Master this deck with 20 terms through effective study methods.
Generated from uploaded pdf
Chemical modifications such as phosphorylation and dephosphorylation of amino acids can significantly alter protein function. Phosphorylation is typically mediated by protein kinases, while dephosphorylation is carried out by phosphatases.
Phosphorylation activates glycogen phosphorylase, which plays a crucial role in glycogen breakdown. This modification allows the enzyme to catalyze the release of glucose-1-phosphate from glycogen.
Zwitterions are molecules that have both positive and negative charges but are overall neutral. In amino acids, this occurs when the amino group is protonated and the carboxyl group is deprotonated, affecting their solubility and reactivity in different pH environments.
Myoglobin is a monomeric protein that binds oxygen in muscle tissues, while hemoglobin is a tetrameric protein found in red blood cells that transports oxygen throughout the body. This structural difference contributes to their distinct functions.
The different saturation curves are due to the cooperative binding of oxygen in hemoglobin, which allows for increased oxygen affinity as more oxygen molecules bind. In contrast, myoglobin has a hyperbolic saturation curve due to its non-cooperative binding.
Diseases such as Creutzfeldt-Jakob disease and Mad Cow disease (caused by prions) are linked to the formation of misfolded protein fibers, leading to neurodegeneration and other severe health issues.
Mutations can lead to changes in the amino acid sequence of proteins, which may alter their structure and function. For example, the Hammersmith mutation weakens heme binding in hemoglobin, while the Kansas mutation disrupts hydrogen bonds stabilizing its structure.
Chaperones are proteins that assist in the proper folding of other proteins, preventing misfolding and aggregation. They play a critical role in ensuring that proteins achieve their functional conformations.
The primary structure of a protein refers to the linear sequence of amino acids linked by peptide bonds. This sequence determines the higher levels of protein structure and its biological function.
The four levels of protein structure are primary (amino acid sequence), secondary (alpha helices and beta sheets), tertiary (three-dimensional folding), and quaternary (assembly of multiple polypeptide chains).
The ionization state of amino acids is influenced by pH. At low pH, amino acids are protonated, while at high pH, they are deprotonated. This affects their charge and interactions in biological systems.
The peptide bond has a planar geometry, which restricts rotation around the bond. This restriction influences the overall conformation of the protein and its functional properties.
Denaturation is the process by which proteins lose their native structure due to external factors such as heat, pH changes, or chemical agents, leading to a loss of biological activity.
Solvents and temperature can disrupt the non-covalent interactions that maintain protein structure, leading to denaturation. This can result in loss of function and biological activity.
ATP serves as a phosphate donor in the phosphorylation of proteins, which can activate or deactivate enzymatic activity, thereby regulating various cellular processes.
The ionic species of amino acids, determined by their ionization state, affect their solubility, reactivity, and interactions with other molecules in solution, which is crucial for protein folding and function.
The primary structure dictates the folding and interactions that lead to secondary, tertiary, and quaternary structures, ultimately determining the protein's function and stability.
Protein misfolding can lead to loss of function, aggregation, and diseases such as Alzheimer's and Parkinson's, highlighting the importance of proper protein folding for cellular health.
Mutations such as SE6βV can lead to polymerization of hemoglobin, causing conditions like sickle cell anemia, where the altered hemoglobin distorts red blood cells and impairs oxygen transport.
The structure of a protein is intrinsically linked to its function; any alteration in structure can lead to changes in activity, emphasizing the importance of proper folding and stability.