Lecture #11

Question 1

What compound is this?

Answer 1

nicotine

Question 2

developmental stages are seen as being fragile, but…

Answer 2

there are many cases of very tough embryos (ex: brine shrimp, killifish)

Question 3

development is adapted to…

Answer 3

the historic/expected environment of the embryo

Question 4

heat shock proteins (HSP)

Answer 4

-deal with protein damage -triggered by heat shock factor (turns on when senses denatured proteins) -work by recognizing and binding to denatured proteins)

Question 5

cytochrome p450 enzymes

Answer 5

-metabolize toxic molecules -triggered by arylhydrocarbon(AhR) receptor

Question 6

MDRs/OATs

Answer 6

-eliminate foreign compounds -MDRs activated by nuclear hormone receptor

Question 7

GSH/MT/GST

Answer 7

-glutathione and metallothionein bind toxins until they can be eliminated -act as “sponges”

Question 8

cognate HSPs

Answer 8

present all the time

Question 9

inducible HSPs

Answer 9

-triggered by need for more HSPs -HSP detaches from heat shock factor after sensing denatured protein and goes to bind to that, HSF goes to the nucleus and turns on more expression of the HSP

Question 10

cellular thermometer hypothesis

Answer 10

HSP gene expression is linked to the dissociation temperature of the HSF complex

Question 11

Why do we get fevers?

Answer 11

-indicator to activate stress response bc something is very wrong -deals with the damage the infection causes

Question 12

xenobiotic metabolism

Answer 12

phase 0: transport (prevent from entering) (ABCB1) phase 1: hydrolysis, reduction, or oxidation phase 2: conjugation (like with glutathione) phase 3: transport (remove from body) (ABCB1)

Question 13

major detoxification organ

Answer 13

liver

Question 14

xenobiotic metabolism transformation usually involves…

Answer 14

making hydrophobic things more water soluble

Question 15

cytochrome p450 pathway

Answer 15

-located on endoplasmic reticulum of most cells -highly enriched in the liver -oxidize lipophilic molecules to make them easier to excrete

Question 16

arylhydrocarbon receptor

Answer 16

-binds to organic molecules (toxins) and translocates to nucleus -a transcription factor -triggers cytochrome p450s -breaks down molecules like dioxins/PCBs

Question 17

What compound is this?

Answer 17

dioxin (contaminant in Agent Orange) -persistent, high Kow

Question 18

Cellular defenses are always…

Answer 18

evolving to better fit the environment

Question 19

August Krogh

Answer 19

-Danish physiologist -awarded Nobel Prize for discovery of perfusion mechanisms in capillaries -concept that “for many problems, there is an animal in which it can most conveniently be studied”

Question 20

sodium potassium ATPase

Answer 20

-accounts for more than 70% of the energy budget of a cell -discovered by Jen Skou in the leg nerves of Shore Crabs (won Nobel Prize for this)

Question 21

action potential

Answer 21

-necessary for conductivity of neurons, eggs, etc.. -sodium rushes into cells –> depolarization -potassiums rushes out –> repolarization -discovered in squid giant axon because the axon was unusually large enough to insert a sensor

Question 22

green fluorescent protein

Answer 22

-can be used as a genetically encoded tag to label membrane proteins -discovered by Roger Tsien (received Nobel Prize) -discovered and purified from a jellyfish

Question 23

cell division

Answer 23

-first discovered cyclins(binding proteins necessary for cell division) in sea urchins (won Nobel Prize) -bc sea urchins divide very synchronously, easy to observe with many of them

Question 24

babies are created with sperm and egg, one from each parent

Answer 24

-wasn’t accepted until sea urchins were studied bc the fertilization occurs outside of the organism’s body and can be observed more easily -no Nobel Prize awarded

Question 25

deuterostomes

Answer 25

-ex: sea urchin -different than protostomes bc anus forms first

Question 26

sea urchins

Answer 26

-very long lived -virtually no senescence - old sea urchins can still reproduce well -usually purple urchins studied -extensively study process of fertilization in them

Question 27

how macrophages work

Answer 27

-immunology -first described in sea stars -Nobel Prize