Amino Acids - Versitile Precursors Flashcards
What 3 molecules is glycine a precursor for?
- Creatine
- Heme
- Purine Bases
What two amino acids are used to form creatine?
Gly and Arg
In what two places does creatine synthesis occur?
- important reactants
- Starts in the kidney and is completed in the liver
1. Kidney (Gly + Arg reaction)
2. Liver (SAM reaction)
Where does creatine go after leaving the liver?
Into the blood and to the:
- Brain
- Muscle
- Heart
What enzyme adds a phosphate to creatine and what is the purpose of this reaction?
- Creatine Kinase (CK)
- It is a high energy store of phosphate
Where is CK found in the highest amounts?
Muscle and Brain
Why is Creatine phosphate a better energy storage form than ATP?
ATP is an allosteric regulator of a lot of enzymes but Creatine Phosphate is not
Where does Creatinine come from?
- Forms Spontaneously from Creatine phosphat and is excreted in the urine
What is indicated by high levels of creatinine in BLOOD?
Kidney Disorder - this means your kidney isn’t putting it in your pee like its supposed to
*Note: Urinary Creatinine is the most widely used measure of muscle mass
What is indicated by high levels of CK?
Myocardial Infarction and strokes
What kind of disorders can be diagnosed by measuring creatine phosphate?
Muscle Disorders
What methyl Donor is used to make Creatine and where does this reaction occur?
- SAM
- LIVER
What is porphyria?
build of of porphorins that results from a defective enzyme on the way to make HEME.
What are some effects of porphyria?
- Nervous System and Skin issues
- Light Sensitivity
What does histadine give rise to?
Histamine
What are the jobs of histamine?
Allergic Response
- Vasodilation
- increased permeability of Blood Vessel walls
Excitatory Neurotransmitter in the brain
Why do antihistamines make you drowsy?
Histamine is an excitatory neurotransmitter in the brain, when its lacking you get drowsy
What 3 things is tyrosine a precursor for?
- Catecholamines
- Melanin
- Hormones
What are the catecholamine?
Dopamine, Epinephrine, Norepinephrine
What are the hormones that tyrosine is a precursor for?
T3 and T4
What is the rate limiting step in turning tyorsine into Dopamine, Norephinephrine, and Epinephrine?
- cofactor involved
- Hydroxylation of Tyrosine (via tyrosine hydroxylase)
- BH4 (tetrahydrobiopterin) = cofactor
What results if melanin cannot be synthesized from tyrosine?
Albinism
How are T3 and T4 made?
- Thyroid protein contains only iodinated tyrosine residues
- iodinated tyrosine residues are cleaved to generate T3 adn T4
Which form T3 or T4 is active in cells?
T3, so all T4 must be cleaved to T3 before it is active
What are the effects of T3?
- Increased heart rate and cardiac output
- Increased basal fuel metabolic rate
What is Trypophan the precursor for?
Melatonin and Serotonin
**Note: these are made in the same pathway
What is the function of melatonin and where is it secreted from?
- Regulates Circadian Rythms
- Light-dark signal transduction
- Sleep induction
-Secreted by Pineal Gland
What is the function of Serotonin?
- Regulated mood control and appetite
**low serotonin results in increased depression and/or increased appetite
What is arginine the precursor for?
Nitric Oxide
What is the function of NO?
Vasodilation
What is glutamate the precursor for?
GABA
T or F: GABA and its precursor glutamate are both neurotransmitters with opposite functions
True
What reaction type converts Glutamate to GABA?
- coefactor (VERY IMPORTANT)
Decarboxylation
COFACTOR = PLP
