Cell Communication
This vocabulary term describes long distance cell signaling.
What is endocrine signaling
The messenger molecule
ligand
Triple points
Cellular responses are often __________ by ___________ cascades which strengthen the power of the initial signal by transducing and activating many relay molecules _______ the target cell.
amplified
phosphorylation
within/inside
Because these specific hormone molecules are non-polar/hydrophobic, their receptors are located inside the cytoplasm or nucleus rather than on the cell membrane.
What are steroid (or lipid-soluble) hormones?
The tiny gap between the axon terminal of a presynaptic neuron and the dendrite of a postsynaptic neuron is called the...
What is the synapse?
Antigen-presenting cells (APCs) like macrophages or dendritic cells physically bind via MHC molecules to T-cell receptors (TCR).
What is juxtacrine signaling?
What type of feedback increases a response until a specific outcome is reached?
This vocabulary term describes cell signaling between cells that are in physical contact with each other.
What is juxtacrine signaling
The final result of a signal transduction pathway
cellular response
Describe the physical and chemical properties of a ligand that is likely to have many target cells with intracellular receptors.
small, non-polar/hydrophobic ligands can pass directly through cell's plasma membranes and bind to intracellular receptors inside the cell
This family of cell-surface receptors works by partnering with a GTP-binding protein to turn an adjacent membrane enzyme on or off.
G Protein Coupled Receptor
When an action potential reaches the axon terminal, an influx of these ions triggers the exocytosis of neurotransmitter vesicles.
What is Ca2+
Infected cells use an MHC I to signal CD8 cells to perform apoptosis. CD8 cells release these to molecules to destroy the infected cell.
What is perforin and granzymes
Many chemical poisons, toxins, and medications work by acting as this—binding to a receptor and blocking the true ligand from attaching.
What is an inhibitor (or antagonist)?
This vocabulary term describes local signaling.
What is paracrine signaling
1. Reception
2. Transduction
3. Response
Double points
1. The process of adding a phosphate group to another molecule is called __________.
2. Generally speaking, how does this process usually change the molecule that receives the phosphate group?
1. phosphorylation
2. It changes its structure, causing a change in its function.
This class of membrane receptors attaches phosphate groups to a specific amino acid (tyrosine) on target proteins once activated by a signal.
What are receptor tyrosine kinases (RTKs)?
A neurotransmitter that binds to a postsynaptic receptor and causes an influx of Na⁺ produces this type of graded potential.
What is an Excitatory Postsynaptic Potential (EPSP)
This process involves redness, warmth, swelling, and pain caused by mast cells releasing histamine.
What is the inflammatory response?
Double points and point donation
Explain why negative feedback mechanisms are more common than positive feedback mechanisms.
Negative feedback mechanisms return an organism to its desired set point, which means they return an organism to its desired homeostatic range.
Neurotransmitters released into the synapse between different neurons is which type of cell communication?
What is paracrine or synaptic signaling
Constant _______ is an essential way in which organisms maintain ________ or internal stability.
cell communication, homeostasis
Point Donation
Large relay molecules are usually _________ which must be activated during the signal transduction process, whereas _________ are usually small, water-soluble molecules like ions or __________, which is a derivative of ATP.
proteins,
second messengers
cyclic AMP
This type of membrane receptor acts as a gate that opens or closes when a specific ligand attaches, allowing or blocking the flow of specific ions like Na⁺ or Ca²⁺.
What is a ligand-gated ion channel?
This protein guides the vesicles filled with neurotransmitters to the cell membrane and helps the vesicle fuse with the memrane for exocytosis.
What are SNARE proteins
This branch of adaptive immunity involves B cells and the production of circulating antibodies.
What is the humoral response?
What type of feedback makes a corrections when there has been a deviation from the set point?
Negative feedback
Which type of signaling usually involves hormones as the ligand?
What is endocrine signaling
What is a common result of a disruption to a signal transduction pathway?
disease
Ligands have specific _______ that only match up with specific receptors. Once a ligand binds to a receptor, the receptor will either experience a conformational change or will release another molecule that initiates the ________ transduction pathway that will eventually cause a cellular _________.
shapes/structures/conformations
intracellular
response
This rule governs why a heart muscle cell and a smooth muscle cell can receive the exact same neurotransmitter or hormone, yet react completely differently.
What is the idea that different cell types have different receptor proteins, relay molecules, and downstream target proteins?
This enzyme breaks down acetylcholine (ACh) in the synaptic cleft to terminate the signal.
What is acetylcholinesterase?
These master orchestrators of the adaptive immune response release cytokines to activate both B cells and cytotoxic T cells.
What are helper T cells?
In Type 2 diabetes, insulin is released into the blood, but target cells fail to respond properly because of a defect in these structures or internal pathways.
What are insulin receptors (or signal transduction pathways)?