What are the two gases that animals exchange and their surroundings
a. oxygen and nitrogen
b. nitrogen in helium
c. hydrogen and carbon dioxide
d. corbin the outside and oxygen

Which of the following statements is true regarding a basic amino acid? a.) the hydrophilic r group of a basic amino acid will be located on the interior of a protein b.) the positively charged r group of a basic amino acid could bind dna c.) the r group of a basic amino acid would only be able to form covalent bonds with other molecules d.) a basic amino acid would be considered both polar and hydrophobic e.) all of the above