Cell Communication (Signalling) and Cell Division Flashcards
What is a signalling cell?
The original cell that sends a signal.
What is a signalling molecule?
The substance/message sent from one cell to another to elicit a response. A signalling molecule may be a hormone, neurotransmitter or any other kind of protein secreted by a cell.
What is a target cell?
The cell that receives a message (signalling molecule) from the signalling cell.
What is a receptor?
A chemical structure located on the outside of the cell that receives the message/substance (signalling molecule).
Receptors can be thought of as a lock and signalling molecules are the key: they are specific to each other and therefore only a target cell with the right receptor will respond to the signalling molecule.
What are the three types of cell signalling?
N______ signalling
P______ signalling
E______ signalling
Neural signalling
Paracrine signalling
Endocrine signalling
In neural signalling, a neuron (nervous system cell) releases proteins known as n___________ (signalling molecules), which then attach to another neuron or muscle cell (target cell) to communicate a message.
A neural signal acts d__________ on a target cell (the target cell is far away from the signalling cell).
neurotransmitters
downstream
In paracrine signalling, a neuron (signalling cell) secretes protein molecules to another neuron or muscle cell (target cell) that is located in ________ proximity.
Paracrine signalling happens inside tissues.
close proximity
In endocrine signalling, an endocrine cell (thyroid, hypothalamus, pituitary, pancreas, gonads) releases hormones that enter the c________ s______ and travel via the b_______.
Target cells are located far away from the signalling endocrine cell.
circulatory system, bloodstream
Name the five (5) events in signaling.
- E_________ signal
- R_______
- T_______ C_______
- T______
- I______ r_______
- Extracellular signal
- Receptor
- Transduction Cascade
- Targets
- Intracellular response
Name 3 types of signalling molecules.
a. neurotransmitters (secreted from neuron, act on downstream target i.e. muscle cell)
b. protein molecules (secreted from a signalling cell, act locally i.e. within a tissue)
c. hormones (secreted from endocrine cell, delivered to target cell through circulation)
What is a receptor?
Chemical structure on the outside of the cell that is specific to a signalling molecule.
Only certain receptors and molecules match each other.
What does the Transduction cascade do?
amplification of signal and an intracellular response.
Target proteins are activated as a result of the transduction cascade. Once activated, they may respond in one of the following ways:
- G____ e_____ r______ (production of a protein)
- M________ a_______ (change a reaction in the cell)
- C_______ m_______ and s______ a______
- Gene expression regulation (production of a protein)
- Metabolism alteration (change a reaction in the cell)
- Central motility and shape alteration
Intracellular responses are the final result of cell signalling that occur once target proteins have been activated.
There are 4 types of intracellular responses:
- S______
- D______
- D_______
- G_____ and d______ (cell cycle)
Survive
Differentiate
Die
Grow and divide (cell cycle)
Once a cell recieves a message the following occur, explain what happens in each: Survive Differentiate Die Grow and divide (cell cycle)
Survive - the cell remains the same
Differentiate - grows/changes into a mature cell or a different type of cell
Die - cell ceases to exist either by every cell is pre-programmed to die (Apoptosis) or cell becomes damaged (Necrosis)
Grow and divide (cell cycle) - cell divides to become two of the same original cell
