intracellular

Examples of intracellular in the following topics:

• Types of Receptors

  • Receptors, either intracellular or cell-surface, bind to specific ligands, which activate numerous cellular processes.
  • Enzyme-linked receptors are cell-surface receptors with intracellular domains that are associated with an enzyme.
  • In some cases, the intracellular domain of the receptor itself is an enzyme or the enzyme-linked receptor has an intracellular domain that interacts directly with an enzyme.
  • Hydrophobic signaling molecules typically diffuse across the plasma membrane and interact with intracellular receptors in the cytoplasm.
  • Many intracellular receptors are transcription factors that interact with DNA in the nucleus and regulate gene expression.

• Fluid Compartments

  • The major body fluid compartments include: intracellular fluid and extracellular fluid (plasma, interstitial fluid, and trancellular fluid).
  • The intracellular fluid of the cytosol or intracellular fluid (or cytoplasmic matrix) is the liquid found inside cells.

• Intracellular Hormone Receptors

  • They then adhere to intracellular receptors residing in the cytoplasm or in the nucleus.
  • An intracellular nuclear receptor (NR) is located in the cytoplasm bound to a heat shock protein (HSP).
  • Describe how hormones alter cellular activity by binding to intracellular receptors

• Body Fluid Composition

  • The cytosol or intracellular fluid consists mostly of water, dissolved ions , small molecules, and large water-soluble molecules (such as proteins).
  • The pH of the intracellular fluid is 7.4. while human cytosolic pH ranges between 7.0 - 7.4, and is usually higher if a cell is growing
  • The concentrations of the other ions in cytosol or intracellular fluid are quite different from those in extracellular fluid.
  • Describe the composition of intracellular and extracellular fluid in the body

• Binding Initiates a Signaling Pathway

  • Ligand binding to cell-surface receptors activates the receptor's intracellular components setting off a signaling pathway or cascade.
  • This type of receptor spans the plasma membrane and performs signal transduction in which an extracellular signal is converted into an intracellular signal.
  • Enzyme-linked receptors are cell-surface receptors with intracellular domains that are associated with an enzyme.
  • In some cases, the intracellular domain of the receptor itself is an enzyme.
  • Other enzyme-linked receptors have a small intracellular domain that interacts directly with an enzyme.

• Genome Reduction

  • Many genes have been transferred to the host nucleus, while others have simply been lost and their function replaced by host processes.Other bacteria have become endosymbionts or obligate intracellular pathogens and have experienced extensive genome reduction as a result.
  • In fact, as much as 90% of the genetic material can be lost when a species makes the evolutionary transition from a free-living to obligate intracellular lifestyle.
  • It is important to note, however, that some obligate intracellular species have positive fitness effects on their hosts.
  • This model illustrates four general features of reduced genomes and obligate intracellular species: ‘genome streamlining' resulting from relaxed selection on genes that are superfluous in the intracellular environment; a bias towards deletions (rather than insertions), which heavily affects genes that have been disrupted by accumulation of mutations (pseudogenes); very little or no capability for acquiring new DNA; and considerable reduction of effective population size in endosymbiotic populations, particularly in species that rely on vertical transmission.

• Chlamydiae

  • Chlamydiae are a bacterial phylum and class whose members are obligate intracellular pathogens.
  • Chlamydiae are a bacterial phylum and class whose members are obligate intracellular pathogens.
  • Chlamydiae replicate inside the host cells and are termed intracellular.
  • Most intracellular chlamydiae are located in an inclusion body or vacuole .

• Invertebrate Digestive Systems

  • Invertebrates can be classified as those that use intracellular digestion and those with extracellular digestion.
  • The simplest example of digestion intracellular digestion, which takes place in a gastrovascular cavity with only one opening.
  • The food particles are engulfed by the cells lining the gastrovascular cavity and the molecular are broken down within the cytoplasm of the cells (intracellular).
  • Their food is broken down in their digestive tract (extracellular digestion), rather than inside their individual cells (intracellular digestion).

• Potassium Balance Regulation

  • Potassium is predominantly an intracellular ion .

• Carboxysomes

  • Carboxysomes are intracellular structures that contain enzymes involved in carbon fixation and found in many autotrophic bacteria.
  • Carboxysomes are intracellular structures found in many autotrophic bacteria, including Cyanobacteria, Knallgasbacteria, Nitroso- and Nitrobacteria.