protein metabolism Flashcards
what is meant when it is said that amino acids r glucogenic? ketogenic?
if they produce Acetyl Coa which can be used to make ketone bodies>ketogenic
if they produce products than can be used for gluconeogenesis>glucogenic
what is meant by the term “turnover”
how much is the total protein turnover in humans?
all body proteins undergo continuous breakdown and synthesis. it is not a random process.
-300-400g per day
what is the average half-life of a body protein?
80 days
most nitrogen enters the body as________-
and leaves the body as ________
protein
urea
*** RATE OF PROTEIN SYNTHESIS EQUALS DEGREDATION
ok
what is the amino acid pool?
total amount of free aa in the body
what is creatinine? state its function
breakdown product of CREATINE & CREATINE PHOSPHATE in muscle.
- we can use it as an estimate of muscle mass
- and can be used as an indicator of renal function
during 1-2 sec of a vigorous activity, what can supply us with ATP?
creatine phosphate can supply the ATP.
its a very rapidly store of ATP
***CREATINE & CREATININE R DIFFERENT
remember that
describe the nitrogen balance of the body.
in what times would the body have more protein intake that output? and vise versa?
In heakthy adults there is a steady state between amount of N taken and lost. N-BALANCE
Positive N balance= N intake is greater than its loss (active growth,pregnancy, tissue repair)
Negative N balance= N intake is LESS than n loss (starvation, malnutrition, trauma)
in which condition would u see heinz bodies?
G6PDH defiency
amino acid functions
protein synthesis and synthesis of other N compounds. signalling molecules such asNO r formed too.
what is transamination? which enzyme is involved
removal of NH2 from aa, via aminotransferase.
bc its transferring the NH2 group from aa to keto acid (a-ketogluterate
What term is used to describe scarring of the liver caused by continuous long-term liver damage?
Cirrhosis
during the conversion from ethanol/alchohol to acetylaldehyde which energy product is produced?
NADH
Which metabolite can be measured in urine to provide an estimate of muscle mass?
Creatinine is a breakdown product of creatine phosphate and creatine in muscle. It is usually produced at a fairly constant rate and filtered by kidneys into urine. For this reason urine creatinine over a 24 hour period can be used as an estimate of muscle mass.
Which effect would the hormone insulin have on the process of protein degradation (proteolysis)?
Decrease in activity
Think of Insulin as the “hormone of plenty”. If you have just eaten a meal there would be sufficient amino acids derived from the ingested protein so there would be no need to degrade body protein.
Proline is not dietary essential amino acid
Ok
From which amino acid does the body synthesise the hormone adrenaline?
Tyrosine
Which keto acid is used by aminotransferase enzymes to funnel the amino group of other amino acids to glutamate?
α-ketoglutarate
Which aminotransferase enzyme is routinely measured as part of liver function test?
Alanine aminotransferase and aspartate amino transferase enzymes (ALT and AST) are routinely used as part of a liver function test. These liver enzymes are not normally found in plasma so their presence in a blood test gives an indication of liver damage.
Which amino acid is utilised for the transport of ammonia from peripheral tissues to the liver?
Alanine
Ammonia is therefore used to transaminate pyruvate to produce alanine. The alanine is then transported in blood to the liver where it is converted back to pyruvate by transamination.
Which of the following amino acids is NOT dietary essential?
Proline
why is deamination important in terms of different types of aa isomer (hint: D&L form)?
important for dealing with dietary D aa. found in bacteria and plants.
normally, the aa we consume in the bulk of our food and the aa we use to make protein r the L-amino acid form.
so metabolic pathways cannot deal with the D form, so we need to deaminate them before we can use them. otherwise the protein would be non-functional and structurally abnormal.
