Part 2 Bio

1. TTX blocks voltage-gated _____ channels.

sodium (or $\text{Na}^+$)

2. When sodium channels open, _____ ions move into the neuron.

sodium (or $\text{Na}^+$)

3. The sodium-potassium pump moves 3 _____ out of the cell and 2 _____ into the cell.

sodium ($\text{Na}^+$); potassium ($\text{K}^+$)

4. The sodium-potassium pump requires _____ making it a form of _____ transport.

ATP; active

5. Passive transport moves substances from an area of _____ concentration to an area of _____ concentration.

high; low

6. A membrane protein that provides a pathway for ions to cross is called a _____ protein.

channel

7. The process of making mRNA from DNA is called _____.

transcription

8. The three stop codons are _____, _____, and _____.

UAA; UAG; UGA

9. The start codon for translation is _____.

AUG

10. A hydroxyl group consists of _____ and _____ and is generally _____.

oxygen; hydrogen; polar

11. DNA $\rightarrow$ mRNA is called _____ while mRNA $\rightarrow$ protein is called _____.

transcription; translation

12. If an mRNA lacks a proper stop codon, the ribosome does not receive the normal _____ signal.

termination (or stop)

13. As temperature decreases, the solubility of many solid substances in a liquid tends to _____.

decrease

14. TTX prevents normal nerve signaling because blocking sodium channels interferes with the _____ potential.

action

15. The $\text{Na}^+/\text{K}^+$ pump maintains ion _____ across the cell membrane.

gradients