Biochem: Lipids Flashcards
What is the difference between saturated, monounsaturated and polyunsaturated fatty acids?
Saturated - no double bonds
Mono - one double bond
Poly - many double bonds
T/F: Prostaglandins are made from polyunsaturated fatty acids.
True
T/F: Triglycerides are an important part of the cell membrane.
False
Not in the cell membrane
Which membrane phospholipid is converted to arachidonic acid? By which enzyme?
Phosphatidyl inositol via phospholipase A2 (PLA2)
What types of lipids are derived from arachidonic acid?
Eicosanoids (leukotrienes, prostaglandins, thromboxanes, etc.)
________ inhibit PLA2 and therefor the release of arachidonic acid.
Corticosteroids
__________ are found in nerve cell membranes and are an important part of the myelin sheath.
Sphingomyelins
An excess accumulation of sphingomyelins causes what disease?
Niemann-Pick disease
________ is the precursor to adrenal cortex hormones (salt, sugar, sex).
Cholesterol
Which enzyme will convert arachidonic acid to prostaglandins, thromboxanes, and prostacyclins (proinflammatory)?
COX enzyme
Which enzyme will convert arachidonic acid into leukotrienes?
LOX
*allergic reactions and asthma
What are the four essential fatty acids?
Linolenic acid (omega 3) Linoleic (omega 6) Oleic acid (omega 9) Arachidonic acid
T/F: LInoleic acid is proinflammatory and polyunsaturated.
True
________ is released by the pancreas into the duodenum to break down emulsified triglycerides.
Pancreatic lipase
What is the primary result of pancreatic lipase digestion?
Mixed micelle
Biles salts, free FAs, and monosaccharides
T/F: HDL levels should be higher than 100.
False
HDL > 50
LDL < 100
What should triglyceride levels stay lower than?
150
T/F: Total cholesterol should stay under 200.
True
How is LDL transported into target tissue?
Cell receptor-mediated endocytosis
________ deficiency can cause abnormal fat metabolism and can lead to fatty liver disease and hepatic cirrhosis.
Choline
Why is HDL beneficial?
It takes cholesterol from tissues back to the liver
Xanthelasma is yellow deposit of cholesterol under the skin. What is the number one cause of this?
Aging
Not high cholesterol
What are the three ultimate outputs of beta oxidation?
NADH, FADH, Acetyl-CoA
_______ is the breakdown of fatty acids.
beta oxidation
Beta oxidation is in the mitochondrial matrix. How do fatty acids enter the mitochondrial matrix?
Carnitine-mediated enzyme shuttle
Which ketone body would result in a fruity breath?
Acetone (not used as energy)
What are the three types of ketone bodies?
- Acetoacetate
- Beta-hydroxybutyrate
- Acetone
Where in the cell does fatty acid synthesis occur?
Cytosol
How does acetyl-CoA get to the cytosol for fatty acid synthesis?
Citrate-malate shuttle
T/F: Omega 3s (lenolenic acids) are anti-inflammatory.
True
Includes EPA and DHA
How many calories per gram do you get for the three macromolecules?
Proteins - 4
Carbs - 4
Lipids - 9
Which of the vitamins are fat soluble?
DEAK
Which fat soluble vitamin is the most toxic?
Vitamin D
DANGEROUS
Where is the active form of vitamin D produced?
Kidneys
Deficiency in vitamin D will lead to which two diseases?
Ricketts in children
Osteomalacia in adults
Excess vitamin D can lead to sarcoidosis. Who is most likely to get this disease?
Middle aged African American females
What are the main vitamins and minerals that make up antioxidants?
ACE + zinc + glutathione
E is a big one
What is the precursor for vitamin A?
Beta CAROTene
T/F: Vitamin A plays a large role in enamel formation.
True
Also eyes, and epithelium
Warfarin is an antagonist of which vitamin?
Vitamin K
Vitamin K induces clotting
Deficiency of which vitamin is seen often in alcoholics?
Vitamin B1 (thiamine) and B12
A deficiency in vitamin B1 (thiamine) can lead to which disease?
Wernicke-Korsakoff syndrome and Beriberi
Intrinsic factor is needed to absorb vitamin B12. What cells release intrinsic factor?
Parietal cells in stomach
Which disorder is caused by decreased intrinsic factor leading to B12 deficiency?
Pernicious anemia
very common
Which vitamin is a coenzyme for the hydroxylation of proline and lysine (collagen synthesis)?
Vitamin C
What is the number one vitamin deficiency in the U.S.?
Folic acid
What is the function of folic acid?
Synthesis of purines and thymidine
Why would a pregnant woman take folic acid supplements?
Prevent spina bifida
Megaloblastic anemia involves deficiency in which vitamin?
Folic acid
Which disease involves large accumulations of copper?
Wilson’s disease (Hepatolenticular degeneration)
Which mineral inhibits bacterial enolase?
fluoride
Which mineral is critical for thyroid function?
Iodine
Deficiency = cretinism (kids) or myxedema (adults)
T/F: Hyperthyroidism will result in low T3.
False
High T3 and T4, low TSH
A deficiency in iron will cause what type of anemia?
Microcytic
T/F: Iron must be in its reduced (ferrous) state to be used in hemoglobin.
True
T/F: Zinc is required for DNA synthesis.
True
______ is a cofactor for producing carbonic anhydrase.
Zinc
*carbonic anhydrase produces bicarbonate