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170 Cards in this Set
- Front
- Back
What are the primary functions of lipids?
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-Energy
-Insulation & protection -Temperature regulation -Protects organs -Cell membranes |
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What do the structural functions of lipids include?
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The phospholipid bilayer made of cholesterol. It keeps the shape of the organelle.
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On the surface of the cells, ___________ serve as markers for cell recognition.
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Glycolipids
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In what state do you go under gluconeogenesis?
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Fasted state- Making of glucose because you need energy. For example, after sleeping (fasted state) and STILL not eating yet! Going on throughout your day without eating- brain and RBC need glucose.
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Glycolipids are made up of what?
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Lipids with a carbohydrate attached
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Which carbohydrate pathway occurs primarily in the liver?
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Gluconeogenesis:
Makes sense because liver is providing source of glucose from other compounds including GLYCEROL, LACTATE, or AMINO ACIDS. |
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Where else can gluconeogenesis occur in small amounts?
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The kidneys
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Adding fiber to the diet increases ___________ __________.
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Fecal bulk
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How does fiber play a role in preventing colon cancer? Four ways: 1 & 2 are about colon wall; 3 & 4 are about bile acids
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1. Decreases carcinogen formation in lumen of intestines (by pushing things through).
2. Shortens transit time (speeding it up)- decrease time to create or absorb toxins into tissue. 3. Fibers absorb primary bile acids which exert protective effect (b/c secondary bile acids are more cancer-causing). 4. Some fiber undergoes fermentation to create short chain fatty acids; this changes pH and reduces conversion to secondary bile acids. |
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"Transit time" refers to what?
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Time it takes to go from the start of digestion to end.
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If you reduce transit time, you're actually doing what?
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Decreasing the time to absorb toxins in the body.
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Lipids assist with the regulation of metabolism through what?
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Glycolipids and cell signaling
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What are the three main functions of lipids?
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Structure, energy, and regulation of metabolism.
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Lipids can be classified as what?
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Simple lipids or compound lipids
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Simple lipids include what three sub-categories?
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1. Fatty acids
2. Triacylglycerols (TAG), diacylglycerols (DAG), & monoacyglycerols (MAG) 3. Waxes |
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Compound lipids include what three sub-categories?
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1. Phospholipids
2. Glycolipids 3. Lipoproteins |
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Lipid classifications are determined by what?
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Chain length and degree of saturation.
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What does the degree of saturation pertain to?
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The number of hydrogens surrounding the carbon. If it is fully surrounded it is considered "saturated".
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If there is 1 double bond, it is ___________.
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Monounsaturated
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If there are 2 or more double bonds, it is __________.
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Polyunsaturated
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Why does the chain length become important?
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Short/medium chains and long chains are transported by different systems.
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Short and medium chains are transported through what system?
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Vascular system!
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Long chains are transported through what system?
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Lymphatic system!
(Hint: L & L) |
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***Saturated fats are found in plant or animal products?
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Animal; but also palm and coconut oils
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Unsaturated fats are found in plant or animal products?
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Plant
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Triacylglycerols are made up of what?
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3-carbon backbone with ester bonds and 3 fatty acids
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In the nutrition realm, what are "short-lived"? TAGs, DAGs, or MAGs?
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DAGs and MAGs. TAGs are the most common by far!
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When H2O is formed, it is called ____________.
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Metabolic water
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When H2O is formed, what two things are being joined together in ester bonds?
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Glycosidic bonds and fatty acids.
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95 percent of lipids are ____________.
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Triglycerides
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Lipoproteins are involved with the __________ of lipids.
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Transport
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Which type of bile acid is more likely to cause tumors?
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Secondary bile acids
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__________ are also known as esters of fatty acids with higher alcohols.
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Waxes
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Waxes are classified as what two things?
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1. Sterol esters (cholesterol-fatty acid esters)
2. Nonsterol esters (Vitamin A esters, and so on) |
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What phospholipid is involved in cell signaling?
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Plasmalogens
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What are the sources of arachidonic acid?
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Linoleic converted to arachidonic acid
Cell membranes Diet (Animal products) |
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Disaccharides are broken down where?
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Lumen of the small intestine
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What are the 9 essential amino acids?
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PVT TM HILL:
Phenylalanine Valine Threonine Tryptophan Methionine Histidine Isoleucine Leucine Lysine |
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Chylomicrons are transported by which system?
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Lymphatic
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Lipoproteins are made up of what four components?
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Triglycerides
Cholesterol Protein Phospholipids |
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T or F?
Adipose tissue is the only tissue that can't use glycerol. |
TRUE
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Glucose serves what two purposes?
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1. Making fatty acids to put on triglycerides
2. 3 carbon backbone (glycerol) |
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Short and medium chain fatty acids are bound to what?
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Albumin
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In the FED state what occurs?
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Insulin levels go up
Enzyme activity increases |
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In the fasted state what occurs?
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Increase in ephinephrine, cortisol, and glucagon
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T or F?
Insulin's effect on adipose LDL is faster/more significant than on muscle LDL. |
TRUE
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T or F?
An increase in hormones increases activity of Hormone Sensitive Lipase. |
TRUE
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According to Dr. M, how many ATP are yielded each turn of beta oxidation?
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5 ATP
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What are the four key players of fat synthesis?
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Acetyl CoA
Malonyl CoA Condensing enzyme Carrier protein |
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Why is acetyl CoA the starting point of fat synthesis?
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Because ATP determines whether or not acetyl CoA goes to the TCA cycle or fat synthesis.
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What are the five conditionally indispensable amino acids?
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Arginine
Cysteine Glutamine Proline Tyrosine |
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What determines protein quality (3 things)?
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-The essential amino acid content
-Digestibility -Evaluation of protein quality |
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The evaluation of protein quality includes what?
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-AA chemical score
-Protein Efficiency Ratio -Biological Value -Net Protein Utilization -Nitrogen Balance |
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Under the Biological Value, which food has a value of 100?
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Egg whites!
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DRI for fat intake (% and grams)?
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20-35% of kcals; or ~45-75 grams
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DRI for saturated fat?
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<10%
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DRI for monounsaturated and polyunsaturated fats?
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~10% for each!
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AHA for trans fat?
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<1% of total kcals
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Cholesterol intake recommendation? What is it currently?
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Less than 300 mg/day!
Currently: 400-500 mg/day |
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What are the physiological functions of protein?
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-Structural basis of muscle tissue
-Major components of most enzymes -Source of energy (LEAST amount) |
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Chemistry of protein- What makes up protein?
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Carbon, hydrogen, oxygen, nitrogen, & sulfur
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What are the two functional groups of protein?
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Amino group (NH2)
Carboxylic/Acidic (COOH) |
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Carnitine is made up of _________ and ____________.
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The AA's lysine and methionine.
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All amino acids are made up of what?
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Amino group
Acid group Hydrogen attached "R" group or side chain |
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How many amino acids carry out all functions in the body?
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About 20!
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2 or more amino acids linked together create what?
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A dipeptide or polypeptide
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T or F?
Protein in in both plant and animal sources. |
TRUE
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A dipeptide has how many of amino acid? How many bonds?
What about a tripeptide? |
DI- 2 AA's; 1 bond
TRI- 3 AA's; 2 bonds |
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How many amino acids make up a polypeptide?
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50-100
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How many amino acids make up a protein?
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Over 100!
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What is produced with two amino acids join to make a dipeptide?
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Metabolic water
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When in the body is metabolic water formed?
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1. AA + AA = dipeptide
2. Glycosidic bonds 3. Fat and ester bonds |
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What makes a protein "incomplete"?
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If it is deficient of 1 or more essential amino acids.
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Current fat intake?
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34% of kcals; 12% from saturated fat!
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Beta oxidation occurs where?
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Mitochondria (lose 2 carbons per turn)
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Fat synthesis occurs where?
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Cytosol (gain 2 carbons per turn)
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Amino acids in the liver are used for what?
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Precursor (acetyl CoA) to make fat
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LDL is made where and from what?
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In the blood, from VLDL
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HDL is rich in what? Where is it made?
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HDL is rich in protein; Made in the liver and small intestine
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Where are chylomicrons formed?
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The small intestine
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What is the responsibility of the ER in lipid digestion?
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To repackage the long-chain fatty acids
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What is the enzyme responsible for adding CoA back to the fatty acid?
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Acyl CoA synthase
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Triglycerides can be broken down with bile and lipase into what?
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Diglycerides, monoglycerides, free fatty acids, and glycerol
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DG, MG, FFA, cholesterol, lysopic**, and bile all get packaged into the __________ to be transported.
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Micelle
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Premenopausal women convert alpha-lenoleic to EPA at a much higher rate than mean due to what?
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Estrogen!
(23% versus 9%) |
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Eicosanoids are ___________-like compounds.
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hormone
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Eicosanoids function as hormones and are stored where?
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The cell membranes until needed.
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What do eicosanoids help us do?
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Help us respond to changes in homeostasis in the body
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Linoleic acid is also called _________.
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Omega-6
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What is linoleic/omega-6 overall effect on the body?
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Pro-inflammatory!
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Where do we get arachindonate acid from?
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Linoleic acid, membrane phospholipid, and diet
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Omega-3's have what overall effect on the body?
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Anti-inflammatory!
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Arachindonate acid can make which eicosanoids?
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Group 2- Prostanoids, Leukotrienes, and Lipoxins
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Groups 1 & 2 tend to be _____________.
Group 3 tends to be _____________. |
Group 1 & 2 = Pro-inflammatory
Group 3 = Anti-inflammatory |
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Lipooxygenase enzymes make what?
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Leukotrienes
Lipoxins |
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Cyclooxygenase enzyme make what?
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Prostaglandins
Thromboxomes |
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Omega-3's can be classified as what two things?
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Alpha-lenoleic and EPA/DHA
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Alpha-lenoleic omega-3's are found in what?
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Plants! Such as walnuts, flax, soybeans, soybean oil, and canola oil.
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EPA/DHA omega-3's are found in what?
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Animal products! FISH
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What are considered to be the simplest lipids?
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Fatty acids!
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What is the structure of fatty acids (3 things)?
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1. Straight hydrocarbon chain
2. Polar group 3. Nonpolar group |
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One turn of the TCA cycle yields how many ATP?
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12 ATP
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What are the four fatty acid derivatives?
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Prostaglandins
Thromboxanes Leukotrienes Lipoxins |
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Bicarbonate increase the activity of what?
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Lipase
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Where is acetyl CoA generated?
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Mitochondria
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Where does fat synthesis occur?
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Cytosol
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What enzyme drives the reaction of OAA to citrate (beginning of TCA cycle)?
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Citrate synthase
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In order to cross from mitochondria to cytosol, OAA and acetyl CoA must create what?
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Citrate (only way acetyl CoA can "cross")
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Both fat synthesis and beta-oxidation require how many ATP to begin?
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2 ATP
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Acetyl CoA has how many carbons?
What is it linked to in step 3 of fat synthesis? |
2; Condensing enzyme
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Malonyl CoA has how many carbons?
What is it linked to in step 3 of fat synthesis? |
3; ACP (acyl carrier protein)
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Fatty acid synthesis requires _________ to supply reducing equivalents.
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NADPH
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Generate NADPH2 from the ___________________ for fat synthesis.
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HMP shunt
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Which reducing equivalent is used in fat synthesis (Different than beta oxidation)?
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NADPH2
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Which reducing equivalents are used in beta oxidation?
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FAD and NAD+ (which generate FADH & NADH2)
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What compounds are precursors for glyconeogenesis?
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Glycerol, Lactate, Pyruvate, and Amino Acids
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What are the three key steps in gluconeogenesis that cannot be reversed (Irreversible reactions)?
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PEP to pyruvate, FBP to F6P, and G6P to glucose
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What are the four key enzymes in gluconeogenesis (to reverse the irreversible reactions)?
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1. Pyruvate carboxylase
2. PEP carboxykinase 3. Fructose 1,6 bis phosphate 4. Glucose 6 phosphate |
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During gluconeogenesis, glycerol can become what?
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DHAP
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What is the compound that can cross over the mitochondrian wall in gluconeogenesis?
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Malate (OAA and all TCA amino acids must convert to malate to cross)
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The complete hydrolysis of triacylglycerols yields what?
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Glycerol and three fatty acids
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The activation of a fatty acid by coenzyme A involves ATP being hydrolyzed to _________. This is equivalent to using how many ATP?
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Hydrolyzed to AMP. Equivalent of using 2 ATP.
(Essentially, 2 ATP are used to activate!) |
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One turn of the TCA cycle yields 12 ATP, but there are two pyruvate, which means what?
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The two pyruvate means there will be 24 ATP in total!
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One acetyl CoA is responsible for how many ATP?
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12!
That's why you multiply the number of acetyl CoA's (pair of C's) by 12 to get the number of ATP in total for TCA cycle. |
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Oxaloacetate to PEP in gluconeogenesis involves what key enzyme?
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PEP carboxykinase
(THINK going to PEP and must remove a carbon) |
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Pyruvate to Oxaloacetate in gluconeogenesis involves what key enzyme?
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Pyruvate carboxylase
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FBP to F6P in gluconeogenesis involves what key enzyme?
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Fructose 1,6 bis phosphatase (opposite direction would be PFK!)
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G6P to Glucose in gluconeogenesis involves what key enzyme?
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Glucose 6 phosphatase
(Free glucose can only occur in the liver- NOT muscle!) |
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In the PEP ---> pyruvate irreversible reaction- In order to reverse it, ________ is the only thing that can serve to get pyruvate back to PEP.
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Oxaloacetate (OAA)!!!
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There is no enzyme to get us BACK from pyruvate to PEP. You have to go back through the ___________ to get there!
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Mitochondria
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What are examples of dietary fibers? Functional fibers?
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Most serve BOTH, except hemicellulose!
*Hemicellulose is only dietary. |
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Where is the majority of fiber found?
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Plant cell wall (95% of dietary fibers!)
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Difference between dietary fibers and functional fibers?
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Dietary fibers are unprocessed/natural.
Functional fibers are processed or extracted. |
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Where are pectins found?
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Jellies, jams!
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Where are gums found?
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Stabilizing agents and thickeners!
Ex: Ice creams |
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What is inulin?
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Under FRUCTANS! Way that some fiber gets into products.
*In yogurts- inulin is listed. |
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"Metamusal" is what type of powder?
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Psyllium powder (from the husk of psyllium seeds)
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What is the difference between soluble and insoluble fibers? And examples.
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Soluble fibers can be dissolve in water.
*EX: Oats, barley, legumes Insoluble fibers do NOT dissolve in hot water. *EX: Whole-grain products, nuts, seed, MOST VEGETABLES |
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Generally, vegetable and most grain products contain more _________ fibers than __________ fibers.
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More insoluble fibers than soluble fibers.
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Fiber can bind directly to __________ in the gut.
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Bile
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How does fiber lower serum cholesterol?
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Fiber binds directly to bile in the gut. Bile contains cholesterol. More fiber means that the cholesterol is carried out of the body, and the body gets more cholesterol from the blood into the LIVER to make more bile ---> LOWERS serum cholesterol.
*Also, shift bile acid pool from colic acid to chenodeoxycholic acid ---> inhibits enzyme HMGCoA reductase, which therefore reduces synthesis of cholesterol. *Generates short-chain fatty acids, somehow hepatic synthesis of cholesterol is reduced. |
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How do fermentable fibers act as "prebiotics"?
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Simply by promoting the growth of friendly bacteria.
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What is the recommended fiber intake for men and women between ages 19 and 50?
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Men: 38 grams
Women: 25 grams |
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For MOST of the reactions in the TCA cycle, the enzyme used will have the name of the substrate _________ as part of the name!
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The substrate BEFORE!
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Anytime NADH2 or FADH2 is generated, where are those reducing equivalents headed?
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The Electron Transport Chain!
FADH makes 2 ATP; NADH makes 3 ATP |
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In the TCA cycle, substrate level phosphorylation occurs where?
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The step from Succinyl CoA to Succinate!
*CoA is removed *GTP is generated from GDP (producing 1 ATP) |
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Removing CoA gives enough energy to phosphorylate GTP from GDP (when inorganic phosphate is added), which is a ____________ phosphorylation.
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Substrate-level
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1 GTP is equivalent to how many ATP?
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1 ATP
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In the TCA cycle, when the first de-carboxylic reaction occurs, remember two things:
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1. There's another de-carboxylic reaction right after it.
2. Both involve dehydrogenase enzymes in which NAD is being reduced to NADH2. |
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Why are there 24 ATP generated in the TCA cycle?
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Because there are 2 pyruvate coming in from one glucose!
One turn of the TCA cycle produced 12 ATP. |
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When we number carbons, we number them from the _____ end.
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Acid end!
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When we count the double bonds (to identify which omega fatty acid), we count from the ______ end.
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Methyl end
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The first double bond in a fatty acid structure refers to what?
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The name of the structure.
Ex: Omega-6 has a double bond at the 6th carbon from the methyl end. |
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No double bonds means the fatty acid is ________.
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Saturated; Completely surrounding by hydrogens
|
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Natural state of unsaturated fatty acids is in the cis or trans state?
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Cis
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Simple rearrangement by partially hydrogenating the fatty acids and relocating the hydrogens to opposite of each other creates what?
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Trans fat! And "trans" configuration.
|
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Naturally found trans fat is in small amounts in what?
|
Dairy products and meat
|
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Another name for lecithin is what?
|
"Phosphatidyl choline"
*Literally consists of glycerol, phosphate, and choline. |
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Triglycerides can be simple or mixed.
Simple triglycerides mean that all fatty acids are _______. Mixed triglycerides mean that all fatty acids are ______. |
Simple- The same!
Mixed- Different (C1 and C3 are saturated; C2 unsaturated). |
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Phospholipids primary function is involved in cell membrane structure; However, lecithin (or phosphatidyl choline) is ALSO involved in ______________.
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Lipid digestion!
|
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What are the three starting components of lipid digestion?
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Triglycerides
Cholesterol esters Phospholipid |
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What are the components that help BREAK DOWN lipid components?
|
Lipase (Bicarbonate increases activity!)
Bile (emulsifying; from the gallbladder) CCK (I cells of small intestine) |
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Lipase comes from where?
|
PANCREAS (The acnir cells of the pancreas)
|
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Bile comes from where?
|
GALLBLADDER
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CCK comes from where?
|
I cells of the SMALL INTESTINE
|
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Bicarbonate comes from where?
|
Duct cells of the PANCREAS
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The only compounds that get DIRECTLY absorbed into the blood are _____________ and ______________.
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Short chain FFA and medium chain FFA
|
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What compounds do NOT need to be transported by the micellar particles?
|
Glycerol and glucose!
|
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Bile is packaged into micelle, but what two possibilities happens to bile instead of going into intestinal cell?
BILE IS THE ONLY ONE IN MICELLE THAT DOESN'T GO INTO INTESTINAL CELL. |
-Recirculated back into the liver via the "enterohepatic circulation" (from intestines back to liver).
-Out of body! |
|
Chylomicrons are rich in _________.
HDL is rich in ________. LDL is rich in _________. |
Chylomicrons & VLDL are triglyceride rich.
HDL is protein rich. LDL is cholesterol rich. |