Exam 3 Part 5

Question 1

switches

Answer 1

used in most signaling from the surface

can switch on with the addition or removal of phosphate or GTP

Question 2

protein kinase

Answer 2

phosphorylates ATP to ADP

Question 3

protein phosphatase

Answer 3

removes phosphate from something like a switch

Question 4

G-proteins

Answer 4

ex. Heterotrimeric GTPase

big, 3 unit protein involved in signalling

Question 5

Heterotrimeric GTPase

Answer 5

has alpha, beta, and gamma subunits
Signal binding to a 7 transmembrane domain receptor causes the complex to bind to the receptor, and alpha subunit disassociates

Question 6

Second messengers

Answer 6

amplify a signal

ex. cyclic AMP, adenylyl, inositol triphosphate, DAG, Ca++

Question 7

Second messengers

Answer 7

amplify a signal

ex. cyclic AMP

Question 8

investingating singaling

Answer 8

cell functional data (migration, aggregation, cell death, cell growth, etc)

Question 9

western blot

Answer 9

look for changes in protein expression in response to signaling
antibodies for signaling events
co-immunoprecipitations

Question 10

DNA arrays

Answer 10

measure gene transcriptions

Question 11

microarray

Answer 11

compares two populations of expressed genes to see what differing cell conditions does to expression
uses a disc where samples will hybridize to nucleotides in certain wells

Question 12

cell transfection

Answer 12

addition of extra-chromosomal DNA to a cell

Question 13

transient transfection

Answer 13

have genes NOT pass onto next gen

new genes do NOT become part of the genome

Question 14

stable transfection

Answer 14

genes become part of the gemone and pass to nxt gen

Question 15

stable transfection

Answer 15

genes become part of the genome and pass to nxt gen

Question 16

mutational analysis

Answer 16

can introduce a mutant gene that is always on or offf. ex. look at enzyme-linked receptors and change a binding site to something else that does not phosphorylate OR change to perpectually phosphorylated with glutamate

Question 17

glutamate

Answer 17

has a group that looks like phosphate – can be used to see what a perpetual phosphorylation does

Question 18

FRET

Answer 18

fluorescence resonance energy transfer

uses wavelengths to excite proteins to see if they are looked near each other in 3D space

Question 19

enzyme-linked receptors

Answer 19

receptor has an enzyme domain which becomes enzymatically active upon binding to a receptor
2 individual proteins move together upon binding to become active together – phosphorylate each other (autophosphorylation)
phosphates serve as docking sites for other proteins to come together

Question 20

autophosphorylation

Answer 20

2 enzymes in enzyme-linked receptors phosphorylate each other
these phosphates serve as docking sites for other proteins

Question 21

amino acids with OH group

Answer 21

serine, threonine (similar side chains), and tyrosine

Question 22

RTK

Answer 22

receptor tyrosine kinase

on enzyme-linked receptors

Question 23

small GTPases

Answer 23

individual alpha subunit that exists by itself

couple with enzyme-linked receptors

Question 24

most important aspect of cell signaling

Answer 24

there is an altered cell behavior

Question 25

matrix and signaling

Answer 25

matrix can be a signaling ligand (thus, integrins can be signal receptors)
loss of adhesion can lead to cell death
stretching of cells changes intracellular signaling
organ growth depends on matrix
stem cells rely on matrix rigidity for differentiation

Question 26

Vibrio cholerae

Answer 26

prevens the alpha subunit from shutting off, leading to high secretion of water and salt

Question 27

Bordetella pertussis

Answer 27

prevents the activation of the alpha subunit, turning off cAMP production