The Na,K-ATPase in a Nerve Cell

question 38

Multiple Choice

The Na,K-ATPase in a nerve cell

• A)Maintains an electrical gradient such that the inside is negative with respect to the outside
• B)Maintains a concentration gradient for K⁺ such that diffusion forces favor movement of K⁺ into the cell
• C)Maintains an electrical gradient at the equilibrium potential of K⁺
• D)Transports an equal number of sodium and potassium ions
• E)Both maintains an electrical gradient such that the inside is negative with respect to the outside and transports an equal number of sodium and potassium ions are correct

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Definitions:

Transcription Factors

Proteins that regulate gene expression by binding to specific DNA sequences, thereby controlling the transfer of genetic information from DNA to mRNA.

Steroids

A large class of organic compounds with a characteristic molecular structure containing four rings of carbon atoms; they include many hormones, alkaloids, and vitamins.

Intracellular Receptors

Proteins located inside the cell that bind to certain substances and initiate a specific cellular response.

First Messenger

A signaling molecule that binds to a receptor on the cell surface, initiating a signal transduction process that leads to the formation of an intracellular second messenger.