Protein And Amino Acid Metabolism Flashcards
Name a few major nitrogen containing compounds
- amino acids
- proteins
- purines /pyrimidines
- DNA/RNA
What is creatinine and why is it used as a clinical marker ?
- during the day , creatine and creatine phosphate is broken down into creatinine
- usually produced at a constant rate
- filtered by the kidneys into urine
- creatinine urine excretion over 24h is proportional to muscle mass
- also used as an indicator of renal fUnction
What is the reference range of creatinine excreted in urine
Per day ?
Men :14-26 mg/kg
- women : 11-20 mg/kg
What does N equilibrium mean
Nitrogen intake = nitrogen output
- normal state in an adult , where there is no change in total body protein
Positive N balance
Intake > output
- increase in total body protein
- this is often occurs during pregnancy as there is a fetus growing inside or during a growth period or an adult recovering from malnutrition
Negative N balance
Intake < output
- net loss of body protein
- never normal
- causes are often trauma , infection or malnutrition
What are the two outcomes for free amino acids ?
- they enter the liver
1) Amino group (-NH2) removed which then undergoesu deamination in the liver.
2) the rest of the amino acid is used to form part of the carbon skeleton in organic compounds. Amino acids can be categorised into glucogenic or ketogenic amino acids.
What are ketogenic amino acids ?
Ketogenic amino acids are amino acids that go on to form acetyl-coA which is involved in ketogenesis
What are the TWO exclusive ketogenic amino acids ?
1) lysine
2) leucine
What are glucogenic amino acids?
Amino acids that can be converted into glucose via gluconeogensis
What are a few examples of exclusive glucogenic amino acids ?
1) methionine
2) valine
3) glutamate
What are a few examples of amino acids that are both ketogenic and glucogenic ?
- tyrosine
- tryptophan
- threonine
In a 70kg man , what is the energy content of TAGS?
600,000Kj
in a 70kg man , what is the energy content of glycogen ?
4000 KJ
What is the energy content of muscle protein in a 70kg man ?
100,000 KJ
When would we use our protein reserves ?
Occurs during extreme stress ( starvation )
Under what control is the mobilisation of protein reserves
Hormonal
Insulin and growth or one release increases or decreases protein degradation?
Decreases
Insulin and growth hormone increases or decreases protein synthesis
Increases
Glucocorticoid(cortisol) release increases or decreases protein synthesis
Decreases
Glucocorticoids(cortisol) increases or decreases protein degradation?
Increases