Unit 2

Question 1

what 3 attributes make a molecule a target?

Answer 1

1. endogenous (within org. being targeted)
2. reactivity
3. steric configuration (shape)

Question 2

why are lipids important in cells?

Answer 2

forms the plasma membrane that rigidifies cells

Question 3

what are the most common target molecules of toxins?

Answer 3

proteins

Question 4

lipid structure

Answer 4

polar head and nonpolar tail

Question 5

how is jaundice formed?

Answer 5

liver enzymes spill into the blood

Question 6

how does Tylenol cause toxicity?

Answer 6

NAPQ1 (toxic/reactive metabolite) is formed and destroys hepatocytes

Question 7

noncovalent bonds

Answer 7

hydrogen bonds, key/lock fit
reversible

Question 8

TCDD

Answer 8

dioxin

Question 9

AhR

Answer 9

aryl hydrocarbon receptor

Question 10

covalent bonds

Answer 10

irreversible bonds because e- are shared between toxicant and molecule
metal ions

Question 11

free radicals (O-)

Answer 11

superoxides are missing an e- which makes them unstable, so they seek an e- from other cells, causing damage

Question 12

antioxidants

Answer 12

donate an e- to the free radical, making it stable and neutralizing it, reducing damage

Question 13

hydrogen abstraction

Answer 13

toxicants can remove H from endogenous molecules, making it reactive (“unhappy”)

Question 14

how does nitrogen dioxide affect proteins?

Answer 14

it can “steal” hydrogen atoms from tyrosine residues in proteins to form 3-nitrotyrosines which cause protein disfunction

Question 15

nitrogen dioxide exposure

Answer 15

exhaust from car engines and cigarette smoke attacks the respiratory system

Question 16

electron transfer

Answer 16

e- moves from one molecule to another (changing the charge state)
most common with transition metals

Question 17

methehemoglobinemia

Answer 17

Fe2+ randomly transitions to Fe3+ (methehemoglobin), which cannot carry oxygen
result is hypoxia

Question 18

what are the presenting signs of hypoxia?

Answer 18

blue mucous membranes and skin
blood turns chocolate brown

Question 19

ricin

Answer 19

glycosidase that destroys linkages in ribosomal RNA

Question 20

botulinum toxin

Answer 20

a protease that destroys vesicle fusion
NTs that contract muscles are inhibited
leads to flaccid paralysis

Question 21

what are the two outcomes of toxin reactions?

Answer 21

1. dysfunction
2. degradation/destruction

Question 22

what are some normal cell functions?

Answer 22

ATP synthesis
Ca2+ regulation
protein synthesis
microtubular function
membrane function

Question 23

what happens in impaired internal maintenance?

Answer 23

changes in basic functions of a cell, such as energy metabolism, DNA/protein synthesis, or organelle synthesis

Question 24

what are the major events of impaired internal maintenance?

Answer 24

ATP depletion –> death
hypercalcemia (intracellular)
O- increase

Question 25

what happens in impaired external maintenance?

Answer 25

changes in one tissue lead to toxicity in other tissues, such as the liver or endocrine glands

Question 26

what is the role of coagulation?

Answer 26

to prevent excessive blood loss

Question 27

what can cause hypercalcemia?

Answer 27

cancer or parahyperthyroidism

Question 28

what is cisplatin?

Answer 28

a platinum-containing compound used to treat cancer it bonds tightly w/ nitrogen in the DNA, "kinking" it and causing cell death

Question 29

what are the 4 toxin types of snake venom?

Answer 29

hemotoxic, cytotoxic, neurotoxic, proteolytic

Question 30

hemotoxic

Answer 30

targets RBCs and vessels to cause fatal bleeding (activating or inhibiting blood clotting)

Question 31

cytotoxic

Answer 31

attacks cell/tissue to digest prey

Question 32

neurotoxic

Answer 32

attacks the nerves/brain or inhibits NTs, leading to paralysis or heart attack

Question 33

proteolytic

Answer 33

enzymes make site of a bite undergo proteolysis to attack cells, muscles, and tissues

Question 34

what is the result of oxidative phoshorylation?

Answer 34

synthesis of ATP

Question 35

peritoneum

Answer 35

thin/transparent membrane that lines the walls of the abdominal cavity

Question 36

what stimulates ATP synthase in oxidative phosphorylation?

Answer 36

the accumulation of h+ byproducts as a result of redox reactions

Question 37

what causes oxidative stress?

Answer 37

if ROS are so elevated that the antioxidant system is overwhelmed

Question 38

what is the result of oxidative stress?

Answer 38

molecular damage and cell death

Question 39

what are examples of disrupted intracellular cell maintenance?

Answer 39

disrupted oxidative phosphorylation and ATP synthesis accumulation of free radicals oxidative stress disrupted Ca+ homeostasis

Question 40

is there more Ca+ intracellular or extracellular?

Answer 40

extracellular mitochondria express a low-affinity Ca2+ transporter to actively remove Ca from cytoplasm

Question 41

how can toxicants disrupt Ca2+ concentration in the cytoplasm?

Answer 41

open ligand/voltage-gated Ca+ channels or damage plasma membranes, so Ca2+ readily moves down the conc gradient into the cytoplasm can cause leaks in the mitochondria or ER can diminish Ca2+ efflux by inhibiting Ca2+ transporters

Question 42

cytoskeleton

Answer 42

microscopic network of protein filaments/tubules in the cytoplasm that gives the cell its shape

Question 43

how does increased intracellular Ca2+ cause cell death?

Answer 43

- uncontrollable release of NTs - ATPase enzymes activated - proteases activated, damaging cytoskeleton and leading to membrane calcification

Question 44

what are the messengers of a) the nervous system b) the endocrine system

Answer 44

a) electrical impulses b) chemical hormones

Question 45

what are the 3 components of the endocrine system?

Answer 45

hormones, target cells, and endocrine cells

Question 46

what does the pancreas produce?

Answer 46

glucagon and insulin

Question 47

what does the thyroid produce?

Answer 47

the thyroid hormone, which controls the body's metabolism

Question 48

adrenal glands produce ___

Answer 48

epinephrine + norepinephrine

Question 49

ovaries produce ____

Answer 49

estrogen- a steroid hormone that maintains female bodily functions

Question 50

testes produce ______

Answer 50

testosterone- a steroid hormone that develops male sexual characteristics

Question 51

amine hormone

Answer 51

AAs w/ modified group; norepinephrine

Question 52

peptide hormone

Answer 52

any chain of linked AAs; oxytocin

Question 53

steroid hormone

Answer 53

derived from the lipid cholesterol; progesterone

Question 54

endocrine

Answer 54

hormones that communicate to distant cells

Question 55

paracrine

Answer 55

hormones that communicate to neighboring cells

Question 56

autocrine

Answer 56

hormones that act on self

Question 57

endocrine disrupting chemicals (EDCs)

Answer 57

natural/synthetic chemicals that interact w/ the endocrine system and influence its function in detrimental ways

Question 58

sex hormone binding globulin

Answer 58

produced in the liver and binds to testosterone and estradiol

Question 59

thryroid (thyroxine) binding globulin

Answer 59

produced in the liver and binds to thyroid hormone in circulation, carrying T4

Question 60

cortisol binding globulin (CBG or transcortin)

Answer 60

produced in the liver and binds to cortisol, progesterone, aldosterone and carries >90% of the plasma

Question 61

albumin

Answer 61

produced in the liver and transports thyroid hormones, minerals, or FAs to liver