. Statements: (1) The major force responsible for protein secondary structure is hydrogen bonding. (2) Amino acids found in proteins are almost always L-isomers. (3) Conjugated proteins always contain one or more prosthetic groups. a. All three statements are true. b. Two of the three statements are true. c. Only one of the statements is true. d. None of the statements are true.

a. All three statements are true.

Explanation:

The major force responsible for protein secondary structure is hydrogen bonding- Secondary structure of proteins are defined by the pattern of HYDROGEN BONDS between the hydrogen of the amino group and oxygen atoms of the carboxyl group in the peptide backbone.

Amino acids found in proteins are almost always L-isomers- All the twenty naturally occurring amino acids comprise of the L- isomer forms.

Conjugated proteins always contain one or more prosthetic groups-Most proteins contain only amino acids and no other chemical groups. These types are called simple proteins.

Some types of proteins undergo hydrolysis and yield some other chemical component in addition to amino acids.These types are called conjugated proteins. The non-amino part of a conjugated protein is usually called its prosthetic group and without this prosthetic group the protein is meant to be a simple protein and not a conjugate protein.Most prosthetic groups are formed from vitamins.

a. All three statements are true.

Explanation:

1. Hydrogen bonding is a major force that helps to stabilize protein structure, either the secondary or tertiary. The bond is a link among series of polypeptide chains due to hydrophobic interactions.

2. Most amino acids in proteins are in the form of the L (Laevorotatory)- isomers, which are the basis of proteins. The L- isomer proteins are of great use to biological tissues and cells.

3. A conjugate protein has a non-amino acidic part called prosthetic groups.  These groups are formed from vitamins which are required for appropriate  functioning of some proteins.

Therefore, all three statements are true.

well the answer is 2!