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4 years ago

What are the respective roles of grb2 and sos in the activation of ras by egfr?

Chemistry

1 answer:

valina [46]4 years ago

5 0

Answer:

Role is defined below

Explanation:

A small GTP-binding protein, is an important module of the signal transduction pathway used by growth factors to initiate cell growth and differentiation. Cellular activation with growth factors such as epidermal growth factor (EGF) induces Ras to move from an inactive state linked to GDP to an active state linked to GTP. In recent times, a mixture of genetic and biochemical studies has resulted in the elucidation of a signaling pathway that leads from growth factor receptors to Ras. After joining EGF, the EGF receptor tyrosine kinase is activated, which leads to receptor auto phosphorylation in multiple tyrosine residues. Signaling proteins with homology domains Src 2 (SH2) then bind to these phosphorylated residues in tyrosine, initiating multiple signaling cascades. Distinct of these SH2 area proteins, Grb2, exists in the cytoplasm in a preformed complex with a second protein, Son of Sevenless (Sos), which can catalyze the Ras GTP / GDP exchange. After stimulation of the growth factor, the phosphorylated EGF receptor with tyrosine binds to the Grb2 / Sos complex and translocates it to the plasma membrane. It is believed that this translocation brings Sos closer to Ras, which leads to the activation of Ras. In dissimilarity, the insulin receptor does not bind Grb2 directly, but rather induces the tyrosine phosphorylation of two proteins, the substrate-1 insulin receptor and Shc, which bind to the Grb2 / Sos complex. Once Ras is activated, a cascade of protein kinases that are important in a myriad of growth factor responses is stimulated.

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Calculate Delta H in KJ for the following reactions using heats of formation:

lozanna [386]

Answer:

$\Delta H\textdegree = -2856.8\;\text{kJ}$ per mole reaction.

$\Delta H\textdegree = -22.3\;\text{kJ}$ per mole reaction.

Explanation:

What is the standard enthalpy of formation $\Delta H_f\textdegree{}$ of a substance? $\Delta H_f\textdegree{}$ the enthalpy change when one mole of the substance is formed from the most stable allotrope of its elements under standard conditions.

Naturally, $\Delta H_f\textdegree{} = 0$ for the most stable allotrope of each element under standard conditions. For example, oxygen $\text{O}_2$ (not ozone $\text{O}_3$ ) is the most stable allotrope of oxygen. Also, under STP $\text{O}_2$ is a gas. Forming $\text{O}_2\;(g)$ from itself does not involve any chemical or physical change. As a result, $\Delta H_f\textdegree{} = 0$ for $\text{O}_2\;(g)$ .

Look up standard enthalpy of formation $\Delta H_f\textdegree{}$ data for the rest of the species. In case one or more values are not available from your school, here are the published ones. Note the state symbols of the compounds (water/steam $\text{H}_2\text{O}$ in particular) and the sign of the enthalpy changes.

$\text{C}_2\text{H}_6\;(g)$ : $-84.0\;\text{kJ}\cdot\text{mol}^{-1}$ ;
$\text{CO}_2\;(g)$ : $-393.5\;\text{kJ}\cdot\text{mol}^{-1}$ ;
$\text{H}_2\text{O}\;{\bf (g)}$ : $-241.8\;\text{kJ}\cdot\text{mol}^{-1}$ ;
$\text{PbO}\;(s)$ : $-217.9\;\text{kJ}\cdot\text{mol}^{-1}$ ;
$\text{PbO}_2\;(s)$ : $-276.6\;\text{kJ}\cdot\text{mol}^{-1}$ ;
$\text{Pb}_3\text{O}_4\;(s)$ : $-734.7\;\text{kJ}\cdot\text{mol}^{-1}$

How to calculate the enthalpy change of a reaction $\Delta H_\text{rxn}$ (or simply $\Delta H$ from enthalpies of formation?

Multiply the enthalpy of formation of each product by its coefficient in the equation.
Find the sum of these values. Label the sum $\Sigma (n\cdot \Delta_f(\text{Reactants}))$ to show that this value takes the coefficients into account.
Multiply the enthalpy of formation of each reactant by its coefficient in the equation.
Find the sum of these values. Label the sum $\Sigma (n\cdot \Delta_f(\text{Products}))$ to show that this value takes the coefficient into account.
Change = Final - Initial. So is the case with enthalpy changes. $\Delta H_\text{rxn} = \Sigma (n\cdot \Delta_f(\textbf{Products})) - \Sigma (n\cdot \Delta_f(\textbf{Reactants}))$ .

For the first reaction:

$\Sigma (n\cdot \Delta_f(\text{Reactants})) = 4\times (-393.5) + 6\times (-241.8) = -3024.8\;\text{kJ}\cdot\text{mol}^{-1}$ ;
$\Sigma (n\cdot \Delta_f(\text{Products})) = 2\times (-84.0) + 7\times 0 = -168.0\;\text{kJ}\cdot\text{mol}^{-1}$ ;
$\begin{aligned}\Delta H_\text{rxn} &= \Sigma (n\cdot \Delta_f(\textbf{Products})) - \Sigma (n\cdot \Delta_f(\textbf{Reactants}))\\ &= (-3024.8\;\text{kJ}\cdot\text{mol}^{-1}) - (-168.0\;\text{kJ}\cdot\text{mol}^{-1})\\ &= -2856.8\;\text{kJ}\cdot\text{mol}^{-1} \end{aligned}$ .

Try these steps for the second reaction:

$\Delta H_\text{rxn} = -22.3\;\text{kJ}\cdot\text{mol}^{-1}$ .

6 0

3 years ago

Cómo se denomina el calor que ponen en juego los sistemas materiales cuando cambian su temperatura? Seleccione una: a. Calor cin

Law Incorporation [45]

Answer:

La respuesta correcta es: b. Calor sensible

Explanation:

Al absorber calor, un sistema puede: aumentar su temperatura o cambiar de fase (es decir, pasar de un estado de agregación a otro). Los cambios de fase se producen a temperatura constante, por lo que el calor involucrado se denomina calor latente. Por ejemplo, cuando el agua líquida pasa a vapor por calentamiento a la temperatura de ebullición, esta temperatura se mantiene constante hasta que toda la masa de agua pasa al estado vapor. En cambio, cuando el sistema absorbe calor cambiando su temperatura pero permaneciendo en el mismo estado de agregación (por ejemplo, cuando calentamos agua líquida por debajo de la temperatura de ebullición), el calor involucrado se denomina calor sensible.

6 0

3 years ago

Fran finds a dark-colored rock that she identifies as basalt. Which property gives the rock its dark color?

romanna [79]

Answer:

Mineral Content.

Explanation:

shape has nothing to do with the color displayed.

Nor does the grain size.

I don't know what banding is. Whatever it is, it is not the answer.

D: mineral content.

8 0

3 years ago

Read 2 more answers

Chemical reactions guided reading and study describing chemical reactions what are chemical equations ci 2.2

vlada-n [284]

Answer:

i dont really know this one

Explanation:

7 0

3 years ago

Using a steel framework with masonry sheathing, the ________, designed by Louis Sullivan, is thought by many to be the first gen

ahrayia [7]

Answer:

Louis Sullivan designed Wainwright Building by using steel framework with masonry sheathing.

Explanation:

Louis Henry Sullivan is called as 'father of modernism' was an architect who build the Wainwright Building.

He took the idea from Marcus Vitruvius Pollio and used cast in iron or called terra cotta that contain vines and ivy that gives more geometric design.

Terra cotta is lighter and easy to use than stone masonry.

All of these materials are used in constructing Wainwright Building,Guaranty Building.

As he first invent to design the remarkable designs,he is called as father of American skyscraper

7 0

4 years ago