rh

Lecture 15 Slides

AMINO ACID CATABOLISM

fig 18-1

fate of amino nitrogen in mammals

fig 18-2

metabolism of amino nitrogen in liver

fig 18-2

nitrogen removal molecules…

fig 18-2

metabolism of amino nitrogen in liver

pg 677

transamination reaction

fig 18-5

fig 18-5

chemistry of the PLP aldehyde:Schiff base formation

fig 18-6

PLP reactions: decarboxylation, deamination, racemazation

fig 18-6

PLP reactions: the transamination two-step...

fig 18-7

oxidative deamination: from amino group to ammonia

fig 18-7 NOT

oxidative deamination: from amino group to ammonia

genetic disorder from loss ofGTP allosteric control…

fig 18-2

metabolism of amino nitrogen in liver

glutamine as a carrier of NH3 from tissue to liver

fig 18-8

fig 18-2

metabolism of amino nitrogen in liver

actual fig 18-9

shuttling ofNH4+ frommuscle toliver

reminiscentof the Coricycle, yes?

fig 18-19

the urea cycleas amethodof safelydisposingof all thatNH3

+

fig 18-10

fig 18-10

logic of the urea cycle: NH4+, aspartate, and CO2

fig 18-11

making a transferable carbamoyl group…

transferring that carbamoyl group…

ornithine

citruline

transfering that carbamoyl group…

citruline

ATP

adding a good leaving group…

using that good leaving group to do chemistry…

using that good leaving group to do chemistry…

fig 18-11

arginine

+ fumarate

production of arginine…

arginine

H2O

urea!! ornithine

liberation of urea…

fig 18-12

coupling between the “Krebs cycles”

fig 18-13

a signal for increased urea production…

pg 689

administering a synthetic allosteric regulator

we must consume amino acids…

fig 18-15

catabolism of amino acids: (most) roads lead to the Krebs cycle

one-carbon metabolism cofactors

fig 18-16

fig 18-16

one-carbon metabolism cofactors

fig 18-16

fig 18-22

amino acids are usedto make many things

fig 18-23

diseases of amino acid catabolism

fig 18-23

an example:pheylketonureaor PKU

fig 18-23

an example:pheylketonureaor PKU

aspartame

AMINO ACIDANABOLISM

it’s alegume!

fixes nitrogen

The nitrogen cycle

fig 22-1

Annamox Bacteria! Nature’s rocket scientists

Box 22-1

Annamox Bacteria! Nature’s rocket scientists

Box 22-1

Annamox Bacteria! Nature’s rocket scientists

Box 22-1Hydrazine-proof chamber

N2

NOxNH4

+

conversionto needed compounds

NH4+

in a.a.

nitrogenfixation

nitrifyingbacteria

plants,somebacteria

mammaliandiet

Usual route of N from atmosphere to mammalian metabolism

fig 22-2

nitrogenaseat the heartof N2 fixation

very sensitiveto O2!!!!!

symbiosis of N2 fixing bacteria

fig 22-4a protected environment: leghemoglobin

fig 22-5

glutamine synthetase

glutamate + ATP + NH4+

glutamine + ADP + Pi

fig 22-6

allostericregulationof glutaminesynthetase

fig 22-7

adenylylation (often “adenylation”)

adenylylation regulates GS, and…

uridylylation regulates adenylylation of GS!!fig 22-7

glutamine amidotransferases

Sglnglu S NH3+

S NH3+

amino acids are synthesizefrom Krebs,glycolysis and pentosephosphatepathways

fig 22-21

classic allosteric regulation of amino acid synthesis

fig 22-22

interlockingregulation ofmultiple pathwaysby allostericregulation

thingsfromaminoacids…

fig 22-27 glutathione!

thingsfromaminoacids…

tyrosineepinephrinenorepinephrinedopamine

glutamategaminobuterate(glutamate)

tryptophan serotonin

neurotransmitters!

arginine NO

thingsfromaminoacids…

arginine creatine

glycine porphyrins

glycine

stop