Metabolism- Exam 1
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- What are the three types of lipids?
- TG (95%), phospholipids, sterols (plant sterols, cholesterol)
- How many carbons make up SCFA?
- 4-8 C
- How many carbons make up MCFA?
- 10-14 C
- How many carbons make up LCFA?
- 16-20 C
- How many carbons are usually found in dairy products?
- 6-10 C
- How many carbons are present in most dietary FA?
- 16-18 C
- Cis TG
- H on the same side of double bond; U-like formation; most naturally occurring fatty acids
- Trans TG
-
H on the oppose sides of double bond; more linear; partially hydrogenated;
PUFA+hi pressure+H2 -->saturation
behave more like saturated FAs
lower fluidity - What is the formula for a monounsaturated fatty acid?
- C(n)H(2n-2)O2
- polyunsaturated fatty acids
- will be oxidized with oxygen at their double bond sites; require anti-oxidants to maintain their structures
- myristic acid
- 14:0
- palmitic acid
- 16:0
- stearic acid
- 18:0
- palmitoleic acid
- 16:1 w-7
- oleic acid
- 18:1 w-9
- linoleic acid
- 18:2 w-6
- arachidonic acid
- 20:4 w-6
- linolenic acid
- 18:3 w-3
- eicosapentanoic acid (EPA)
- 20:5 w-3
- docosahexaenoic acid (DHA)
- 22:6 w-3
- Plant oils are a good source of alpha lenolenic acid or linoleic acid?
- linoleic
- What plant oils contain a significant amount of alpha-linolenic acid?
- canola oil and soybean oil
- What is the best source of w-3 fatty acids?
- cold water fish
- What is caused by a deficiency of linoleic acid?
- (much rarer) ...neurological damage, including blurred vision
- EFAs are precursors to what?
- prostaglandins, prostacyclins, thromboxanes, leukotrienes
- Cholesterol is a precursor of?
- bile acids, steroid hormones, adrenal hormones (cortisol), vitamin D
- What is lecithin?
- phospholipid
- lingual lipase
- important largely for neonates in lipid digestion; acts on milkfats (preemulsified fats)
- How does the stomach contribute to lipid digestion?
- not much; churning creates a course lipid emulsion; fat slows the release of food from the stomach (satiation)
- What is the small intestine's role in lipid digestion?
- performs 90% of all lipid digestion; primarily performes hydrolysis and deesterification; also mixes bile salts to convert coarse emulsion into micelles
- Pancreatic lipase is inhibited by __________________, and enhanced by ______ and ________.
- bile salts; Calcium; Colipase
- Phospholipase A2
- lecithinase; acts at C1, 2 position of PL
- cholesterol esterase
-
removes FA at low pH - lumen;
adds FA at higher pH - mucosa - What is the circulatory route for short chain fatty acids?
- portal vein to the liver fro processing
- What is the circulatory route for long chain fatty acids/
- TG assembly --> chylomicron formation --> lymph --> heart --> general circulation (peripheral tissues) --> liver
- What are the mediators for lipid digestion in the adipose and muscle?
- apolipoprotein CII + lipoprotein lipase
- What are teh mediators for lipid digestion in the liver?
- apolipoprotein E + apolipoprotein E receptor
- Hormone sensitive lipase
-
releases FFA from adipocte into serum
Stimulation: epinephrine, glucagon
Inhibition: insulin, prostaglandins - Lipoprotein lipase
-
release FFA from CM at adipocyte and muscle surface;
for uptake and use as energy (muscle) or storage (adipocyte)
Activation: lipoprotein CII, insulin - Phosphatidate phosphatase
-
in all cells, synthesizes TAG from glycerol-P;
activation: steroid hormone - What is the only cofactor that can add CO2?
- biotin
- How is acetyl CoA carbosylase regulated?
-
increased by citrate (substrate);
decreased by palmitoyl-CoA (end product) - Resins, colestipol, cholestyramine
- block resorption of bile acids; upregulate LDL Rc, HMG CoA reductase; lower plasma LDL levels
- Mevinolin (levostatin)
- inhibits HMG CoA reductase activity