Hydrophobic Hormones and Intracellular Signaling

A molecule that binds to a specific receptor on a cell, initiating a signaling cascade.

A molecule that relays a signal from a first messenger to intracellular targets.

A protein that binds to a specific hormone or ligand, initiating a signal transduction pathway.

A process by which a cell responds to a signal from a hormone or other ligand.

The process by which a hormone or other ligand alters gene expression.

Chemical messengers released by endocrine glands that influence gene expression and protein activity, coordinating various bodily functions.

A communication system that uses hormones to regulate slower, long-lasting processes like growth, reproduction, and metabolism.

A communication system using electrical impulses to transmit rapid responses in the body.

A type of cell signaling where the hormone acts on a distant target.

A type of cell signaling where the hormone acts on neighboring cells.

A type of cell signaling where the hormone acts on the same cell that released it.

The concentration of hormones required to elicit a response is extremely low, ranging from 10^-9 to 10^-15 M.

Cells have specific receptors that bind to particular hormones, ensuring only target cells respond.

Mechanisms that regulate the production of hormones, often involving the product feeding back to control its own synthesis.

A type of feedback mechanism where the product of a process inhibits its own further production, maintaining a stable level.

A type of feedback mechanism where the product of a process amplifies its own production, leading to a snowball effect.

Hormones like estrogen and testosterone that are lipid-soluble and can pass through cell membranes.

Hormones like adrenaline or insulin that are water-soluble and can't easily cross cell membranes.

A protein complex inside cells that binds to steroid hormones, triggering gene transcription.

A series of molecular events triggered by hydrophilic hormones, amplifying the signal and leading to a cellular response.

A type of receptor that sits on the cell membrane and binds to hydrophilic hormones, initiating a signal transduction pathway.

A protein that relays a signal from an activated receptor to another protein, typically an enzyme, in a signal transduction pathway.

An enzyme that converts ATP into cAMP, a second messenger that amplifies the signal within the cell.

A second messenger molecule that relays the signal from an activated G-protein to other intracellular targets, such as protein kinase A.

An enzyme that is activated by cAMP, which phosphorylates other proteins, leading to changes in gene expression and cell function.

A protein that binds to a specific hormone, typically a steroid hormone, and then translocates to the nucleus to regulate gene expression.

A type of intracellular receptor that binds to steroid hormones and then interacts with specific DNA sequences to regulate gene expression.

A peptide hormone that acts on the kidneys to reduce extracellular fluid (ECF) volume by increasing sodium excretion.

The process by which a hormone binds to its receptor and initiates a chain of events that ultimately leads to a specific cellular response.

A type of receptor that has intrinsic enzymatic activity, specifically protein kinase activity. When a hormone binds, it activates the kinase domain, leading to phosphorylation of downstream targets.

The phosphorylation of tyrosine residues on a protein, often triggered by a hormone-receptor interaction.

A protein that acts as an intermediary in insulin signaling pathways. It binds to the phosphorylated insulin receptor and gets phosphorylated itself, amplifying the signal.

A common laboratory technique used to detect and quantify the presence of specific antigens or antibodies in a sample.

A type of ELISA that uses two antibodies to capture and detect the target molecule. It offers high sensitivity and specificity.

An enzyme-linked immunosorbent assay (ELISA) is a common laboratory technique used to detect and quantify specific antigens in biological samples, such as blood, serum, or urine. It relies on the specific binding of an antibody to its target antigen.

A standard curve is a graph that relates the signal intensity of different concentrations of a known standard antigen to the corresponding concentrations. This graph is used to determine the unknown antigen concentration in the patient sample by comparing its signal to the standard curve

The limit of detection (LoD) is the lowest concentration of an analyte which can be reliably detected by an analytical method. In ELISA, it signifies the lowest detectable concentration based on the assay's sensitivity.

The principle behind ELISA is the specific interaction between antibodies (Ab) and antigens. The antibody is linked to an enzyme that generates a signal when it encounters its substrate. This signal is directly proportional to the amount of antigen present in the sample.

A competitive ELISA utilizes a fixed amount of antibody, and the signal strength is inversely proportional to the concentration of target antigen in the sample. This is because more antigen in the sample means less antibody is free to bind to the well, leading to a lower signal.

Qualitative ELISA is used to determine the presence or absence of an antigen but does not measure its concentration. It provides a yes/no answer, like a pregnancy test or HIV test.

Quantitative ELISA measures the concentration of a specific antigen in a sample. Its results are expressed as units of concentration, often using a standard curve to determine the values.

The optical density (O.D.) is a measure of how much light is absorbed by a solution. In ELISA, a higher O.D. value typically indicates a higher concentration of the analyte in the sample.