Lec 5 - Nitrogen Metabolism Flashcards by Francis Mendoza

there are blank aa that are essential from diet

How well did you know this?

Not at all

Perfectly

the body cannot store this

protein

How well did you know this?

Not at all

Perfectly

essential aa mnemonic

pvt tim hall

How well did you know this?

Not at all

Perfectly

pvt tim hall

phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, arginine, leucine, lysine

How well did you know this?

Not at all

Perfectly

a child is in blank nitrogen balance which allows for blank

positive, growth

How well did you know this?

Not at all

Perfectly

a normal adult is in blank nitrogen balance

equal

How well did you know this?

Not at all

Perfectly

not enough nitrogen in our diet causes blank nitrogen balance

negative

How well did you know this?

Not at all

Perfectly

average man needs blank grams of nitrogen per kg of body weight

How well did you know this?

Not at all

Perfectly

appears in the weaned child who was nourished with an adequate caloric diet but deficient in protein and characterized by hair changes, skin disorders, hepatomegaly

kwashiorkor

How well did you know this?

Not at all

Perfectly

deficiency of both protein and calories characterized by wasting away of subcutaneous fat and muscles and lack of growth and development

marasmus

How well did you know this?

Not at all

Perfectly

putting a protein in an acidic environment causes this

denaturation

How well did you know this?

Not at all

Perfectly

pepsinogen makes pepsin which is an enzyme with specificity for these

Phe, Tyr, Trp, Leu

How well did you know this?

Not at all

Perfectly

intracellular protein degradation that requires energy

atp dependent proteolysis

How well did you know this?

Not at all

Perfectly

intracellular protein degradation that does not require energy

atp independent proteolysis

How well did you know this?

Not at all

Perfectly

atp independent proteolysis uses these

extracellular proteins, lysosomes, cathepsins

How well did you know this?

Not at all

Perfectly

atp dependent proteolysis uses these

intracellular proteins

How well did you know this?

Not at all

Perfectly

E1 is the blank enzyme atp dependent proteases

activating

How well did you know this?

Not at all

Perfectly

E2 is the blank enzyme atp dependent proteases

conjugating

How well did you know this?

Not at all

Perfectly

E3 is the blank enzyme in atp dependent proteases

ubiquitin protein ligase

How well did you know this?

Not at all

Perfectly

the only essential fatty acids in diet

omega 3, omega 6

How well did you know this?

Not at all

Perfectly

we get nitrogen from the blank we take in

aa (amine nitrogen)

How well did you know this?

Not at all

Perfectly

major end product of amino nitrogen metabolism in body

urea

How well did you know this?

Not at all

Perfectly

less numerous things in urine

ammonia, creatinine, uric acid

How well did you know this?

Not at all

Perfectly

uric acid is the end product of blank

purine metabolism

How well did you know this?

Not at all

Perfectly

two aa that are semi essential

histidine, arginine

pepsin, trypsin, elastase, chymotrypsins are all blank so they are not activated until they leave their cell of origin

zymogens

brush border cells of SI release blank

enteropeptiase

enteropeptidase converts blank to blank

trypsinogen, trypsin

atp dependent proteolysis occurs in blank and targeting of a protein to proteosomes requires blank

pretoasomes, ubiquitin

atp independent proteolysis occurs in blank by proteases called blank

lysosomes, cathepsins

caspace and calpains are proteolytic enzymes involved in blank

apoptosis

group specific transporters for aa

small neutral, large neutral, basic, acidic, proline/glycine

three ways to transport aa

glutamyl cycle, group specific, facilitated

facilitated transport is blank transport

secondary active transport

aa transport that has been seen in brain, intestine and kidney

glutamyl cycle

blank is required for optimal activity of glutamyl transferase

sodium

all aa except these two can participate in transamination reacts

threonine, lysine

most nitrogen of aa appears in the form of blank due to action of transaminases

glutamate

glutamate is subject to oxidative deamination by blank

glutamate dehydrogenase

transaminases have an equilibrium near blank which is an advantage

two most common transaminases

aspartate aminotransferase (GOT), alanine aminotransferase (GPT)

cofactor involved in many enzyme catalyzed transformations of aa

pyridoxal phosphate

disposing amino group from aa can be via blank or blank deamination

oxidative, non oxidative

non oxidative deamination enzymes require blank

PLP pyridoxal phosphate

L amino acid oxidase catalyzes reactions with L aa except these two

serine, threonine

d amino acid oxidase is in the liver and kidney and is blank because it can be in glycine metabolism or metabolize d aa from bacterial cell walls

enigmatic

A group of pyridoxal phosphate dependent dehydratases catalyze the removal of the amino groups of serine, threonine, cysteine and histidine to form keto acids and NH3.

nonoxidative deamination

this enzyme is in the cytosol and uses NADPH as a reductant for catalyzing a reversible reaction to trap ammonia during AMMONIA FIXATION

glutamate dehydrogenase

liberatiing glutamine from ammonia is done by blank

glutaminase

the only compound that can be completely oxidized by the krebs cycle

acetate via acetyl coA

except for amino acids which yield acetyl-CoA directly, all amino acids must be converted to blank prior to complete oxidation

pyruvate

most aa are ketogenic or glucogenic

glucogenic

aa whose carbon skeletons are converted to acetly coA may be used to form acetoacetate which is called blank

ketogenic

acetoacetate is a blank

ketone

ACETATE CANNOT GIVE RISE TO THE NET SYNTHESIS OF blank ALTHOUGH THE CARBONS FROM ACETATE CAN APPEAR IN blank

GLUCOSE

oxaloacetate is a blank in the krebs cycle

catalyst

net result of a turn of the TCA cycle

oxidation of acetate NOT oxaloacetate

urea formation occurs here

liver

this is located in the liver mitochondria and uses ammonia as the nitrogen donor in the urea cycle

carbamoyl phosphate synthetase I

this is present in the cytosol and is involved in pyrimidine synthesis

carbamoylphosphate synthetase II

this is in the urea cycle and catalyzes first step in arginine synthesis

ornithine transcarbamoylase

this is part of the urea cycle and catalyzes the reaction leading to the formation of argininosuccinate from citrulline and aspartate and requires atp

argininosuccinate synthetase

this cleaves arininosucccinate in the urea cycle to arginine and fumarate

argininosuccinase

part of the urea cycle where urea is made by the simple hydrolysis of arginine which is catalyzed by blank

arginase

this is a regenerating cycle much like oxaloacetic acid in the citric acid cycle

ornithine

lacking an enzyme of the urea cycle would lead to blank

ammonia toxicity

example of short term regulation of urea cycle by allosteric regulation of carbamoyl phosphate synthetase I by blank

nacetylglutamate

induction of the enzymes is an example of blank and an example is an increase in protein in the diet over several days

long term control

allosteric control of concentration of substrates in urea cycle is known as allosteric control and is blank

short term

arginine can be converted to citrulline and nitric oxide by blank

nitric oxide synthase

each enzyme subunit of nitric oxide synthase contains one blank and one blank and one blank and one blank

FMN, FAD, tetrahydrobiopterin, FE III heme

nitric oxide functions as a blank signal in regulation of vessel dilation and serves as a neurotransmitter

intracellular

ornithine can also be derived from blank and is used for synthesis of polyamines like putrescine

arginine

ornithine is coverted to putrescine by blank

ornithine decarboxylase

three aa that are used for synthesis of creatine

glycine, arginine, methionine

creatine and creatine phosphate can be converted back and forth to each other by blank

creatine kinase

first step of making creatine occurs is blank and blank and the methylation step occurs in the blank

kidney, pancreas, liver

excretion of creatinine in urine in a normal human is almost blank

constant

cancer chemotherapy is often directed at blank metabolism

FH4

blank is a one carbon carrier in one carbon metabolism

tetrahydrofolate

one carbon metabolism refers to sources of one carbon in more blank form than carbon dioxide

reduced

blank is a source of methyl groups in one carbon metabolism

s adenosylmethionine

the methylated derivative of FH4 is a blank because the reaction is irreversible

methyl trap

first step in synthesis of porphyrins

ALA synthase in mitochondria

porphobilinogen is synthesized by using this enzyme

ALA dehydrase

heme synthesis is accomplished via blank

porphyrins