cell communication

Question 1

animal cells communicate by:

Answer 1

same cell
direct contact
local distance
long distance

Question 2

same cell communication

Answer 2

autocrine
some cancer cells release their own growth hormone

Question 3

direct contact cell communication

Answer 3

juxtacrine
gap junctions
plasmodesmata

Question 4

local distance cell communication

Answer 4

paracrine
growth factors, neurotransmitters

Question 5

long distance cell communication

Answer 5

endocrine
hormones

Question 6

3 stages of cell signaling

Answer 6

reception
transduction
response

Question 7

reception

Answer 7

detection of a signal molecule (ligand) coming from outside the cell

Question 8

transduction

Answer 8

convert signal to a form that can bring about a cellular response

Question 9

response

Answer 9

cellular response to the signal molecule

Question 10

binding in reception

Answer 10

between signal molecule (ligand) and receptor
HIGHLY SPECIFIC

Question 11

2 types of receptors

Answer 11

plasma membrane receptor
intracellular receptors

Question 12

plasma membrane receptors are

Answer 12

water-soluble ligands

Question 13

intracellular receptors are

Answer 13

in the cytoplasm, nucleus?
hydrophobic or small ligands

Question 14

3 steps in reception

Answer 14

ligand binds to receptor protein
protein changes shape
initiates transduction signal

Question 15

3 types of plasma membrane receptors

Answer 15

g-protein coupled receptors (GPCR)
tyrosine kinase
ligand-gated ion channels

Question 16

GPCR

Answer 16

7 transmembrane segments in membrane
G protein + GTP activates enzyme, triggers cell response

Question 17

tyrosine kinase

Answer 17

attaches (P) to tyrosine
activates multiple cellular responses at once

Question 18

ligand-gated ion channels

Answer 18

signal receptor changes shape
regulates flow of specific ions (Ca2+, Na+)

Question 19

function of transduction

Answer 19

cascades of molecular interactions relay signals from receptors to target molecules

Question 20

protein kinase

Answer 20

enzyme that phosphorylates and activates proteins at next level in transduction

Question 21

what happens when protein kinase phosphorylates

Answer 21

Attached a phosphate group (PO4) to a protein to activate
Only 3 amino acids can be phosphorylated- Threonine (Thr), Serine (Ser), and Tyrosine (Tyr)

Question 22

purpose of phosphorylation cascade

Answer 22

enhance and amplify signal

Question 23

second messengers

Answer 23

small, non-protein molecules or ions that can relay signal inside cell

Question 24

cAMP

Answer 24

cyclic adenosine monophosphate

Question 25

process involving cAMP

Answer 25

GCPR is converted to adenylyl cyclase (converts ATP to cAMP)
activates protein kinase A

Question 26

response functions

Answer 26

gene expression: regulates protein synthesis by turning on and off genes in nucleus
regulates activity of proteins in cytoplasm

Question 27

how is cholera acquired?

Answer 27

drinking contaminated water with human feces

Question 28

what happens after a person contracts cholera?

Answer 28

bacteria (vibrio cholarae) colonizes lining of small intestine and produces toxin
toxin modifies G-protin involved in regulating salt and water secretion
G-protein stuck in active form
intestinal cells secrete salts, water

Question 29

how is cholera dangerous?

Answer 29

infected person develops profuse diarrhea and could die from loss of water and salts

Question 30

apoptosis

Answer 30

cell suicide
dismantled and digested

Question 31

what is apoptosis triggered by?

Answer 31

capase: triggered by signals that activate cascade of “suicide” proteins

Question 32

why does apoptosis happen

Answer 32

protect neighboring cells from damage
animal development and maintenance