Term
| what happens when glucose is abundant? When it is lacking? |
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Definition
| When abundant: glycolysis, when not: gluconeogenesis. |
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Term
| When you have low blood glucose and need fast response, what happens? |
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Definition
| PFK2 is phosphorylated and pyruvate kinase gets phosphorylated so it gets all horny and goes after shit so it can catalyze key steps in glycolysis and gluconeogenesis. This has to do with glucagon and the Gs pathway. |
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Term
| What does the PEP carboxy kinase (PEPCK) gene do? |
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Definition
| Its product is the rate-limiting step of gluconeogenesis. Long term activity of the gluconeogenesis pathway is controlled by the transcription levels of the PEPCK gene. |
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Term
| what are the three ways that a 5' cap does shit? |
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Definition
| 1. It protects from exonucleases by making a 5' to 5' bond, so that the exonuclease can't attack an open 5'. 2. helps with export to the nucleus. 3) helps with getting into the ribosome |
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Term
| How is the polyA tail useful? |
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Definition
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Term
| Besides a higher melting point, why does transcription differ in regions where there is alot of C-G binding? |
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Definition
| This has to do with CpG islands and methylation. A good example of this is L1 retrotransposons in eukaryotes: which are heavily methylated to discourage RT. |
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Term
| what happens when there is chronically low glucose? |
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Definition
| Glucocorticoids are produced by the adrenal cortex which causes long-term upregulation of the PEPCK gene. |
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Term
| What happens to PEPCK when there is high glucose and what causes this? |
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Definition
| PEPCK transcription is inhibited by high glucose levels because of insulin. |
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Term
| What does PFK2 do in low blood glucose? |
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Definition
| Glucagon binds at GPCR. Adenylyl cyclase is activated. cAMP is increased which activates PKA. PKA phosphorylates PFK2, INACTIVATING IT-->then gluconeogensis happens. |
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Term
| what does Pyruvate kinase do with low glucose? |
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Definition
| Glucagon binds at GPCR. Adenylyl cyclase is activated. Increase cAMP, causing elevation of PKA. PKA phosphorylates glycolysis enzyme pyruvate kinase--TURNING ITOFF. This stops glycolysis and STARTS GLUCONEOGENESIS. |
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Term
| what are some positive regulators of PEPCK expression? |
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Definition
| So like after glucagon binds, shit goes DOWNNNNNN. GPCR gets bound, adenylyl cyclase is secondarily activated which increase levels of cAMP which activates PKA. yeah baby. The catalytic subunit of PKA dissociates and goes to the nucleus where if phosphorylates CRE-Binding Protein (CREB). CREB then binds to the DNA enhancer sequence CRE (cAMP response element). It also interacts with CBP/300 which makes CREB stimulate TXN babyyyyyy |
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Term
| Where does glucocorticoid do? |
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Definition
| It binds to glucocorticoid receptor protein, which is in the cytoplasm. This exposes the NLS and the GR-GC complex goes to the nuclus and functions as a transcription factor. THIS BINDS TO THE RESPONSE ELEMENT on the DNA. Transcription of PEPCK gets activated. |
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Term
| What does insulin do for PEPCK? |
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Definition
| insulin acts through a receptor tyrosine kinase (RTK) to inhibit gluconeogenesis and increase glycogen storage. basically, as a result of insulin binding the RTK, a REPRESSSOR bINdS TO thE INSULIN RESPONSE ELEMENT, which represses transcription of PEPCK. this is a strong ass effect, beotch. |
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Term
| in what kind of cells are PEPCK expressed? if it isn't expressed in a certain type of cell, what causes it to not be expressed? |
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Definition
| Hypermethylation causes it to not be expressed in ALL CELLS besides THE LIVER. |
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