9. Sodium channels are designed to only allow positively charged sodium ions (Na*) to enter the cell. Negatively charged

[answerhappygod]

9 Sodium Channels Are Designed To Only Allow Positively Charged Sodium Ions Na To Enter The Cell Negatively Charged 1 (66.02 KiB) Viewed 76 times

9. Sodium channels are designed to only allow positively charged sodium ions (Na*) to enter the cell. Negatively charged carboxyl groups line the channel to attract the positively charged Na* and repel negatively charged ions. The channel is also just large enough to allow a single hydrated Na* pass through. Tetrodotoxin (TTX), a particularly powerful neurotoxin found in pufferfish and on the skin of some newt species, blocks the conduction of nerve impulses by specifically acting on sodium channels in nerve cells. This results in the nervous system shutting down and respiratory paralysis causes death in the victims. TTX contains the amino acid, guanine, which has a positively charged amino group. Using the image below, answer the following questions: Na* OH₂ TTX a. Diagram a functioning sodium channel. Use arrows to show directional flow and charges in your drawing. b. In a second diagram, draw how TTX would prevent sodium ions from entering the cell. c. Explain how TTX is acting to create a non-functioning sodium channel.