IST3C/IST3D- If an animal cell suddenly loses the ability to produce GTP, what will most likely happen to its signaling system?

Question

BlackTom AI · Accepted Answer

Restating the question: IST3C/IST3D asks what happens to an animal cell's signaling system if the cell suddenly loses the ability to produce GTP.

Option given: 'It will not be able to activate G proteins on the cytoplasmic side of the plasma membrane.'

Analysis of the option:
- G proteins, such as the heterotrimeric G proteins involved in G protein-coupled receptor (GPCR) signaling, rely on GTP binding to the Gα subunit to become active. When a receptor is activated, GDP is exchanged for GTP on Gα, causing Gα-GTP to dissociate from Gβγ and to propagate downstream signaling.
- If the cell cannot produce GTP, the exchange of GDP for GTP cannot occur. As a result, the Gα subunit cannot become GTP-bound and activated. Consequently, the G protein cannot propagate the signal on the cytoplasmic side of the membrane.
- This would blunt or abolish downstream signaling that depends on G protein activation, such as adenylyl cyclase activation or phospholipase C pathways, depending on the specific GPCR system involved.

Conceptual considerations:
- The core requirement for activation of G proteins is the availability of GTP. Without GTP, activation cannot occur, regardless of receptor status.
- Any signaling steps that depend on the Gα-GTP or Gβγ active forms would be impaired, leading to reduced or blocked signal transduction.

Notes about missing alternatives:
- The provided dataset does not list other answer choices to contrast against, so direct evaluation of alternative hypotheses (e.g., effects on GDP-bound G proteins, receptor activation, or downstream effectors independent of GTP) cannot be performed here. If additional options were present, each would need its own justification or refutation within the same logical framework.

In summary, the statement correctly identifies the critical dependency of G protein activation on GTP availability. Without GTP production, G proteins cannot become active on the cytoplasmic side of the plasma membrane, effectively silencing GPCR-mediated signaling at its source.

IST3C/IST3D- If an animal cell suddenly loses the ability to produce GTP, what will most likely happen to its signaling system?单项选择题

类似问题

Which ONE of the following statements is MOST ACCURATE? 以下哪个说法最准确？

G-proteins

Which combination of G-protein subunit(s) has highest affinity for adenylate cyclase (AC)?

The occupation of a G-protein coupled receptor with a ligand promotes the:

In a signal transduction cascade using G-proteins and cAMP, which is not a signal amplification step?

Is the following statement true or false? In the products of methylation-hydrolysis, every -OH group corresponds to the position of a glycosidic bond in the starting polysaccharide.

Which of the follwoing structures represents amylopectin?

Which of the following is true about an aldopentose?I. It is a monosaccharide.II. It contains a CHO groupIII. It is a disaccharide.IV. It is an oligosaccharide.

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单