Signals: Key Models, Cells &
Organisms
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Guidelines and tips
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community
Ask the community for help and clear up your study doubts
University Rankings
Discover the best universities in your country according to Docsity users
Free resources
Our save-the-student-ebooks!
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
An overview of signal transduction in cells. It explains how cells communicate with each other and sense their environment using different methods. The document also covers the signal cascade, which is a chain of events that relays information from the site of reception to the point of action. It also discusses the role of different molecules and receptors in signal transduction and how they can turn on or off proteins. The document concludes by highlighting the importance of calcium as an intercellular messenger.
Typology: Study notes
2021/2022
1 / 19
This page cannot be seen from the preview
Don't miss anything!
Related documents
Partial preview of the text
Download Signal Transduction in Cells and more Study notes Biology in PDF only on Docsity!
Signals: Key Models, Cells &
Organisms
SIGNAL TRANSDUCTION
- Cells can exist as single celled organisms or
be part of a multi-cellular organism
- How do they know what is happening around
them?
- Cells do not have ‘eyes’, ‘noses’, or ‘ears’
SIGNAL TRANSDUCTION
Cells communicate with others and have mechanisms to sense their environments using a variety of methods as we will uncover - whichever method is used it involves a very important principle called
Cell Signaling types
• Endocrine - hormones, long distance
• Paracrine - local vicinity
• Neuronal - very short distances
• Contact-dependent - physical contact
• Autocrine - act on self
16_03_signal_various.jpg
16_06_extracellular_sig.jpg
Cells generally respond to a combination of signals. The same cell may have different outcomes to various signal combinations
Cells that DO NOT RECEIVE The default pathway= SIGNALS DIE
How do these signals work
At which level?
Where?
How many?
- Each cell responds to a limited set of
signals - why?
- These signals change the activity of
internal cellular proteins which chances the behavior of the cell
- These signals follow a chain of events
known as the signal cascade
- A system of relaying information from the
site of reception to the point of action
- Normally the signal is amplified too - a
small input is quickly converted to a large
response
16_08_cascades.jpg
General Overview 2
16_12_cortisol.jpg
A simple example of how a steroid works. -The signal can enter the cell through the membrane and bind to its target protein. -This is now able to enter through the nuclear pore and control transcription directly of certain target genes
Ion-channel linked receptors
• All nerve impulses are generated via
ion-channel linked receptors
- The release of neurotransmitter causes the
ion-channel on the target neuron to allow
the passage of ions (which?) into the cell.
This action is propagated through the
nerve cell along its axon.
16_23_slowly_rapidly.jpg
Some cellular responses are quick, whilst others are slow.
16_26_Fertilization.jpg
Calcium has a very important role to play as an intercellular messenger. As we know the concentration of calcium is extremely low in the cytoplasm of a typical cell, compared to the outside and to that of the ER.
In this example fertilization results in the wave of receptors opening up to permit the influx of calcium into the cell. This results in a change in the cell surface which both initiates cell division and prevents other sperm from entering the cell.