The diagram shows the structure of the protein CXCL12.

[Source: Lu, J., Chatterjee, M., Schmid, H. et al. CXCL14 as an emerging immune and inflammatory modulator.
J Inflamm 13, 1 (2016). https://doi.org/10.1186/s12950-015-0109-9 Distributed under the terms of the
Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/).]

Which chemical group is found at X?

A. NH₂

B. NOH

C. COH

D. COOH

The image shows the structure of the protein hemoglobin

[Source: Hemoglobin molecule, Microbiology ID: [email protected] OpenStax Microbiology
https://cnx.org/contents/[email protected] and https://commons.wikimedia.org/wiki/File:OSC_Microbio_07_04_
hemoglobin.jpg Licensed under a Creative Commons Attribution 4.0 International License,
https://creativecommons.org/licenses/by/4.0.]

What level of protein structure bonds the α and β chains together?

A. Primary

B. Secondary

C. Tertiary

D. Quaternary

Which statement applies to the tertiary structure of enzymes?

A. Tertiary structure is the sequence of amino acids in an enzyme.

B. Some enzymes do not have a tertiary structure.

C. An example of tertiary structure in an enzyme is the alpha helix.

D. A change in the tertiary structure of an enzyme may result in a change in the structure of the active site.

Succinate dehydrogenase is an enzyme that catalyses the oxidation of succinic acid. If malonic acid is added to the mixture, the rate of reaction is reduced. An increase in succinic acid will increase the rate of reaction again. For this system, which term best describes malonic acid?

A. Substrate

B. End product

C. Non-competitive inhibitor

D. Competitive inhibitor    

Which of the molecules contain peptide bonds or are sugar molecules?

The table shows the mass of different types of fat in some foods.

Which oil would be least recommended for inclusion in the human diet?

A. Palm oil

B. Canola oil

C. Sunflower oil

D. Partially hydrogenated soybean oil