C2.1 Chemical Signalling Flashcards
What is chemical signaling?
The process by which cells communicate with each other through chemical signals.
True or False: Chemical signaling only occurs in multicellular organisms.
False
What are the main types of chemical signals?
Hormones, neurotransmitters, and local mediators.
Fill in the blank: Hormones are produced by ______ glands.
endocrine
What is the role of neurotransmitters?
To transmit signals across synapses between neurons.
Multiple Choice: Which of the following is NOT a type of chemical signaling? A) Endocrine B) Paracrine C) Exocrine D) Autocrine
C) Exocrine
Define autocrine signaling.
A type of signaling where a cell targets itself.
What is paracrine signaling?
Signaling where a cell targets nearby cells.
True or False: Hormonal signals can have long-lasting effects.
True
What is the primary function of signaling molecules?
To elicit a specific response in target cells.
Fill in the blank: The receptor proteins are located on the ______ of the target cell.
membrane
What happens when a signaling molecule binds to its receptor?
It triggers a conformational change in the receptor, initiating a cellular response.
Multiple Choice: Which type of signaling is characterized by hormones traveling through the bloodstream? A) Autocrine B) Endocrine C) Paracrine D) Juxtacrine
B) Endocrine
Define juxtacrine signaling.
Direct signaling between adjacent cells through surface molecules.
What is a ligand?
A molecule that binds specifically to a receptor.
True or False: All receptors can respond to multiple types of signaling molecules.
False
What is signal transduction?
The process by which a cell converts an external signal into a functional response.
Fill in the blank: The ______ pathway is often involved in signal transduction.
second messenger
What role do second messengers play in signaling?
They amplify the signal within the cell and propagate the response.
Multiple Choice: Which is a common second messenger? A) ATP B) cAMP C) GTP D) NADH
B) cAMP
What is the function of protein kinases in signaling pathways?
To phosphorylate target proteins, altering their activity.
True or False: Only water-soluble hormones can pass through the cell membrane.
False
What is the significance of feedback mechanisms in chemical signaling?
They regulate the production and activity of signaling molecules to maintain homeostasis.
Fill in the blank: Negative feedback loops help to ______ the effects of a hormone.
diminish
What is the role of the hypothalamus in hormonal signaling?
To regulate the pituitary gland and coordinate the endocrine system.
Multiple Choice: Which hormone is released in response to stress? A) Insulin B) Cortisol C) Estrogen D) Thyroxine
B) Cortisol
What triggers the release of neurotransmitters?
An action potential reaching the synaptic terminal.
True or False: Chemical signaling is only involved in physiological processes.
False
What is the primary difference between endocrine and exocrine signaling?
Endocrine signaling uses the bloodstream, while exocrine signaling involves secretion to external surfaces.
Fill in the blank: ______ receptors are found inside the cell and respond to lipid-soluble hormones.
Intracellular
What is the effect of glucagon on blood glucose levels?
It increases blood glucose levels.
Multiple Choice: Which type of signaling would you associate with inflammation? A) Autocrine B) Paracrine C) Endocrine D) Juxtacrine
B) Paracrine
Define neuroendocrine signaling.
Signaling that integrates the nervous and endocrine systems through neurohormones.
True or False: Chemical signals can only be proteins.
False
What is the role of receptors in cellular response?
To bind specific signaling molecules and initiate a response.
Fill in the blank: The ______ system is responsible for the release of hormones into the bloodstream.
endocrine
What type of signaling involves a cell responding to its own signals?
Autocrine signaling.
Multiple Choice: Which hormone lowers blood sugar levels? A) Glucagon B) Insulin C) Cortisol D) Epinephrine
B) Insulin
What is a key characteristic of local mediators?
They act on nearby cells rather than being transported through the bloodstream.
True or False: All signaling pathways are linear and straightforward.
False
What is the primary purpose of chemical signaling in organisms?
To coordinate and regulate physiological processes.
Fill in the blank: Signal ______ is crucial for proper cellular communication.
amplification
What is the function of the pituitary gland in the endocrine system?
To secrete hormones that regulate other glands and bodily functions.
