Anthropods have exoskeletons
Answer: b. reaction 3
Explanation: When an enzyme is present in a reaction acts as a catalyst, increasing velocity of reaction and decreasing the activation energy, when not present an enzyme the reaction velocity is very low and implies high activation energy, being unfavorable to the system
Answer:
a mutation that blocks the GTPase activity of Ras
Explanation:
A G protein in inactive state is GDP bound but as soon as a guanine exchange factor (GEF) exchanges it with GTP it gets activated which means that in GTP bound state it is active. G - protein has endogenous GTPase activity. Upon interaction of GAP, the GTPase activity of this protein is exhibited. When GAP is present, hydrolysis of GTP into GDP occurs which leads to inactivation of G protein. A mutation which will block GTPase activity of Ras will therefore result in constitutive active signaling even in the absence of ligand binding to it's receptor. In such scenario, GTP will not be hydrolyzed into GDP so signaling will be up-regulated.
