Cell Signaling Process Quiz

The process of communication between cells using chemical signals.

Chemical messengers used by cells to communicate.

Signaling molecules yeast cells use to identify mates.

A way bacteria coordinate behavior based on cell number.

Two types of yeast cells ('a' and 'α') that identify and fuse with the opposite type.

Structure formed by bacteria to protect spores during scarcity.

A protein that responds to a specific signal molecule.

Bacteria that use quorum sensing for spore formation.

A protein that binds to a signaling molecule and initiates a cellular response.

The second stage of cell signaling, where the receptor protein's shape change initiates a series of reactions that convert the signal.

The final stage of cell signaling, where the signal triggers a specific action in the target cell.

A cell that has receptors specific to a signaling molecule.

A type of transmembrane receptor protein involved in signal transduction.

A protein found on the surface of a cell membrane that binds to signaling molecules and triggers intracellular responses.

A type of transmembrane receptor that opens a gate to allow ions to pass through when a signaling molecule (ligand) binds to it.

When a signaling molecule binds, the receptor changes shape, opening the gate for specific ions to enter the cell, altering the cell's internal ion concentration. This change can directly affect the cell's activity.

Once the ligand detaches from the receptor, the gate closes, preventing further ion flow into the cell.

Neurotransmitters released at a synapse bind to ligand-gated ion channels on the receiving nerve cell, triggering an electrical signal.

A receptor protein located within the cytoplasm or nucleus of a cell that binds to signaling molecules that can cross the cell membrane.

Steroid hormones, thyroid hormones, and nitric oxide (NO) are examples of signaling molecules that can pass through the cell membrane.

Once inside the cell, the signaling molecule binds to the receptor, forming a complex that triggers a response, often turning genes on or off.

Only cells with the specific receptor for a given signaling molecule will respond to it, ensuring targeted action.

The process of converting a signal from outside the cell to a specific response inside the cell.

Proteins that pass a signal along a signaling pathway. They are often activated by adding or removing a phosphate group.

A mechanism where a small signal is amplified by multiple steps in a signaling pathway, resulting in a stronger response.

A lipid-based signaling molecule that can pass through the plasma membrane and bind to receptors inside the cell.

A protein that binds to DNA and regulates gene expression by controlling the transcription of genes into mRNA.

Steroid hormones are lipid-soluble, meaning they can pass directly through the phospholipid bilayer of the plasma membrane and enter the cell.

The complex binds to specific DNA sequences called promoters, which are located near the start of genes. This binding promotes the recruitment of RNA polymerase, which then initiates transcription of the gene into mRNA.

The process of adding a phosphate group to a protein, often changing its shape and activity.

An enzyme that transfers a phosphate group from ATP to a protein, often activating it.

Serine and threonine amino acids.

A series of protein kinases where one activates another, with each activating a different protein.

The process of removing a phosphate group from a protein, often deactivating it.

An enzyme that removes phosphate groups from proteins, often deactivating them.

It becomes inactive and available to be reused.

It amplifies a signal, allowing a small initial signal to have a large effect on the cell.

Cellular responses to signals that involve changes inside the nucleus, often affecting gene expression.

Cellular responses to signals that occur outside the nucleus, directly affecting proteins and processes in the cytoplasm.

Key steps in a signaling pathway where the response can be adjusted or regulated.

Proteins that organize and bring together signaling molecules, increasing signaling efficiency.

The process of shutting down a signal after its job is done.

Signal termination ensures appropriate cellular responses and prevents uncontrolled reactions, contributing to cell homeostasis.

Different cells respond uniquely to the same signal due to variations in their protein composition. This allows for tailored responses based on cell type and function.

Cells have different sets of proteins, including receptors, relay proteins, and effector proteins, which determine their unique responses to a signal.

An enzyme activated during signaling that breaks down glycogen into glucose 1-phosphate, a precursor for energy production.

This is unanswerable without the details presented in Figure 11.16. The number of released glucose molecules is amplified through a cascade of reactions.

A single signaling molecule can trigger multiple relay proteins and second messengers, leading to a complex network of responses. Different pathways can converge to regulate a single response.

Large relay proteins that organize and bring together multiple proteins involved in a signaling pathway, enhancing the speed and accuracy of signal transfer.

Interaction between different signaling pathways, allowing for a coordinated and integrated cellular response.

Cells utilize a limited number of proteins in different combinations to participate in multiple signaling pathways, reducing the need for a large number of unique proteins.

Programmed cell death, a controlled process where cells self-destruct in a controlled manner.

Two key proteins essential for apoptosis in C. elegans, they are inactive until a death signal is received.

A regulatory protein that inhibits Ced-3 and Ced-4, preventing apoptosis.

A sequence of events initiated by a death signal, leading to activation of caspases and cell death.

Proteases and nucleases that fragment cell components during apoptosis.

The main caspase in C. elegans, responsible for carrying out the cell death program.

More complex than in C. elegans, involving multiple caspases and various pathways depending on cell type and signal.

The basic process of apoptosis is similar in C. elegans and mammals, but mammals have more intricate pathways.

Calcium ions (Ca²⁺) act as a crucial intracellular messenger. Their concentration changes in response to signals, triggering various cellular responses.

Small molecules that relay signals within a cell, amplifying and spreading the signal from the receptor to target proteins.

Inositol trisphosphate (IP₃) is a second messenger that triggers the release of calcium ions from the endoplasmic reticulum (ER).

Diacylglycerol (DAG) is a second messenger involved in activating protein kinase C, another important signaling pathway.

IP₃ binds to IP₃-gated calcium channels on the ER membrane, opening the channels and allowing calcium ions to flow out into the cytosol.

1. Signaling molecule binds to the receptor. 2. Receptor activates phospholipase C. 3. Phospholipase C cleaves PIP₂ into DAG and IP₃. 4. IP₃ diffuses and binds to ER channels. 5. Calcium ions flow out of the ER. 6. Calcium activates proteins, triggering responses.

Signal transduction involves converting a signal from outside the cell into a cellular response. In calcium signaling, a signal from a receptor is amplified and relayed within the cell.

Receptor tyrosine kinases can also activate this pathway, demonstrating its versatility in different signaling situations.