Chapter 11

Question 1

• cell junctions allow signaling molecules to pass freely between adjacent cells
• cell-cell recognition via cell-surface molecules
• paragons signaling

Answer 1

Local signaling

Question 2

• uses hormones

- travel through bloodstream to reach target cells

Answer 2

Long distance signaling

Question 3

Ability of a cell to respond depends on whether it has ____ that can bind the signaling molecule

Answer 3

Receptors

Question 4

3 stages of cell signaling

Answer 4

1. Reception
2. Transduction
3. Response

Question 5

Receptor protein on surface of cell (or inside) binds the signaling molecule (ligand) and transmits the signal

Answer 5

Reception

Question 6

Binding is very specific and can cause receptor to:

Answer 6

Change shape

Question 7

3 main types of membrane receptors

Answer 7

• g protein-coupled receptors
• tyrosine kinase receptors
• ion channel receptor

Question 8

-plasma membrane receptors that are associated with G proteins

Answer 8

G protein-coupled receptor (GPCR)

Question 9

G protein acts as:

Answer 9

On/off switch

Question 10

Membrane receptors w/enzymatic activity which attach phosphate to tyrosine residues

Answer 10

Receptor tyrosine kinases (RTK)

Question 11

One RTK can activate ____ or more pathways (#)

Answer 11

10

Question 12

Associated w/many types of cancer

Answer 12

Abnormally activated RTKs

Question 13

When gate opens specific ions can pass through

Answer 13

Ion channel receptors

Question 14

Binding of ligand causes:

Answer 14

Conformational change

Question 15

• Found in either the cytoplasm or nucleus

- kind of receptor

Answer 15

Intercellular receptor

Question 16

Signaling molecules must be able to:

Answer 16

Pass through membrane

Be hydrophobic

Question 17

• Relay of signals from receptors to target molecules in the cell
• allows signal to be amplified
• allows for more regulation

Answer 17

Transduction

Question 18

Message is often passed through a change in _______

Answer 18

Protein conformation

Question 19

Phosphorylation=protein _____

Answer 19

Kinases

Question 20

Dephosphorylation= protein_____

Answer 20

Phosphates

Question 21

Small, non protein, water soluble molecules

Can easily spread message throughout cell

Answer 21

Second messenger

Question 22

2 most common second messengers:

Answer 22

1. Cyclic AMP (cAMP)

2. calcium ions (Ca2+)

Question 23

Adenylyl cyclase+ATP–>

Answer 23

cAMP

Question 24

Used as a second messenger in both G-protein and tyrosine kinase receptor pathways

Answer 24

Ca2+

Question 25

_____ causes: muscle contraction, secretion, cell division

Answer 25

Increasing Ca2+

Question 26

Whole point of signal is to tell cell to do something

• usually regulate gene expression
• regulate activity of protein

Answer 26

Step 3: response

Question 27

All cells in your body contain _______ DNA

Answer 27

The SAME

Question 28

Why is a heart cell dif. From a liver cell?

Answer 28

-Dif. genes are turned on in dif. Cells

Dif. cells therefore have dif. proteins

Question 29

Apoptosis

Answer 29

• programmed cell death “Cell suicide”

- eliminates cells that are damaged, infected or at the end of their life span

Question 30

DNA &organelles are chopped up &packaged into vesicles which are engulfed &digested by:

Answer 30

Scavenging cells

Question 31

How could cancer result from a defect in apoptosis?

Answer 31

A damaged cell wouldn’t die because of the defect so it would grow and multiply and become a tumor