Coiling & folding of a polypeptide chain of secondary structure of protein are the result of ___________________ bond.

______________ is a molecule that contains two functional groups; one having positive charge and the other one having negative charge in solution of pH 7.

Steroid molecules do not contain fatty acids.

• True

• False

Pyrimidines have a single six-membered ring.

• True

• False

Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?

• water's change in density when it condenses

• water's ability to dissolve molecules in the air

• the release of heat by the formation of hydrogen bonds

• the absorption of heat by the breaking of hydrogen bond

The diagram provides some information concerning proteins.

Which of the following represents A?

• sequence of ATP molecules

• sequence of amino acids

• sequence of simple sugars

• sequence of starch molecules

The structures that forms the main component of the exoskeleton of arthropods and certain fungal cell wall is

• cutin

• chitin

• murein

• cellulose

Choose the correct match regarding functional groups.

• - OH : thiol group

• - COOH : methyl group

• - C=O : carbonyl group

• - CH₃ : carboxyl group

Two monomers of nucleic acid are held together by

• ester bond

• peptide bond

• nucleotide bond

• phosphodiester bond

Which nucleic acid below might contain the triplet bases of CAT?

• RNA

• rRNA

• DNA

• tRNA