Orders of Protein Structure

Hydrogen bonds stabilize the sheet-like structure of β-sheets formed by segments of polypeptide chains.

The tertiary structure refers to the three-dimensional conformation of a protein, whereas the primary structure is the linear sequence of amino acids.

Protein domains are structural parts of a protein that can fold and function independently, often determining functional characteristics.

<p>Quaternary structure involves the arrangement of multiple polypeptide subunits, exemplified by hemoglobin, which has four chains.</p> Signup and view all the answers

<p>Misfolded proteins can accumulate in cells, leading to potential cellular damage and are associated with diseases like Parkinson's and Alzheimer's.</p> Signup and view all the answers

<p>Chaperones guide proteins along proper folding pathways and protect them from factors that can inhibit the process.</p> Signup and view all the answers

<p>The tertiary structure is stabilized by interactions between side chains, including ionic interactions, disulfide bonds, and hydrogen bonds.</p> Signup and view all the answers

<p>Domains imply that a protein can contain distinct functional units that can operate independently within the protein structure.</p> Signup and view all the answers

<p>Denaturation is the loss of secondary and tertiary structures of a protein while retaining its primary structure, resulting in the unfolding of the polypeptide chain.</p> Signup and view all the answers

<p>The primary structure is defined by the linear sequence of amino acid residues linked by peptide bonds.</p> Signup and view all the answers

<p>Physical factors include high temperature and radiation, while chemical factors involve strong acids, alkalis, and urea.</p> Signup and view all the answers

<p>Polypeptide subunits in quaternary structures interact primarily via non-covalent interactions such as hydrogen bonds.</p> Signup and view all the answers

<p>Denaturation leads to a loss of biological activity in enzymes and hormones, and changes protein's antigenic properties.</p> Signup and view all the answers

<p>Cells tag misfolded proteins for degradation, but this quality control system can fail, leading to protein accumulation.</p> Signup and view all the answers

<p>Genetic diseases may arise from proteins with abnormal amino acid sequences, causing improper folding and loss of function.</p> Signup and view all the answers

<p>Understanding protein folding is significant because improper folding can lead to aggregates that are implicated in Alzheimer's disease.</p> Signup and view all the answers

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

<p>Hair treatments like perms use strong chemicals to break disulfide bonds, causing hair to lose its curly texture permanently.</p> Signup and view all the answers

<p>The secondary structure is stabilized by hydrogen bonds formed between carbonyl O of one amino acid and the amino H of another.</p> Signup and view all the answers

<p>Peptide bonds remain intact during denaturation, allowing the primary structure to be retained.</p> Signup and view all the answers

<p>The α-helix is a rigid, spiral structure with a tightly packed polypeptide backbone and side chains extending outward.</p> Signup and view all the answers

<p>Temperatures above 70°C typically cause protein denaturation, leading to loss of structure and function.</p> Signup and view all the answers

<p>Simple proteins are classified based on chemical composition; they consist solely of amino acids without any non-peptide components.</p> Signup and view all the answers

<p>Protein folding is vital as it determines the protein's three-dimensional structure and function.</p> Signup and view all the answers

<p>Strong acids and alkalis disrupt the non-covalent bonds, leading to denaturation of proteins.</p> Signup and view all the answers

<p>Amino acids in a secondary structure are arranged in regular, recurring patterns such as coiling or folding.</p> Signup and view all the answers

<p>Heat shock proteins are produced in larger quantities during heat exposure to assist in proper protein folding and mitigate damage.</p> Signup and view all the answers

<p>Denaturation disrupts the protein's structure, leading to loss of function due to unfolding or alteration of the secondary and tertiary structures.</p> Signup and view all the answers

<p>The primary structure dictates the sequence of amino acids, which in turn influences the formation of secondary and tertiary structures.</p> Signup and view all the answers

<p>α-helix and β-pleated sheets can coexist in the same protein, contributing to its overall stability and function.</p> Signup and view all the answers

<p>Glycoproteins are proteins that covalently bind carbohydrate units to the polypeptide backbone, playing vital roles in cell signaling, attachment, and immune regulation.</p> Signup and view all the answers

<p>Fibrous proteins have elongated strand-like structures and primarily primary and secondary structures, while globular proteins are compact, spherical, and include primary, secondary, tertiary, and quaternary structures.</p> Signup and view all the answers

<p>Keratins provide mechanical protection, support, and shape, forming integral parts of nails, hair, and the outer skin layer.</p> Signup and view all the answers

<p>Lipoproteins facilitate the absorption and transport of lipids in the bloodstream, combining proteins with lipids for this purpose.</p> Signup and view all the answers

<p>Myoglobin serves as an oxygen carrier in muscle cells, while hemoglobin transfers oxygen from the lungs to tissues throughout the body.</p> Signup and view all the answers

<p>Fibrous proteins are resistant to digestion primarily due to their structured organization and the presence of disulfide bonds, which stabilize their long strands.</p> Signup and view all the answers

<p>Globular proteins, with their complex and folded structures, provide active sites essential for catalytic activity, distinguishing them as enzymes.</p> Signup and view all the answers

<p>The number of disulfide bonds and other binding forces within keratin determines its flexibility, resulting in varying properties across different tissues.</p> Signup and view all the answers

<p>The classification into fibrous and globular proteins affects their biological functions, as fibrous proteins provide structural support while globular proteins are often involved in metabolic processes.</p> Signup and view all the answers

<p>Plasma albumins are important transport proteins in the blood, responsible for maintaining osmotic pressure and transporting various substances.</p> Signup and view all the answers