Protein Metabolism

The building block of protein is

• DNA

• RNA

• amino acids

• nitrogen

The following statements about amino acids are true except

• the amino group is positively charged

• an amino acid is a zwitterion

• the carboxyl group is negatively charged

• all amino acids are electrically neutral

The amino acid sequence in a protein refers to

• primary structure

• secondary structure

• tertiary structure

• quaternary structure

Protein synthesis take place in the

• mitochondria

• lysosome

• ribosome

• nucleus

During transamination, amino acid transfer their amino group to

• alpha-keto acid

• alpha-ketoglutarate

• glutamate

• pyruvate