Please answer below quesitions of Molecular biology from 21

Please answer below quesitions of Molecular biology from 21 to 26. Do not plagiarized answer from any web-sources, otherwise it will reported as a spam.

21. Define/differentiate the following from one another: Motif, Domain, Multi-domain, Quaternary structure 22. Define the following domains: SH2, SH3, Bromo, Chromo, PTB, SNARE, EF-Hand 23. Why are eukaryotic proteins on average bigger than prokaryotic proteins? 24. What is the role of protein domains, and why do most proteins contain more than one domain? 25. Why does fructose 1,6-bisphosphate bind to pyruvate kinase? What is this called? 26. Explain the overall structure of phosphofructokinase 2 /fructose bisphosphatase 2, noting why the protein interface is important, and the role of serine 32

Solution

Answer to question number 21:

Motif:

Motifs are super secodary structures with non designated biological function. It is formed by the chain-like polypeptides or nucleic acids. In DNA it provided a binding site for proteins and transcription factors.

E.g, Zn motif

Domain:

Domain are the conserved structural and functional part of a protein. They perform specific functions by forming a compact three dimensional structure. E.g, Src homology 3

Multi domain:

Proteins comprising for several domains are multi domain.

E.g., Nck, a cytoplasmic protein.

Quaternary Structure:

Many protein subunits which cluster together to form a stabilized aggregate protein complex, by bonding interactions like hydrogen-bonding, disulfide-bridges and salt bridges, forms the quaternary structure.

E.g., Hemoglobin