Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PHYL2066 > Intercellular Communication > Flashcards

Intercellular Communication Flashcards

1
Q

Forms of DIRECT intercellular communication

A
  1. Gap Junctions
  2. Transient direct linkup of surface markers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are Gap Junctions

A

Minute tunnels that bridge the cytoplasm of neighbouring cells in some types of tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Function of gap junctions

A

Ions and small molecules are directly exchanged between closely associated interacting cells without entering the ECF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the types of extracellular chemical messengers?

A
  1. Paracrines
  2. Neurotransmitters
  3. Hormones
  4. Neurohormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are Paracrines?

A
  • Local messengers whose effect is on its immediate neighbouring cells (short distances)
  • Distributed by simple diffusion in the interstitial fluid
  • Do not gain entry to the blood as they are inactivated by existing enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are Neurotransmitters?

A
  • Short range chemical messengers released in response to action potentials
  • Diffuse from site of release across synaptic cleft to act locally on a target cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are Hormones?

A
  • Long-range chemical messengers specifically secreted into the blood by endocrine glands in response to appropriate signals
  • Blood carries messengers to other sites in the body where they exert their effects on their target cells some distance away from their site of release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are Neurohormones?

A
  • Hormones released into the blood by neurosecretory neurons
  • Respond to and can conduct electrical signals
  • Released when an action potential reaches axon terminals and is then distributed through the blood to distant target cells.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Mechanisms of signal transduction depend on?

A
  1. Messenger type
  2. Receptor type
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 2 types of messengers?

A
  • Lipid-soluble which can pass through the lipid bilayer of the target cell’s plasma membrane.
  • Water-soluble: Cannot dissolve in the plasma membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do lipid-soluble messengers initiate a response during signal transduction?

A

Initiate the desired intracellular response by changing the gene activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How to water-soluble messengers initiate response during signal transduction?

A
  • signals target cells to perform a certain response by binding with receptors specific for that given messenger on the outer surface of the plasma membrane.
  • Binding triggers a sequence of intracellular events that controls a particular cellular activity.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Explain what happens when a lipophilic hormone binds to the intracellular receptors

A
  1. Lipophilic hormone diffuses through the plasma membrane of the target cell and binds with specific receptor in the cell either in the cytoplasm or nucleus
  2. Hormone binds to the intracellular receptor
  3. Hormone binds with DNA’s hormone response element
  4. Binding activates genes that contain a code for protein synthesis
  5. Code of activated gene transcribed into mRNA
  6. mRNA leaves the nucleus and enters the cytoplasm
  7. mRNA binds to ribosomes to assemble and synthesise new proteins
  8. Protein released from ribosome
  9. New protein brings about desired response.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the types of receptors?

A
  1. Chemically-gated
  2. Receptor-enzyme complex
  3. G-Protein coupled receptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do chemically-gated receptor channels work?

A
  • Open/close specific chemically gated receptor channels to regulate movement of particular ions across the membrane.
  • Receptor itself serves as an ion channel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are examples of chemically-gated receptor channels?

A
  • EPSP
  • IPSP
  • Presynaptic-Postsynaptic
17
Q

How does a receptor-enzyme complex work?

A
  • On binding to a surface membrane receptor, extracellular messenger relays its message inside the cell by activating intracellular protein kinase
  • Phosphorylation causes protein to alter their shape and function
  • The protein kinase act in a cascade to pass along the signal to the final designated proteins.
18
Q

Explain the G protein-coupled receptor binding

A
  1. Binding of the first messenger to the receptor activates the G protein
  2. On activation, the G protein shuttles along the membrane to alter the activity of an effector protein
  3. Effector protein then leads to increased concentration of second messengers
  4. Second messenger relays the order through a cascade of chemical reactions inside the cell that causes a change in shape/function of the designated protein
  5. When the designated protein is altered, a cellular response occurs.

PHYL2066 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions