Protein Structure and Function Quiz

Proteins form by amino acids undergoing condensation reactions, in which the amino acids lose one water molecule per reaction in order to attach to one another with a peptide bond.

Proteins fold into specific spatial conformations driven by a number of non-covalent interactions, such as hydrogen bonding, ionic interactions, Van der Waals forces, and hydrophobic packing.

To understand the functions of proteins at a molecular level, it is often necessary to determine their three-dimensional structure, as this provides insight into their biological function.

<p>Structural biology employs techniques such as X-ray crystallography, NMR spectroscopy, cryo-electron microscopy (cryo-EM), and dual polarisation interferometry to determine the structure of proteins.</p> Signup and view all the answers

<p>A superdomain is a conservative combination of several domains that occur in different proteins, which may evolve as a single unit.</p> Signup and view all the answers

<p>Structural and sequence motifs refer to short segments of protein three-dimensional structure or amino acid sequence that are found in a large number of different proteins.</p> Signup and view all the answers

<p>Supersecondary structure refers to a specific combination of secondary structure elements, such as β-α-β units or a helix-turn-helix motif.</p> Signup and view all the answers

<p>A protein fold refers to the general protein architecture, while protein topology is a related concept that describes the arrangement of secondary structures in a protein.</p> Signup and view all the answers

<p>Proteins are not static objects but rather populate ensembles of conformational states, allowing them to function as nanoscale biological machines within cells.</p> Signup and view all the answers

<p>Examples include motor proteins such as myosin, kinesin, and dynein, which are responsible for muscle contraction, cargo transport within cells, and axonemal beating of motile cilia and flagella.</p> Signup and view all the answers

<p>Intrinsically disordered proteins exist and function in a relatively 'disordered' state lacking a stable tertiary structure, unlike relatively stable tertiary structures that experience conformational changes after being affected by interactions with other proteins.</p> Signup and view all the answers

<p>Flexible linkers allow the mobile protein domains connected by them to recruit their binding partners and induce long-range allostery via protein domain dynamics.</p> Signup and view all the answers

<p>The four levels of protein structure are primary, secondary, tertiary, and quaternary.</p> Signup and view all the answers

<p>The primary structure is the sequence of amino acids in a polypeptide chain.</p> Signup and view all the answers

<p>The two types of secondary structure are α-helix and β-sheets.</p> Signup and view all the answers

<p>The tertiary structure is the three-dimensional folding of a single protein molecule.</p> Signup and view all the answers

<p>The quaternary structure involves the aggregation of multiple polypeptide chains.</p> Signup and view all the answers

<p>Quaternary structures can form dimers, trimers, tetramers, or pentamers.</p> Signup and view all the answers

<p>Proteins consist of structural units like domains, motifs, and folds.</p> Signup and view all the answers

<p>Structural domains are self-stabilizing elements that often fold independently.</p> Signup and view all the answers

<p>Yes, domains can be swapped between proteins to create chimera proteins.</p> Signup and view all the answers

<p>The sequence of a protein is determined by the corresponding gene and is unique to that protein, defining its structure and function.</p> Signup and view all the answers