-CoA. Citrate will upregulate it (signaling lots of carbon available). 5’ AMP (energy status low) and palmitoyl-CoA (product of lipid metabolism) downregulate it
What do we know about kinase for HMG-CoA reductase adn ACC? On what AA does it phosphorylate?
When titrating in AMP, can see that the same kinase activity increases, indicating same enzyme phosphorylates ACC and HMG-CoA reductase on serine.
What drug inhibits HMG-CoA reductase, what is effect of this? How does it work?
It is statins, they reduce cholesterol production. It mimics HMG-CoA, binds to the enzyme and inhbits it
How many subunits does AMPK have? This knowledge indicates that AMPK is a homolog of what yeast enzyme)? What do the subunits for AMPK have in terms of domains that give them the function they have? What is the yeast version of these subunits called?
It has 3 subunits, just like the Snf1 Complex.
alpha (Snf1) = kinase domain (with activation loop), and binding domain for subunit Beta and gamma
Beta (SIF)= glycogen binding and binding domain for alpha and gamma
Gamma (Snf4) = CBS domains that bind to AMP, ADP, and ATP. They outcompete eachother, then once AMP is high enough, it binds enough to activate the kinase subunit.
What does CBS domain in Snf4/gamma subunit of yeast Snf1 complex/human AMPK stand for? Binds to what,, is this domain widespread?
Cystathione beta synthase. Binds to adenosyl part of AMP, ADP, ATP. It will give whatever protein it is part of an idea of the cell energy status. It is very widespread, there are different isoforms of it corresponding to different diseaseses if mutated as well
