The body system responsible for eliminating waste as well as maintianing blood pressure, electrolyte, and acid-base balance is the

A. Cholesterols: Cholesterol is a lipid molecule involved in cell membrane structure and as a precursor for steroid hormones, not as a catalyst for biochemical reactions.

B. Triglycerides: Triglycerides are fats used primarily for energy storage and insulation, and they do not function as enzymes.

C. Proteins: Most enzymes are proteins composed of amino acids. Their three-dimensional structure allows them to bind substrates and catalyze biochemical reactions efficiently, making them essential for metabolic processes.

D. Carbohydrates: Carbohydrates serve as energy sources and structural molecules but do not act as enzymes to catalyze reactions.

A. Hold carbohydrates and DNA in their 3-D shape: Carbohydrates rely more on glycosidic bonds and branching patterns for their structure, while hydrogen bonding has only a minor role. DNA, however, depends heavily on hydrogen bonds between nitrogenous bases for stability.

B. Hold proteins and DNA in their 3-D shape: Proteins maintain their secondary and tertiary structures through hydrogen bonds between amino acid side chains and peptide backbones. DNA depends on hydrogen bonds between complementary bases, which provide stability while still allowing strand separation during replication.

C. Hold carbohydrates and triglycerides in their 3-D shape: Triglycerides are primarily stabilized by ester bonds and hydrophobic interactions. Carbohydrates do not depend significantly on hydrogen bonds for their three-dimensional organization.

D. Hold proteins and RNA in their 3-D shape: While RNA can fold into complex structures stabilized partly by hydrogen bonds, proteins and DNA are more classically described as relying on hydrogen bonding for maintaining stable 3-D conformations.