Exam 4 extra

Question 1

What are the 3 stages of signal transduction?

Answer 1

1. reception
2. transduction
3. response

Question 2

Paracrine vs. endocrine signaling?

Answer 2

endocrine signaling transmits long distance signals, while paracrine signaling is more localized signaling

Question 3

What is contact-dependent signaling?

Answer 3

signal molecules are bound to the membrane of the signal cell
-the receptor is in the membrane of a neighboring cell
-important for developmentapmpatterning

Question 4

What is necessary for a cell to respond to a signal

Answer 4

a cell can only respond to a signal that it has a receptor for

Question 5

what determines why the same signal/receptor complex interaction can have very different responses?

Answer 5

this is determined by which proteins are being triggered by the relay molecules

Question 6

Is a single signal enough to shape the behavior of a cell?

Answer 6

most of the time a single signal is not enough, and requires in the input of several cells

Question 7

What are 4 different ways intracellular relay signaling molecules work?

Answer 7

1. each molecule can relay the signal forward to the next signaling molecule in a linear fashion
2. can amplify the received signal
3. can detect and integrate multiple signals to relay a single signal forward
4. can distribute the signal to 1 or more effector proteins that aid in the final response

Question 8

What are the two main classes of molecular switches?

Answer 8

1. add or remove phosphates
2. GTP-binding proteins

Question 9

GEF/GAP/GTPase Rules

Answer 9

GEF –> GTPase
GAP –I GTPase
-GEFs/GAPs will always be the step BEFORE a GTPase

Question 10

What are two different examples of how cells react at different rates?

Answer 10

1. responses that occur in the cytosol (ex. release of vesicles, phosphorylation of enzymes) take seconds to minutes
2. responses that require changes in gene expression (ex. growth, division, differentiation) can take up to hours to cause changes