Biotransformation 1

Question 1

what needs to happen for a compound to be excreted

Answer 1

it needs to be changed from lipophilic to hydrophilic

Question 2

three reasons to get rid of lipophilic xenobiotics

Answer 2

narcotic effect
accumulation
toxic effects

Question 3

two different kinds of substrates

Answer 3

endogenous

xenobiotics

Question 4

four consequences of biotransformation

Answer 4

increase of hydrophilicity
change of biological activity
increase in molecular weight
activation of compound

Question 5

three principles of biotransformation

Answer 5

enzymatic reactions
often broad substrate specificity
tissue specific expression

Question 6

changes compounds from one form to another

Answer 6

biotransformation

Question 7

process of generating energy from a food source

can be interchanged with biotransformation

Answer 7

metabolism

Question 8

what is being formed during biotransformation

Answer 8

metabolites

Question 9

phase one of biotransformation

Answer 9

introduce, expose a functional group through oxidation hydrolysis and reduction

Question 10

adding a functional group doesn’t really _____

Answer 10

increase hydrophilicity

Question 11

phase two of biotransformation

Answer 11

add hydrophilic group through conjugation reactions

Question 12

reactive functional group added to compounds

Answer 12

epoxide groups

Question 13

six characteristics for cytochrome p450 enzymes

Answer 13

very important group
large number of isoforms
mostly in liver, but found in other tissues
functions: biosynthesis, detoxification, activation
located on ER
all contain heme group at active site

Question 14

two things always needed for basic CYP reaction

Answer 14

oxygen and energy

Question 15

what is located by CYP and provides energy

Answer 15

NADPH cytochrome P450 reductase

Question 16

families 1,2 and 3 CYP deal with

Answer 16

mostly xenobiotics

Question 17

families 4 and up CYP deal with

Answer 17

mostly endogenous substrates

Question 18

inducible, important for metabolism of aromatic hydrocarbons, activation of procarcinogens, EROD assay as specific substrate

Answer 18

CYP1A family

Question 19

induction by phenobarbital

Answer 19

CYP2B

Question 20

oxidation of ethanol, inducible, also uses acetaminophen

Answer 20

CYP2E1

Question 21

high constitutive expression, inducible, very important, numerous substrates, inhibition by grapefruit juice

Answer 21

CYP3A4

Question 22

how does inhibition of CYP happen

Answer 22

through drug-drug interactions

Question 23

what can sometimes form from inhibition of CYP

Answer 23

ROS species

Question 24

explain Ah receptor and CYP1A induction

Answer 24

ligand binding to receptor
changes the AhR conformation
AhR moves into the nucleus which binds with ARNT
binds to DNA at promoter
leads to transcription of mRNA
leads to production of proteins that run phase I and II

Question 25

PCB’s that are _____bind to AhR

Answer 25

in the same plane

Question 26

anther type of aromatic compound can also bind to AhR receptors and disrupt homeostasis

Answer 26

bromine compounds

Question 27

alcohols get broken down into

Answer 27

acids

Question 28

four characteristics of flavin monooxygenases

Answer 28

similar to CYPs but have a flavin group instead
need NADPH and oxygen to run
active at high pH range (8-10)
substrates can often be used by CYPs

Question 29

types of substrates that flavin groups take

Answer 29

mostly secondary and tertiary N, S, and P groups

Question 30

deficiency in FMO3 leads to

Answer 30

fish-odor syndrome, no breakdown of trimethylamine

Question 31

other phase I enzymes that perform hydrolysis

Answer 31

esterases

epoxide hydrolase

Question 32

other phase I enzymes that perform reduction

Answer 32

azo/nitro reduction
quinone reduction
reductive dehalogenation