Question

Ras is most similar to:

Please choose the correct answer from the following choices, and then select the submit answer button.


-ion channels.

t-he beta subunit of three-subunit G proteins.

-receptor kinases.

t-he gamma subunit of three-subunit G proteins.

t-he alpha subunit of three-subunit G proteins.

Answer 1

Ras is most similar to the alpha subunit of three-subunit G proteins, functioning in cellular signal transduction, and is involved in critical cellular processes including protein expression and cell division.

Step-by-step explanation:

Ras is most similar to the alpha subunit of three-subunit G proteins. The Ras protein is part of a family of small GTPases that are involved in cellular signal transduction. When a signalling molecule, such as epidermal growth factor (EGF), binds to its receptor tyrosine kinase, it promotes an increase in cellular responses including protein expression, cellular metabolism, and cell division. Ras behaves similarly to the alpha subunit of heterotrimeric G-proteins in that when the G-protein-linked receptor receives a signal, GDP is exchanged for GTP on the alpha subunit, leading to dissociation from the beta and gamma subunits, which then triggers a cellular response. Mutations in RAS, particularly impairing its GTPase activity, can lead to uncontrolled cell proliferation, which is a characteristic of cancer.