Chapter 9

Question 1

In what ways are ligand-receptor complexes similar to enzyme-substrate complex?

Question 2

What are the four types of cell signaling?

Question 3

Define signal transduction pathway

Question 4

What are the three types of membrane receptors?

Question 5

What is a G protein?

Question 6

What is a second messenger?

Question 7

Why are lipid hormones good for relaying signals across long distances?

Question 8

Why does estrogen have a different effect in mammary vs uterine cells?

Question 9

Describe the structure and function of RTKs

Question 10

Ligand

Answer 10

signaling molecule that binds to a specific receptor protein

Question 11

Receptor protein

Question 12

Protein kinase

Answer 12

class of enzyme that adds phosphate groups from ATP to proteins

Question 13

Phosphate is added to a free —OH on one of the three amino acids:

Answer 13

1. Serine
2. Threonine
3. Tyrosine

Question 14

Phosphatases

Answer 14

class of enzyme that removes phosphate groups from a protein

Question 15

Intracellular receptors bind to _______ ligands

Answer 15

hydrophobic

Question 16

__________ receptors bind to hydrophobic ligands

Answer 16

Intracellular

Question 17

Cell-surface/membrane receptors bind to ________ ligands

Answer 17

hydrophilic

Question 18

____________ receptors bind to hydrophilic ligands

Answer 18

Cell-surface/membrane

Question 19

G protein is a protein that binds _____________.

Answer 19

guanosine triphosphate (GTP)

Question 20

Steroid hormone receptors are an example of what type of receptor?

Answer 20

Intracellular receptor

Question 21

What is the primary function of steroid hormone receptors?

Answer 21

regulation of gene expression

Question 22

What are the three functional domains of steroid receptors?

Answer 22

1. Hormone-binding domain
2. DNA-binding domain
3. Domain interacts with coactivators to affect level of gene transcription

Question 23

Coactivator

Question 24

T or F: Ligands can bind to any receptor

Answer 24

F: Specific ligands can only bind its complementary receptor

Question 25

What is an example of direct contact?

Answer 25

Gap junctions

Question 26

Example of paracrine signaling

Answer 26

Signaling between immune cells

Question 27

What is an example of endocrine signaling

Answer 27

Hormones

Question 28

What is an example of synaptic signaling?

Answer 28

Neurotransmitter

Question 29

__________ is a primary mechanism for control of proteins

Answer 29

Phosphorylation (and dephosphorylation)

Question 30

What is the structure of RTKs?

Answer 30

Single transmembrane domain Extracellular ligand-binding domain Intracellular kinase domain

Question 31

What molecules can be used as signals in cell signaling?

Answer 31

Peptides, large proteins, amino acids, nucleotides, steroids or other lipids, dissolved gases or ions

Question 32

Which types of cell signaling are important in early development?

Answer 32

Direct contact and paracrine signaling

Question 33

Paracrine signaling

Answer 33

Signal releases from a cell has an effect on neighboring cells

Question 34

Endocrine signaling

Answer 34

Signal molecule released from a cell travels through circulatory system to affect other cells throughout body

Question 35

T or F: only animals use endocrine signaling.

Answer 35

F: both animals and plants use this endocrine signaling

Question 36

______ signaling is often signaled by one cell type to a different cell type

Answer 36

Endocrine

Question 37

Synaptic signaling

Answer 37

Nerve cells release the signal, which binds to receptors on nearby cells

Question 38

What makes signal transduction pathways complex?

Answer 38

The same pathway can be activated but different receptors or the same signal can activate different cell types/responses

Question 39

How does a coactivator affect mammary tissue?

Answer 39

When coactivator is lacking, gene expression is reduced

Question 40

How does a coactivator affect uterine tissue?

Answer 40

When coactivator is present, gene expression is turned on

Question 41

Describe the process of G protein coupled receptors

Answer 41

Ligand binds to G protein coupled receptor —> activation of receptor —> activates G protein —> activates enzyme

Question 42

Dimerization

Answer 42

RTKs are brought closer together

Question 43

Autophosphorylation

Answer 43

RTKs phosphorylate each other

Question 44

Insulin

Answer 44

Hormone that helps maintain a constant blood glucose level

Question 45

How does insulin lower blood glucose level?

Answer 45

Insulin response protein binds to RTK then binds to other proteins which activates glycogen synthase. This enzyme converts glucose to glycogen