In trimetric G proteins the only function of the bamma y complex is to allow reactivating of the a subunit ? True or false

Trelstar® is an injectable formulation of polylactide-co-glycolide (PLGA) microspheresencapsulating triptorelin palmoate (Mw 13115 Da), a synthetic decapeptide agonist analog ofgonadotropin releasing hormone (GnRH). The medicine is used in treatment of patients withprostate cancer. The pharmacokinetics of triptorelin palmoate as free drug follows a 3 compartmentmodel with drug half-lives estimated to be 6 minutes, 45 minutes, and 3 hours, respectively. Threedifferent dosing intervals of Trelstar® are available in clinic: 1 month (3.75 mg), 3 month (11.25mg) and 6 month (containing 22.5 mg of drug).Discuss how encapsulation into PLGA microspheres improves patient therapy with triptorelinpalmoate, and how three dosing intervals available in clinic may have been achieved bymodifications in the formulation

The a and ß subunits of hemoglobin bear a remarkable structural similarity to myoglobin. However, certain residues that are hydrophilic in myoglobin are hydrophobic in the subunits of hemoglobin. Why might this be the case? O Hydrophilic residues on the surface of myoglobin form ionic interactions with similar regions on other myoglobin molecules. O Hydrophobic residues on the surface of hemoglobin subunits interact with similar regions on the other subunits through van der Waals interactions. Hemoglobin forms long, extended structures that feature repeated sequences, whereas myoglobin forms globular structures. Myoglobin is a water-soluble protein, whereas hemoglobin is found in the hydrophobic environment of membranes.

Substrate A has a Km of 45uM and a kcat of 100/s with trypsin and a Km of 540mM and a kcat of 2/s with chymotrypsin. Substrate A is a better substrate of [trypsin/chymotrypsin] and likely contains a/an/some [aromatic/acidic/basic] residues(s) in its sequence. Chymotrypsin contains a [glycine/serine/aspartate] in its specificity pocket which likely [repel/attract] the residues in substrate A.

Is there anyway to draw a visual diagram for this as the explanation does not make sense how can 2 aspartates interact with each other under physiological pH?

Explain the function(s) of Hsp90. Name two factors which lead to the increase of this protein in cells.

Starting from the situation below, explain the next immediate steps that occur after the agonist ligand binds to the GPCR. Describe what happens in terms of the GTP and the heterotrimeric G protein structure. www www Ligand α В GTP ZAN Y Copyright ©2009 Pearson Education, Inc. GDP

Using the information given, determine the Kd for the binding of HABA to BSA. B= y-intercept (E bound)  2457.6x (E unbound) Data for the binding of HABA to BSA y = 4E-06x + 5.2134               R² = 0.928

Ligand binding to proteins may occur with varying strengths; some ligands bind tightly to proteins while others bind less tightly. The strengths of reversible binding are determined experimentally by varying concentrations of ligands, and measuring the saturation of the protein in the various ligand concentrations. One such laboratory study investigated the binding of a hormone to three different receptor proteins in the cell membrane. The data collected are shown in the table below: 1) Provide a brief explanation as to why ligand binding to proteins must be a reversible process.  2)  Calculate the dissociation constant (Kd) for the hormone binding to each of the three proteins.

Which of the following statements are descriptions of metal ion catalysis or examples of metal ion catalysis? Choose all correct answers a Zn²+ cofactor may properly orient the substrate in the active site through ionic interactions. a covalent bond forms between enzyme and substrate lowers the energy or stabilizes the transition state or intermediate catalyst retains its original form after reaction occurs catalysts may participate in oxidation-reduction reactions by changes in the oxidation state