Proteins Metabolism

Question 1

Kwashiorkor

Answer 1

Protein deficiency but adequate calories

Question 2

Famine edema

Answer 2

Inadequate synthesis of plasma proteins, mostly albumin, so fluid escape into tissues

Question 3

Marasmus

Answer 3

Protein energy malnutrition
Protein calorie deficiency
Starvation

Question 4

Protein malnutrition causes in developed countries

Answer 4

Prégnant and lactating mothers 
Eating disorders 
Alcoholism 
Drug addicts 
Hospital patients 
Elderly and chronically ill
Genetic disorders

Question 5

Essential amino acids

Answer 5

Mnemonic PVT TIM HALL

Arg
His
Île
Leu
Lys
Met
Phy
Thr
Trp 
Val

Question 6

Non essential amino acids

Answer 6

Ala
Asn 
Asp
Cys 
Glu 
Gln 
Gly 
Pro 
Ser 
Tyr

Question 7

Amino acids requirements

Answer 7

No significant storage

Depends on age sex and activity

Question 8

2 fates of amino acids degradation

Answer 8

Amino acids can produce NH4 or carbon skeleton

NH4 can

• enter biosynthesis of AA, nucleotides, amines
• enter urea cycle

Carbon skeleton become a-ketoacids which can enter citric acid cycle —> OAA can be formed and undergo gluconeogenesis

Question 9

What is glycogenic AA

Answer 9

Product of AA degradation can enter gluconeogenesis

Question 10

Ketogenic AA degradation

Answer 10

Ketogenic AA degradation products are intermediates of lipid metabolism or ketone bodies

Question 11

AA purely ketogenic

Answer 11

Leucine

Lysine

Question 12

AA both ketogenic and glucogenic

Answer 12

Isoleucine
Phenylalanine
Tyrosine
Tryptophan

Question 13

Products of glucogenic AA breakdown

Answer 13

Pyruvate 
a-ketoglutarate
Succinyl coa 
Fumarate 
OAA

Question 14

Products of ketogenic AA breakdown

Answer 14

Acetyl coa

Acetoacetate

Question 15

Healthy adult nitrogen balance

Answer 15

Excretion of nitrogen equals intake

Question 16

4 majors reaction of AA

Answer 16

Transamination

Oxidative deamination

Decarboxylation

Transdeamination

Question 17

Transamination

Answer 17

Transfer of NH2 to form another AA

Question 18

Enzyme in transamination

Answer 18

Transaminase

AA1+ aketoacid 2<===> aketoacid1+ AA 2

Question 19

Transaminase cofactor

Answer 19

Pyridoxal phosphate derived from vit b6

Question 20

Major AA In AA metabolism

Answer 20

aketoglutarate
Gln
Glutamate

Question 21

Most abundant AA serving as neural transport and storage form of ammonia

Answer 21

Glutamine

Question 22

Glutamate dehydrogenase action

Answer 22

Glutamate + NADP+ H2O <==> aketoglutarate+ NADPH + NH4+

Question 23

Glutamine synthétase action

Answer 23

Glutamate + ATP + NH4+ —-> glutamine + ADP + pi

Question 24

Glutaminase action

Answer 24

Glutamine —-> glutamate

Question 25

Amino Acid oxidase

Answer 25

Amino acid + FAD + H2O —-> aketo acid +NH3 + FADH2 FADH2 + O2 —-catalase—> FAD + H2O2

Question 26

Decarboxylation

Answer 26

CO2 removed from glutamate to form GABA

Question 27

Transdeamination

Answer 27

Coupling of aminotransferase with glutamate dehydrogenase Lead to formation of pyruvate

Question 28

Tryptophan metabolized to

Answer 28

Alanine Acetyl coa CO2 Formate Small amount to serotonin , niacin, melatonin

Question 29

AA precursors of

Answer 29

Protein synthesis Active metabolites Metabolic fuels

Question 30

Serotonin

Answer 30

Neurotransmitter which impacts behavior such as appetite , aggression, sleep, sensory perception, depression Potent vasoconstrictir of Blood vessels’ Helps in circadian cycle

Question 31

Antidepressants that inhibits serotonin reuptake

Answer 31

Paxil Prozac Zoloft

Question 32

...... is a structural agonist that potential es effect of serotonin

Answer 32

LSD

Question 33

Hartnups disease

Answer 33

Defect in transportation or absorption of AA in intestines Defect in reabsorption un renal tubules of kidney High urine concentration of essential amino acids Symptoms : Hereditary pellagra like skin rash Cerebellar ataxia temporary Constant renal amino aciduria 3 D Dermatitis Dementia (20%) Diarrhea

Question 34

Direct source of ammonia in liver

Answer 34

Glutamate Glutamine ( from other tissues) Alanine ( from muscles )

Question 35

Major contributor to waste nitrogen

Answer 35

Muscle

Question 36

Nitrogen waste products

Answer 36

Urea in vertebrates Uric acid in birds and reptiles

Question 37

Carbamoyl phosphate synthesis and entry into urea cycle

Answer 37

HCO3- + NH4+ gives carbamoyl phosphate