BIOL 2070 - LECTURE 8/9? EXAM QUESTIONS AND VERIFIED
ANSWERS LATEST UPDATE
True or False: signals can act over a long or short range
True
True or False: A cell's response to a signal is always very quick
False. It can be slow too
How do cell-surface receptors relay extracellular signals?
Intracellular signalling pathways
What are the three main classes of cell-surface receptors?
ion channel receptors, G-protein coupled receptors, and enzyme-linked receptors.
FITB: Some intracellular signalling proteins act as _______ _______
Molecular switches
What do ion-channel-coupled receptors do?
convert chemical signals into electrical ones
What is signal transduction?
The process whereby one type of signal is converted into another
A target cell has converted an extracellular signal into an intracellular signal.
What is this an example of?
Signal transduction
FITB: Hormones produced in the endocrine glands are secreted into the ______
to be distributed throughout the body
, Bloodstream
FITB: _______ signals are released by cells into the extracellular fluid
Paracrine
True or False: Paracrine signals act locally
True
How are neuronal signals transmitted?
electrically along a nerve cell axon
When an electrical signal reaches the nerve terminal, what is released?
Neurotransmitters onto adjacent target cells
In what type of signalling do cell-surface-bound signal molecules bind to a
receptor protein on an adjacent cell?
Contact-dependent signalling
What are some examples of hormones that act as signal molecules?
Cortisol, epinephrine, insulin, estradiol, testosterone, thyroxine
True or False: Acetylcholine is a signal molecule.
True
Correct this statement: Extracellular signal molecules bind only to cell-surface
receptors.
Extracellular signal molecules bind to either cell-surface receptors or to intracellular
receptors
Why are extracellular signal molecules usually unable to cross the plasma
membrane directly?
They are usually large and hydrophillic
ANSWERS LATEST UPDATE
True or False: signals can act over a long or short range
True
True or False: A cell's response to a signal is always very quick
False. It can be slow too
How do cell-surface receptors relay extracellular signals?
Intracellular signalling pathways
What are the three main classes of cell-surface receptors?
ion channel receptors, G-protein coupled receptors, and enzyme-linked receptors.
FITB: Some intracellular signalling proteins act as _______ _______
Molecular switches
What do ion-channel-coupled receptors do?
convert chemical signals into electrical ones
What is signal transduction?
The process whereby one type of signal is converted into another
A target cell has converted an extracellular signal into an intracellular signal.
What is this an example of?
Signal transduction
FITB: Hormones produced in the endocrine glands are secreted into the ______
to be distributed throughout the body
, Bloodstream
FITB: _______ signals are released by cells into the extracellular fluid
Paracrine
True or False: Paracrine signals act locally
True
How are neuronal signals transmitted?
electrically along a nerve cell axon
When an electrical signal reaches the nerve terminal, what is released?
Neurotransmitters onto adjacent target cells
In what type of signalling do cell-surface-bound signal molecules bind to a
receptor protein on an adjacent cell?
Contact-dependent signalling
What are some examples of hormones that act as signal molecules?
Cortisol, epinephrine, insulin, estradiol, testosterone, thyroxine
True or False: Acetylcholine is a signal molecule.
True
Correct this statement: Extracellular signal molecules bind only to cell-surface
receptors.
Extracellular signal molecules bind to either cell-surface receptors or to intracellular
receptors
Why are extracellular signal molecules usually unable to cross the plasma
membrane directly?
They are usually large and hydrophillic
