Untitled Quiz

The precise regulation of calcium concentration within cells and the body.

A positively charged ion crucial for many biological processes.

Proteins that facilitate calcium movement into and out of cells.

Calcium concentration outside cells.

Calcium concentration inside cells.

Proteins that bind calcium to prevent its buildup and maintain proper concentrations.

Pumps that use energy from ATP to actively transport calcium across membranes.

Plasma membrane Calcium ATPase

Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase

Protein channels that allow calcium to passively pass through cell membranes.

IP3R are tetramers of 4 transmembrane spanning helices that play a role in intracellular calcium signaling.

Store-operated calcium entry (SOCE) is a process that allows calcium to enter cells when intracellular calcium stores are depleted. It relies on STIM1 and Orai proteins.

STIM1 is a single-pass transmembrane protein that senses changes in ER luminal Ca2+ levels, signaling to increase calcium entry.

Orai proteins are plasma membrane proteins that are activated by STIM1, facilitating calcium entry into the cell.

Intracellular calcium levels are tightly regulated and are crucial for various cellular functions. They are mainly bound by calcium-binding proteins in the cytoplasm and cellular organelles (e.g. ER/SR).

Maintaining stable levels of calcium within the cell

Proteins that move calcium ions across membranes using ATP energy, maintaining proper calcium concentration.

Channels that open in response to changes in membrane potential, allowing calcium to enter cells.

Plasma membrane Ca2+-ATPase, a protein that pumps calcium ions out of the cell, using energy from ATP hydrolysis.

A genetic change in STIM1 leading to increased SOCE activity.

Sarcoplasmic/Endoplasmic Reticulum Calcium-ATPase; pumps calcium ions into the sarcoplasmic reticulum (SR) for storage. Uses ATP.

Clustering of STIM1 proteins when stimulated by calcium depletion in the ER.

Sodium-Calcium Exchanger. A protein that moves 3 sodium ions into the cell in exchange for 1 calcium ion out of the cell.

Voltage-gated calcium channels, proteins that open and close in response to changes in membrane potential, allowing calcium to flow into the cell.

The largest subunit of voltage-gated calcium channels, containing the ion selectivity filter and voltage sensor.

Inositol 1,4,5-trisphosphate, a second messenger that triggers calcium release from intracellular stores, like the ER.

A type of voltage-gated calcium channel, found in various tissues like muscle and nerve, responsible for prolonged calcium influx.

Specific regions in proteins like NCX, that bind to calcium ions, regulating activity.

The process of maintaining a stable level of calcium in cells.

A metabolite of vitamin D, playing a vital role in calcium regulation.

A protein that regulates the activity of SERCA, affecting calcium uptake into the sarcoplasmic reticulum.

Proteins that pump calcium ions out of the cell.

Proteins exchanging sodium and calcium ions across membranes.

Substances within cells that bind to calcium, preventing it from rising to excess.

Protein channels that allow calcium entry into cells in response to electrical signals.

Signaling molecules produced by GPCRs, triggering calcium release.

Proteins involved in calcium flow through cell membranes.

Release of neurotransmitters via calcium influx.

Diverse cellular functions driven by calcium changes.

A fundamental process where calcium plays a central role, initiating the mechanical response in muscles.