LuisWk8ans - 2 nd messengers can be anything from gas,...

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Bio D103: Cell Biology Bio. Department Tutoring Winter 08: Week 8 Lectures 18-19 2/27/08 Wed. 1-3:00 SH157 1. GPCR--The α subunit of a G protein complex is mutated so that the GTP cannot be removed. Which statement is true? a. The αβγ complex would never disassociate b. The α complex could never interact with its target protein c. Downstream signaling would be constantly active d. The α subunit would not interact with the GPCR If the a subunit of a GPCR has GTP on it then it will readily disassociate from abY complex. Interaction with target proteins would occur because GTP is need for Ga to interact with downstream targets. IF GTP could NOT be phosphorylated then simply the GTPase Ga subunit would stay on. In order to reassociate with the GPCR’s bY subunits GTP must be hydrolyzed. 2. Which of the following statements is NOT true about second messengers a. They activate downstream transcription b. They can be an extracellular ligand c. They diffuse at variable rates d. They can be a gas
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Unformatted text preview: 2 nd messengers can be anything from gas, nucleotides, peptides, ionsbasically, almost any type of molecule. They activate downstream transcription by interacting with PKC/PKA, for example, and causing the catalytic subunit to dissociate from the regulatory subunit. 2 nd messengers diffuse in a concentration gradient from their source, and depending on inhibitory enzymes or sequestering proteins then they will diffuse throughout the cytosol are variable rates. 3. Please fill in the table. Pathway Does the receptor have intrinsic kinase activity Molecules that transduce the signal TGFB Yes 1 point SMAD 1 point Cytokine No 1 point STAT 1 point Receptor tyrosine kinase Yes 1 point MAP Kinases 1 point 4. 1,2-diacylglycerol (DAG) activates which of the following enzymes? a. Protein kinase C b. Protein kinase A c. Map kinase d. Tyrosine kinase PKA is part of Adenylyl cyclase pathway. MAP kinases are found on Tyrosine Kinase receptors....
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This note was uploaded on 05/28/2008 for the course BIO SCI D103 taught by Professor Suetterlin/macgregor during the Winter '08 term at UC Irvine.

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LuisWk8ans - 2 nd messengers can be anything from gas,...

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