Which signalling method allows cells in close proximity to rapidly coordinate a response via direct cytoplasmic exchange
Direct signaling via gap junctions
A mutation in a cell receptor prevents dimerization after ligand binding. What is the response
No signal passed onto cell
Cells exposed to a new ligand show
In which scenario would autocrine signaling be the most beneficial
Early embryo cells determining fate
Blocking intercellular mediators in cardiac muscle via gap junctions will most immediately affect which process
Synchronous contraction
A hydrophobic ligand administered in a lab experiment
Internal receptor in the cytoplasm or nucleus
Given a data set showing rapid, short term local affects of signaling which type of communication
Direct signaling via gap junctions
If an ion channel-linked cell receptor loses selectivity, whatll happn
Uncontrolled ion influx or efflux
A population of cells treated in nitroglycerin display rapid relaxation of smooth tissue. What is the most likely signal molecule
Nitrous oxide
In a negative feedback cascade controlled by enzyme degradation what happens to the cells response
Signal lasts longer
Which type of data would most likely support the involvement of enzyme receptors in a disease process
Overexpression and continuous actuvation of receptor tyrosine kinases
Which type of data would most likely support the involvement of enzyme receptors in a disease process
Overexpression and continuous actuvation of receptor tyrosine kinases
In a cancer cell, which signaling defect is most likely to lead to uncontrolled then
Constitutively active enzyme linked receptor
What is the the term for the molecule that binds to a receptor
Ligand
Which type of receptor is found inside the cytoplasm and responds to hydrophobic ligands
Internal receptor
Which glands are involved in endocrine signaling
Thyroid and pituitary
What is the function of cell surface receptors
Convert extracellular signals to intracellular signals
A neurotransmitter released from a presynaptic cell binds to a receptor on a postsynaptic cell. What type of signaling is that
Direct
Compare paracrine and endocrine signaling. Which statement is true
Paracrine signaling is faster and more localized than endocrine signaling
In the graph of ATP production versus oxygen availability when the durve flattens at low oxygen what main processes does this represent
Switch from oxidative phosphorization to feementation
Wgat distinguishes G protein linked receptors from enzyme linked receptors
G protein linked activate secondary proteins
Which of the following is the correct order
Ligand/receptor- dinerization- signal cascade
A mutation causes a G protein to remain active without ligand binding.
Constant activation of downstream pathways
Why is the termination of a signal cascade important
To avoid overstimulation of cellular health
