Amino Acid Metabolism

Question 1

what do we need to do before we metabolise AA

Answer 1

remove the amino group via transamination and deamination

Question 2

tran

Answer 2

transfer amine group from the amine group of aa and swap with the =O of ketoacid

Question 3

how is tran helpful?

Answer 3

mostly converted to glutamate / aspartame

and they can easily be inserted into the urea group which allows for them to bereaved more safely

Question 4

formula and enzymes for the 2 types of the transamination reactions

Answer 4

• ALT ; Alanine + a-ketoacid = a-ketoacid + glutamate
• AST ; glutamate + oxaloacetate = a-ketoacid + aspartate
• enzymes = AST / ALT
• cofactor = pyridoxal phosphate a vitamin B derivative

Question 5

clinical releveance

and example

Answer 5

blood test look for AST ALT for liver functioning ^ in liver damage/ toxicity/ autoimmune liver disease / amanita phalloides mushrooms is toxic to liver so ^AST/ALT observed

Question 6

deamination

Answer 6

remove amine group as free ammonia (NH3)

occurs in liver and kidney (urea cycle in the liver)

Question 7

importance of deamination

Answer 7

for metabolism is dietary D-amino acids into L amino acids so in can be used by the body (found in plants and microorganisms)
- ammonia must be removed by the body since its very toxic, so it is ultimately converted into urea and removed in the urine

Question 8

enzymes

Answer 8

aa oxidase
glutamate dehydrogenase
glutaminase

Question 9

urea

Answer 9

high nitrogen content 2 amine groups
innert in humans but bacteria can convert it to ammonia
important in removal of nitrogen + osmotic role in kidney tubules

Question 10

urea cycle enzymes and their control pattern

Answer 10

5 enzymes

down regulated with low N (protein) , unregulated with ^ N (protein)

Question 11

high protein diet/ low

clinical condition

Answer 11

up regulated
down regulated
referring syndrome; td to low protein diet their urea enzymes were down regulated and therefore eating a rich protein diet rapidly there wasn’t sufficient capacity in the urea cycle to deal with the ammonia levels

Question 12

risk factors of referring syndrome

treatment

Answer 12

• physiological issues i.e wasn’t eating
• malnourished
• marasmums
• BMI <16
• 5 to 10kcal/kg/day increase gradually through the week

Question 13

N metabolism involved

Answer 13

N balance and Protein turnover

Question 14

major N containing compaoitn

Answer 14

CK
PURINE AND PYRIMINDE
NT (dopamine)
Proteins 
hormones (adrenaline)

Question 15

CK

Answer 15

immediate source of ATP
CK => creatinine and
found heavily in skeletal muscle and heart
Creatinine is the clinical marker
rate produced is proportional to the mass men (14-26
W 1-20mg/kg b males have more muscles than men

Question 16

other reasons why CK used as marker

Answer 16

• measure heart damage post MI (b not often instead troponin is used b CK nonexclusive to the heart)
• kidney damage ( b urine removes it, ^ CK suggest kidney failure of sorts)

Question 17

N

Answer 17

2kg
free state (not in aa)
input 16g N from diet
output 2g nails, hair / 14g faces and urine

Question 18

what is nitrogen balance

Answer 18

the balance between N in and out the body
N+ = more in than out , normal d muscle builder or pregnant or adult recovering from malnourishment
N- = less intake than outtake , not normal causes malnourishment, trauma, infection

Question 19

P turnover

Answer 19

free amino acid pool (added from thebe diet/ de novo (make it yourself) )
this free AAused to synthesis P which then are broken down via proteolysis
these AA are a source of carbon dn therefore can used to generate energy like FA can but you must remove amine group tho first to stop amine formation, this is done in the liver and the amine group can be converted into urea and removed in urine , but the C skeleton can be used depending on whether its a ketogenic or glutogenic AA can be used to either from ketone bodies (ketogenic AA) or gluconeogenesis (glycogenic AA) ,these from energy

Question 20

ketogenic and glycogenic AA

Answer 20

K = lysine and lueocine
G = Alanine, cysteine

Question 21

when and how do we mobilise these P reserves

Answer 21

• in extreme starvation
• controlled by hormones ;
• Insulin and growth hormone ^ P synthesis ^ P degradation
• Glucocorticoids e.g cortisol v P synthesis ^ P degradation

Question 22

clinical conditon associated with control over mobilising P

Answer 22

Cushing’s syndrome = excess cortisol therefore ^ firstly overweight due t ^ cortisol and so their skin stretches but due to ^ P degradation p has STRIAE as structure of the skin is weakened

Question 23

Who needs specific aa and what is it called?

Answer 23

pregnant androids need arginine, tyrosine, cysteine d ^ rate of P synthesis
known as conditionaly essential

Question 24

Who needs specific aa and what is it called?

Answer 24

pregnant androids need arginine, tyrosine, cysteine d ^ rate of P synthesis
known as conditionally essential