Chapter 17: Amino Acids (continued) Flashcards
Draw out a diagram for folate metabolism.
Vitamin B12 is reduced and activated in the body to what 2 forms?
- adenosylcobalamin (used by methylmalonyl-CoA mutase)
- methylcobalamin (formed from N5-methyl-THF in the N- methyl THF homocysteine methyltransferase reaction)
The full name for D. latum?
Diphyllobothrium latum
What is D. latum?
a parasite found in raw fish (excess B12 is stored in the body, so deficiencies develop slowly)
What would happen to symptoms of cobalamin deficiency if you gave folate?
It would correct the megaloblastic anemia but does not halt the neuropathy
How does deficiency of Vit. B12 affect the CNS specifically?
causes demyelination of the posterior columns and lateral corticospinal tracts in the spinal cord
What are some symptoms of folate deficiency?
megaloblastic anemia
- macrocytic anemia
- MCV > 100 femtoliters (fL)
- PMN nucleus more than 5 lobes
Homocysteinemia with risk for cardiovascular disease
- NTD
What are some causes of folate deficiency?
- pregnancy (NTD)
- alcoholism
- severe malnutrition
- gastric or terminal ileum resection
What are some of the symptoms of Vit B12 deficiency?
macrocytic anemia
MCV > 100 femtoliters (fL)
PMN nucleus more than 5 lobes
Homocysteinemia with risk for CVS disease
methylmalonic aciduria
progressive peripheral neuropathy
Compare the time it takes for folate deficiency and B12 deficiency to be evident?
3-4 months folate while B12 deficiency normally takes years to develop
What are some specialized products that tyrosine can make?
- thyroid hormones T3 and T4
- melanin
- catecholamines
What are some specialized products in the body that tryptophan can make?
serotonin and NAD NADP (niacin)
What are some specialized products that arginine can make?
Nitric oxide (NO)
What are some specialized products that glutamate can make?
y-aminobutyric acid (GABA)
What are some specialized products histidine can make?
histamine
Draw out the pathway for catecholamine synthesis.
Name some products in the body in which heme proteins are included?
hemoglobin
myoglobin
all the cytochromes (ETC)
cytochrome P-450, cytochrome b5
the enzymes catalase, peroxidase, and the soluble guanylate cyclase stimulated by NO
What is the rate-limiting enzyme for heme synthesis?
δ-aminolevulinate synthase (ALA)
Are compounds with an “ogen” at the end of their name colorless or colorful?
Compounds such as urobilinogen, are colorless
Are compounds with the suffix such as urobilin colorful or colorless?
colorful
How does a compound like urobilinogen change to urobilin and get color?
In the presence of O2, they spontaneously oxidized
Draw out the pathway for heme synthesis.
What are some symptoms of acute intermittent porphyria? What would increase on labs?
- episodic, variable expression
- anxiety, confusion, paranoia
- acute abdominal pain
- port-wine urine in some patients
- paralysis
- motor sensory or autonomic neuropathy
- weakness
- excretion of ALA (d-aminolevulinic) and PBG (porphobilinogen) during episodes
What is a drug you can never give individuals with acute intermittent porphyria?
never give barbituates
What are some symptoms of porphyria cutanea tarda?
- most common porphyria
- photosensitivity
- inflammation, blistering, shearing of skin in areas exposed to sunlight
- hyperpigmentation
- exacerbated by alcohol
- red-brown to deep-red urine (tea colored urine)
What are other names for acute intermittent porphyria?
- porphobilinogen deaminase deficiency
- hydroxymethylbilane synthase deficiency
Inheritance pattern of acute intermittent porphyria?
AD
When, in a humans life, will acute intermittent porphyria typically appear?
late onset
T/F. Some of the individuals suffering with acute intermittent porphyria are incorrectly diagnosed and placed in psychiatric institutions.
True
Do individuals with acute intermittent porphyria have photosensitivity?
no