Nutrition/Metabolism Flashcards
What are the most toxic vitamins when given in excess?
Vitamins A & D
What happens to cats with vitamin A deficiencies?
Retinal degeneration/vision loss
What happens to cats with vitamin B1 deficiencies?
Neck ventroflexion, polyneuritis
Niacin is an (essential/non-essential) dietary nutrient for cats. Why?
- Essential
2. They are unable to use tryptophan as a precursor for niacin synthesis
What are the essential fatty acids?
- Linoleic (n-6)
2. Linolenic (n-3)
What is the preferred metabolic fuel for enterocytes?
Glutamine
What are the essential amino acids?
“PVT TIM T. HALL”
- Phenylalanine
- Valine
- Tryptophan
- Taurine (cats only)
- Isoleucine
- Methionine
- Threonine
- Histidine
- Arginine
- Leucine
- Lysine
Vitamin A activity is dependent on ____.
Zinc
What are the functions of Vitamin B1
Required for metabolism of carbohydrates and energy production
* Major cofactor for the TCA cycle and pentose phosphate pathway → major sources of energy for neurons
Vitamin B2 (riboflavin) is involved in the synthesis of ____ and _____.
- FAD
2. FMN
What kind of anemia can be seen with a Vitamin B12 deficiency?
- Pernicious anemia (macrocytic megaloblastic anemia)
What are important functions of folate?
- Essential for synthesis of purines and pyrimidines → therefore DNA synthesis
What kind of anemia can be seen with folate deficiency?
Macrocytic megaloblastic anemia
Why do vitamin B12 and folate deficiencies cause anemia?
- B12 is needed for the conversion of folate to tetrahydrofolate → a B12 deficiency can therefore mimic a folate deficiency
- Folate is needed to create purines and pyrimidines which are needed for DNA synthesis
- In a folate deficiency, impaired DNA synthesis in erythroblasts causes erythroblast apoptosis → also associated with ineffective erythropoiesis
Vitamin C is needed for the synthesis of what?
- Collagen
- Bile acids
- Catecholamines
- Carnitine
How is vitamin C involved in collagen synthesis?
- Essential for activating prolyl hydroxylase → promotes the formation of hydroxyproline → which is a key component of collagen
Zinc is a cofactor for which enzymes?
- Carbonic anhydrase
- Collagenase
- 5α reductase
Where is the main storage site for vitamin k?
The liver
Which fat soluble vitamin has the shortest half life?
Vitamin K
What is the primary action of vitamin K? How?
- Activate clotting factors II, VII, IX, and X
2. Facilitates carboxylation of glutamate residues by glutamate carboxylase
What binds to copper after absorption into intestinal mucosal cells?
Metallothionen
What is copper bound to for transport to the liver?
Albumin
Copper is transported from the liver to other sites via what?
Ceruloplasmin
What is the most important antioxidant in the body?
Vitamin E
How is RER calculated?
70 x kg ^ 3/4
What is the major antigen in IBD? (carb/protein/fat)
Protein
How is glucose trapped in cells?
Conversion to glucose-6-phosphate
*Only the liver, renal, and interstitial epithelium have phosphatase which can remove the phosphate and liberate glucose from the cell
When monglycerides and glycerol are absorbed into enterocytes, they are first reassembled into ______
Triglycerides
Triglycerides are packed into _____ for transport through the lyme, eventually ending up in the venous circulation
Chylomicrons
*Chylomicrons are 82% TG, 9% phospholipid, 3% cholesterol, 1% apoprotein B
Triglycerides are hydrolyzed by _____ on the capillary endothelium, releasing _____ and _____.
- Lipoprotein lipase
- FFA
- Glycerol
When FFAs are released into the blood they are carried primarily on ______
Albumin
How are FFA transported into the mitochondria?
Carnitine
