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98 Cards in this Set
- Front
- Back
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What are the two fatty acids that the body cannot produce itself?
Where are these naturally derived from? |
Linoleic acid
Linoenic acid Plant oils |
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Essential fatty acids _____ be synthesized because humans lack the enzymes to place _____ _____ at certain positions and msut therefore obtain them from diet.
What are these positions? |
Cannot
Double bonds Omega-3, Omega-6 |
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All fatty acids are building blocks of _____ and _____ and are therefore important in the synthesis of _____.
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Phospholipids
Glycolipids membranes |
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Cells derive energy from fatty acids through _____.
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Beta-oxidation
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What can be classified by the number of double bonds between carbon atoms in their fatty acid molecules?
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Fats
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What fats:
Contain no bonds between carbon atoms? Has one double bond between carbon atoms? Has multiple double bonds between carbon atoms? |
Saturated
Monounsaturated Polyunsaturated |
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Monounsaturated fatty acids are in the _____ form.
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CIS (same-side)
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What are the saturated fatty acids?
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Arachioic
Behenic Butyric Capric Caproic Caprylic Lauric Myristic Palmitic Stearic |
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What are the monounsaturated fatty acids?
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Erucic
Oleic Palmitoleic |
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What are the polyunsaturated fatty acids?
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Arachidonic
Linoleic Linolenic |
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The _____, which are tiny microdroplets emulsified by biles salts, travel to the _____ of the intestinal epithelial cells, which absorb the _____ _____.
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Micelles
Microvilli Fatty acids |
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The bile salts are _____, recycled in the _____, and secreted into the gut during subsequent _____ _____.
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Resorbed
Liver Digestive cycle |
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What are the two important actions of bile salts in the intestinal tract?
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1. Absorption of Fatty acids, monoglycerides, cholesterol, ect.
2. Detergent action which decreases surface tension and breaks up fat globules into smaller particles |
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Bile acids are usually _____ in amide linkage with amino acid _____ or _____.
What does this produce? |
Conjugated
Glycine Taurine Bile salts |
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The cholic acid conjugates with glycine and taurine are called _____ and _____.
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Glycocholate
Taurocholate |
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What is the only membrane phospholipid not derived from glycerol?
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Shingomyelin
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What are the usual membrane phospholipids which contain glycerol?
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Lecithin
Cerebroside Cardiolipin |
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What is the structure of phospholipids?
What is it similar to? |
Glycerol molecule attached to 2 fatty acids and a phosphate group
Similar to triglycerides |
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What are a group of phospholipids that upon hydrolysis yield 2 fatty acid molecules and a molecule each of glycerol, phosphoric acid, and choline?
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Lecithins
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Lecithins are water soluble _____ and _____ constituents.
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Emulsifiers
membrane |
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What are a group of phospholipids having hemostatic properties and found especially in the nervous tissue in the brain and spinal cord?
What do they resemble? |
Cephalins
Lecithins |
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How does cephalin differ from lecithin?
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Contains 2-ethanolamine or L-serine in the place of choline
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What are a group of phospholipids that are found especially in nerve tissue and yield _____, choline, a fatty acid, and phosphoric acid upon hydrolysis?
They are _____ constituents. |
Sphingomyelins
Shingosines Membrane |
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The neurological disturbances seen in _____ disease are associated with the accumulation in the CNS tissue of _____.
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Neimann-Pick
Sphingomyelin |
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What is the order of most dense to least dense in terms of lipoproteins?
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HDL - LDL - VLDL - Chylomicrons
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What is the lipoprotein that is the primary plasma carrier of cholesterol?
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LDL
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What are the micellar structures that transport lipids called?
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Lipoproteins
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Since lipids are much less dense than proteins, there is an _____ relationship between the lipid content and density.
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Inverse
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What is the protein component of a lipoprotein called?
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apolipoprotein
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What contains the most triglyceride and the least protein content, and transports primarily dietary triacylglycerols around the body?
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Chylomicrons
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What is more dense than chylomicrons and has a high content of triglycerides, and transports endogenous triacylglycerols to various tissues?
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VLDL's
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What are denser than VLDL's and less triglyceride and more protein content, has the highest content of cholesterol? These are the primary plasma carriers of cholesterol for delivery to all tissues.
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LDL's
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What are the most dense lipoprotein which has the lowest triglyceride and highest protein content? This transfers cholesterol as an acyl ester derivative from other tissues back to the liver.
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HDL's
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Lipoproteins are transported into cells by way of receptor-mediated _____.
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Endocytosis
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Plasma lipoproteins consisting of a large droplet of triacylglycerols that are stabilized by a coat of protein and phospholipid.
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Cylomicrons
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Remnants of chylomicrons, depleted of their _____, but still containing cholesterol, move through the bloodstream to the _____, where they are taken up, degraded into _____, and constituents _____.
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Triacylglycerols
Liver Lysosomes Recycled |
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Chylomicrons are the least dense lipoprotein because they have the _____ triacylglycerols and the _____ protein content.
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Most
Least |
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What lipoprotein is very rich in cholesterol and the major cholesterol carrier in the blood?
what is it derived from? |
LDL
VLDL |
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HDL particles are produced _____ in the liver.
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de novo
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Where are the specific binding sites for HDL?
LDL? |
Liver
Liver and extrahepatic tissues |
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What drug lowers blood cholesterol levels by inhibiting an enzyme which is the key regulatory enzyme in cholesterol biosynthesis?
What is the enzyme? |
Lovastatin
Inhibiting HMG CoA reductase |
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Where does ketone body synthesis from acetyl-CoA occur in the body?
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Hepatic mitochondria
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What are the compounds that are classified as ketone bodies in the liver?
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acetoacetate
3-hydroxybutyrate (beta) Acetone |
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Ketone body production is regulated primarily by availability of what?
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Acetyl-CoA
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What are the steps to making utilizing ketone bodies during times of starvation?
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Low glucose
Mobilization of Fatty acids Beta oxidation rate increase Increase Acetyl-CoA Increase Ketone bodies Ketones moved to peripheral tissues Ketones back to Acetyl-CoA Oxidized by Citric Acid Cycle (Krebs) |
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What is the first step in the formation of ketone bodies?
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Form Acetoacetyl-CoA in reverse thiolase step of beta-oxidation
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What is the second step in formation of ketone bodies?
What is this reaction catalyzed by? |
3rd molecule of acetyl-CaA condenses w/ acetoacetyl-CoA to form
3-hydroxy-3-methyglutaryl CoA (HMG CoA) HMG-CoA Synthase |
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What is the rate limiting step in the synthesis of ketone bodies and is present in significant quantities where?
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HMG-CoA synthase
Liver |
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What is the third step in the formation of Ketone bodies?
What is this reaction catalyzed by? What is produced? |
HMG-CoA cleaved to yield acetoacetate
HMG-CoA lyase One molecule of acetyl-CoA |
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What can the acetoacetate formed from the third step of the synthesis of ketone bodies?
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Can be reduced to form 3-hydroxybutyrate or spontaneously decarboxylated to form acetate
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What organs or muscle groups use ketone bodies particularly well?
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Heart, Skeletal muscles
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Where can ketone bodies get oxidized?
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Brain
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Why can the liver not use ketones itself as a fuel source?
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It can make the ketone bodies but it can't reconvert acetoacetate to acetoacetyl-CoA
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_____ is the major source of acetyl-CoA for fatty acid synthesis.
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Glucose
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Where does fatty acid synthesis occur primarily?
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Cytoplasm of the liver
Lactating mammary gland Lesser extent adipose tissue and kidney. |
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In the process of fatty acid synthesis glucose is first degraded to _____ by aerobic _____ in the cytoplasm.
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Pyruvate
Glycolysis |
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After aerobic glycolysis where is pyruvate transported?
What happens here? |
Into mitochondria
Dehydrogenase oxidatively decarboxylates pyruvate forming Acetyl-CoA |
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Acetyl-CoA serves as a substrate for _____ synthesis.
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Citrate
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Where is Citrate transported?
Where does fatty acid synthesis occur? What happens to citrate after transport? |
Cytoplasm
Cytoplasm Splits to generate cytoplasmic acetyl-CoA for fatty acid synthesis |
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What is the summary of fatty acid synthesis?
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Acetyl-CoA --> Malonyl-CoA --> Malonyl-ACP --> Acetyl-ACP --> Acetoacetyl-ACP --> Butyryl-ACP --> Fatty Acid
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The carboxylation of Acetyl-CoA to form malonyl-CoA is catalyzed by _____ _____.
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Acetyl-CoA carboxylase
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What is a three-carbon intermediate that participates in the biosynthesis of fatty acids but not in their breakdown?
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Malonyl-CoA
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What is involved in both fatty acid catabolism and synthesis?
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Coenzyme A
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What is the carrier substance that transports fatty acids to the liver in Fatty acid Catabolism?
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Carnitine
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Once inside the mitochondria, fatty acids are transferred from the carnitine to a CoA and _____ to acetyl-CoA. The acetyl-CoA molecules enter into the _____ _____ cycle to form _____ _____ and reducing equivalents _____ _____.
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Oxidized (Beta-oxidation)
Citric Acid Cycle (krebs cycle) Carbon Dioxide NADH, FADH2 |
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In the fatty acid synthesis what are reoxidized at the end by electron transport system and the energy released by said process used by the oxidative phosphorylation system to form _____?
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FADH2, NADH
ATP |
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fatty acids are the predominant source of ATP for levels that...
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Longer than one hour
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What is formed from acetyl-CoA, bicarbonate, and ATP and is a key intermediate in the synthesis of fatty acids?
What kind of reaction is this? |
Malonyl-CoA
Irreversible reaction (rate limiting) |
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Coenzyme A is a _____ _____ containing coenzyme that is involved in both fatty acid _____ and _____.
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Pantothenic Acid
Synthesis Catabolism |
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Acetyl-CoA is a common intermediate of the metabolism of not only Fatty acids but also _____ _____ and _____.
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Amino acids
Carbohydrates |
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What is a condition characterized by an abnormally elevated concentration of ketone bodies in the body tissues and fluids?
This is a complication found in what disease? |
Ketosis
Diabetes mellitus, starvation, fasting, and alcoholism |
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What are the characteristics of ketosis?
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Ketones in the Urine
Potassium loss in the Urine Fruity odor of acetone on the breath |
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What can ketosis lead to?
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Ketoacidosis (lowers pH)
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A _____ _____ can be caused by the buildup of ketone bodies. It is commonly fatal, unless appropriate therapy is instituted promptly.
What can be used to reverse this in a non-diabetic patient? |
Diabetic coma
Glucose |
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Fatty acid synthesis takes place in the _____ while fatty acid breakdown takes place in the _____.
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Cytosol
Mitochondria |
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The _____ of a fatty acid is a long hydrocarbon chain, making it _____. The _____ of a fatty acid is a carboxyl group which is _____.
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Tail, Hydrophobic
Head, Hydrophilic |
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What are the major lipids?
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triacylglycerols (most common)
phospholipids Steroids |
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What is a naturally occurring ester of three fatty acids and glycerol that is the chief constituent of fats and oils?
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Triglyceride
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What provides more than half the energy requirements of some organs, particularly the liver, heart and skeletal muscle?
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Triglycerides
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What are not membrane constituents like phospholipids and sterols?
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Triglycerides
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How much energy does triglycerides contain?
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Twice as much energy as carbohydrates (8000 kcal/kg)
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What do high levels of triglycerides in the bloodstream indicate?
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Atherosclerosis, and by extension heart disease and stroke
Pancreatitis is also a possibility |
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The negative impact of triglycerides is still lower systemically than _____.
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LDL-cholesterol
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Choline is considered a what?
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Essential nutrient
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Although humans can synthesize _____ in small amounts, it must be consumed in the diet to maintain health.
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Choline
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The majority of the body's choline is found in specialized fat molecules known as _____, the most common of which is called _____ or _____.
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Phospholipids
Phosphatidylcholine or Lecithin |
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Choline contributes to the proper structure and function of what?
How does it reside here? |
Cell membranes
Phosphatidylcholine |
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Choline is part of the _____ that makes up the myelin sheath, choline _____ nerve fibers and aids in the rapid conduction of _____ _____.
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Sphingomyelin
Insulates Electrical impulses |
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Choline is a precursor of _____, an osmolyte used in the _____ to control water balance.
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Betaine
Kidney |
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Choline functions in the _____ as a source of methyl groups required for lipoprotein formation and for the synthesis of _____ from _____.
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Liver
Methionine Homocysteine |
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Choline is necessary for the synthesis of _____, an important neurotransmitter involved in memory storage and muscle control.
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Acetylcholine
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Choline is an active component of _____ in the lung.
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Surfactant
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What can a deficiency of choline in the diet cause?
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Abnormalities in the metabolism of fats and can lead to fatty liver disease and eventually hepatic cirrhosis.
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The binding of glucagon to its receptor activates what?
What other hormone does this? |
Adenylate cyclase
Epinephrine |
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By activating the adenylate cyclase in the adipocyte of the plasma membrane what is raised?
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cAMP
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What enzyme is is active in phosphorylating and thereby activating hormone-sensitive _____ _____?
What does this do in turn? |
cAMP-dependent protein kinase
triacylglycerol lipase Initializes hydrolysis of ester linkages of triglycerides - forming free fatty acid and glycerol |
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_____ causes activation of a phosphorylase that dephosphorylates the hormone sensitive lipase and thereby diminishes lipolysis.
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Insulin
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What happens to the newly freed glycerol in Adenylate cyclase?
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Glycerol - phosphorylated (glycerol kinase) = glycerol-3-phosphate - oxidized (dihydroxyacetone phosphate) - converted (triose phosphate isomerase) = glyceraldehyde-3-phosphate - oxidized (glycolysis) = glyceraldehyde-3-phosphate
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