IB Biology SL (Standard level)- 2024 – Practice Questions- All Topics
Topic 2.4 Proteins
Topic 2 Weightage : 20%
All Questions for Topic 2.4-Amino Acids, Peptide Bonds, Protein Structure, Denaturation, Gene ⇒ Polypeptide, Proteome, Protein Functions, The pH Scale, Fibrous vs Globular Proteins, Amino Acid Polarity
Question
The diagram shows the structure of E. coli ribonuclease HI, a bacterial protein consisting of one polypeptide chain.
Which level(s) of protein structure is/are shown?
A. Alpha helix only
B. Quaternary only
C. Primary and secondary
D. Secondary and tertiary
▶️Answer/Explanation
Ans: D
E. coli has several ribonucleases that are involved in RNA processing and degradation, such as RNase E, RNase G, RNase II, RNase III, and RNase T. The primary and secondary structures of these ribonucleases may vary depending on their functions and mechanisms.
Question
Which protein is identified with its function?
| Protein | Function |
A | collagen | provides strength and support for tissues and organs |
B | rhodopsin | enzyme found in tears |
C | insulin | raises blood glucose concentrations |
D | immunoglobulin | helps in blood clotting |
▶️Answer/Explanation
Ans: A
Collagen proteins are the most abundant proteins in the body. They provide structure, strength and support to various tissues, such as skin, bones, muscles, tendons and ligament. Collagen proteins are made of amino acids, mainly proline, glycine and hydroxyproline. They provide structure and support to these tissues. If you meant “coiled-coil proteins”, they are involved in many cellular processes such as vesicle transport, cell division, and muscle contraction.