Week 1 Flashcards
What is an alternative name for vitamin B1? What is the active form?
Thiamine
Thiamine pyrophosphate
What is the function of vitamin B1?
What can result from a vitamin B1 deficiency?
What is an alternative name for vitamin B2? What is the active form?
Riboflavin
FMN, FAD
What is the function of vitamin B2?
Electron transfer
Cofactor for some dehydrogenase enzymes
What can result from vitamin B2 deficiency?
What is an alternative name for vitamin B3? What is the active form?
Niacin, nicotinic acid
NAD+, NADP+
What is the function of vitamin B3?
What can result from a deficiency of vitamin B3
What toxicities can result from vitamin B3?
What is an alternative name for vitamin B5? What is the active form?
Pantothenic acid
Coenzyme A
What is the function of vitamin B5?
How common is a vitamin B5 deficiency?
Rare
Which water-soluble vitamin can be synthesized from tryptophan but not always in sufficient amounts?
Vitamin B3
What is an alternative name for vitamin B6? What is the active form?
Pyridoxine, pyridoxamine, pyridoxal
Pyridoxal phosphate
What is the function of vitamin B6?
A coenzyme for many enzymes, especially those involved with amino acid metabolism
What can cause vitamin B6 deficiency? What may result?
What can result from vitamin B6 toxicity?
Sensory neuropathy can occur at high doses
What is an alternative name for vitamin B7? What is the active form?
Biotin
Enzyme-bound biotin
What is the function of vitamin B7?
What is the result of vitamin B7 deficiency? How is it caused?
What is an alternative name for vitamin B9? What is the active form?
Folic acid
Tetrahydrofolate
What is the function of vitamin B9?
What can result from vitamin B9 deficiency?
Megaloblastic anemia
Neural tube defects
Excess amounts of what vitamin can mask a B12 deficiency?
vitamin B9
What is an alternative name for vitamin B12? What is the active form?
Cobalamin
Methycobalamin, deoxyadenosylcobalamin
What is the function of vitamin B12?
What is the result of vitamin B12 deficiency?
What is an alternative name for vitamin C? What is the active form?
Ascorbic acid (both)
What is the function of vitamin C?
What is the result of vitamin C deficiency?
Which vitamins are fat-soluble?
Vitamins A, D, E, and K
What are alternative names for vitamin A? What is the active form?
Retinol, Retinal, Retinoic acid, B-carotene (precursor to vitamin A)
Retinol, Retinal and Retinoic acid are all active forms
What is the function of vitamin A?
What can result from vitamin A deficiency?
What can result from vitamin A toxicity?
What are the alternative names for vitamin D?
What is the active form of vitamin D?
What is the function of vitamin D?
What can result from vitamin D deficiency?
What can result from vitamin D toxicity?
Is vitamin D a true vitamin?
No, it can be synthesized in skin from cholesterol precursors
What is an alternative name for vitamin E? What is the active form?
a-tocopherol
Several tocopherol derivatives
What is the function of vitamin E?
fat-soluble anti-oxidant
What can result from vitamin E deficiency?
What can result from vitamin E toxicity?
What are alternative names for vitamin E? What are the active forms
What is the function of vitamin K?
What can result from vitamin K deficiency?
What can result from vitamin K toxicity?
Which macrominerals are generally underconsumed in the USA?
Magnesium and Potassium
What is the main function of calcium?
What is the main function of chloride?
What is the main function of magnesium?
What is the main function of phosphorous?
What is the main function of potassium?
What is the main function of sodium?
Refeeding syndrome can cause temporary deficiencies in which 3 macrominerals?
Magnesium
Phosphorous
Potassium
What is the main function of copper?
What is the main function of fluoride?
What is the main function of iron?
What is the main function of manganese?
What is the main function of zinc?
Which 3 minerals are known as ultratrace minerals?
Iodine
Molybdenum
Selenium
What is the function of iodine?
What is the role of the FDA in regulating dietary supplements?
Monitor reported adverse events and periodically inspect manufacturing facilities
Which lipoproteins contain principally ApoA and are referred to as alpha lipoproteins?
Which lipoproteins contain principally ApoB and are referred to as beta lipoproteins?
Alernative splicing of ApoA or ApoB produces two different but overlapping proteins?
ApoB
ApoB-48 is found in what liproteins? Where is it synthesized?
Chylomicrons
Intestines
ApoB-100 is found in what lipoproteins? Where is it synthesized?
LDL, IDL and VLDL
Liver
What are the three main transport pathways for lipids?
What protein assists with packaging of TAG, Cholesterol esters and ApoB-48 into chylomicrons in enterocytes of the small intestine?
What two proteins are picked up by nascent chylomicrons from HDL in order to become a mature chylomicron?
ApoCII and ApoE
ApoCII is a cofactor for which enzyme?
Lipoprotein lipase (LPL)
What is the function of LPL?
To break down the TAG in chylomicrons into FA
What occurs after ApoE on a chylomicron remnant is united with the receptor on a hepatocyte?
Endocytosis of the chylomicron
TAG, ApoB-100, and FA are packed into what molecule by MTP in hepatocytes?
VLDL
After interacting with LPL, VLDL is converted to what?
IDL
After IDL is endocytosed by hepatocytes, what is exocytosed?
LDL
ApoA is synthesized in what cell types?
Enterocytes and Hepatocytes
Freshly synthesized HDL is referred to with what designation?
Nascent (lipid-poor HDL)
Pre-HDL is converted to mature HDL as cholesterol is esterified with the help of what enzyme?
Lecithin-cholesterol acyltransferase (LCT)
What enzyme is the RLS in cholesterol biosynthesis?
HMG-CoA reductase
What is a SREBP?
Sterol-response element binding protein is a transcrition factor that regulates cholesterol synthesis genes
When a cell is low in cholesterol what happens to SREBP activity?
It goes up, signaling for increased HMG-CoA reductase activity
Familial or inherited hyperlipidemia is referred to as what type?
Primary hyperlipidemia
Acquired hyperlipidemia via other diseases or medications is referred to as what type?
Secondary hyperlipidemia
What are xanthomas?
Deposits of fat under the skin or on tendons
What is the proper name for xanthomas around the eyes?
Xanthelasma
What are two major complications of hyperlipidemia in the heart and liver?
Fatty liver disease and ASCVD
Define Type 1 hyperlipidemia:
Elevation of chylomicrons (often due to deficiency of ApoC2 or LPL)
Eruptive xanthomas and acute pancreatitis are best associated with what type of hyperlipidemia?
Type 1 hyperlipidemia
Define Type 2 hyperlipidemia:
A dominant condition characterized by elevation of LDL (Type A) or LDL and VLDL (Type B)
An absent LDL receptor leading to signaling resulting in elevated LDL or VLDL would best characterize what type of hyperlipidemia?
Type 2 hyperlipidemia
Define Type 3 hyperlipidemia
A rare recessive disorder also called familial dysbetalipoproteinemia (defective ApoE)
Define Type 4 hyperlipidemia
Familial hypertriglyceridemia (increased VLDL production by liver and chylomicron circulation with decreased LPL activity)
What disease is the most common cause of acquired hyperlipidemia?
Diabetes mellitus
What are additional diseases besides diabetes that can cause hyperlipidemia?
Hypothyroidism and nephrotic syndrome
What is the most common cause of hypolipidemia?
Abetalipoproteinemia (autosomal recessive defect in MTP protein, and deficiency of ApoB-48 and ApoB-100)
An intestinal biopsy showing intestinal cells containing excess fat is diagnostic of what pathology (in context of lipid disorders)?
Hypolipidemia
Thiazide diuretics can contribute to what type of lipid disorders?
Hyperlipidemia
For a patient who had previously experienced an MI, what is the goal number under which to keep their LDL?
70 mg/dL
An example of a type IIa Frederickson class hyperlipidemia would be what notable disease? What is its inheritance pattern?
Familial hypercholesterolemia
Autosomal dominant
What is the name of the displayed abnormality?
Corneal arcus
What is the name of the displayed abnormality?
Xanthelasma
What is the name of the displayed abnormality?
Tendinous xanthoma
What is the most likely diagnosis for a patient presenting with corneal arcus, xanthelasma, tendinous xanthomas and an elevated total cholesterol and LDL level?
Familial hypercholesterolemia (Type IIa)
Though 80-90% of cases of familial hypercholesterolemia are due to LDL receptor mutations, what are two other molecules that may be mutated in rarer forms?
ApoB100
PSCSK9
A patient with homozygous familial hypercholesterolemia, what additional treatment besides statins may be necessary?
1) A monoclonal Ab like Evinacumab (IV), to inhibit LPL and hepatic endothelial lipase
2) Lomitapide (PO), which can inhibit MTP (which transfers TG onto ApoB during VLDL synthesis)
3) LDL apheresis every 1-2 weeks
4) Liver transplant to introduce functional hepatic LDL receptors
Why might a patient presenting with triglycerides of >1000mg/dL present with abdominal or flank pain?
With a concentration >1000mg/dL, chylomicrons will be present and may impair blood flow to pancreas, causing ischemia which can contribute to injury/inflammation
What are three classes of secondary etiologies for hypertriglyceridemia?
PPC
1) Physiological
2) Pharmaceutical
3) Conditions (other medical)
What is an acronym for pharmacologic causes of hypertriglyceridemia?
B-GATE
Beta-blockers
Gluccocorticoids
Alcohol
Thiazide diuretics
Estrogen-cont. products