B. 2.883 million kilometer
Answer: Option E) polar
Amino acid-derived and peptide hormones are unable to diffuse across a cell membrane because they are polar
Explanation:
Amino acid-derived and peptide hormones such as serotonin, epinephrine, dopamine etc, are unable to diffuse across a cell membrane because they consist of several repeating units of amino acids with positively charged or negatively charged side chains.
Thus, the side chains make these hormones water-loving (hydrophilic), and impassable to the hydrophobic layer of the cell membrane.
Answer:
substitution - a base was changed
Explanation:
The nucleotide sequence CTT was changed to the sequence CAT. The T was substituted with an A. This changed the encoded amino acid from Glu to Val.
An insertion is where an additional base is added (e.g. if the sequence changed from CTT to CATT)
A deletion is when a base is lost (e.g. if the sequence changed from CTT to CT)
