Term
What enzymes are used for digestion in the stomach?
What are they used for exactly? |
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Definition
Lingual lipase & Gastric lipase
Used for short-medium cahins (like milk)
lipid digestion
Shortage of lipase leads to Cystic Fibrosis: mutation in Cl- channel, cannot secrete Cl-. Without doing this, you can secrete pancreatic enzyme and you don’t have lipase enzyme to help break down fat and lipids for energy |
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Term
What are bile salts?
Where are they made? Stored? |
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Definition
derivatives of cholesterol that prevent lipids from coalescing.
These are made in the liver and stored in gall bladder |
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Term
| Products of lipid digestion |
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Definition
Free fatty acids
Cholesterol
Some remaining PL |
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Term
| 2 substances to control lipid digestion |
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Definition
1. Cholecystokinin: releases bile/pancreatic enzymes on gallbladder in presence of lipids. decreases gatric motility
2. Secretin: released in low pH of chyme. Will cause pancreas and liver to release bicarbonate |
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Term
The products of lipid digestion are mixed with bile salt and vitamins to form what?
Why is this necessary? |
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Definition
| Forms micelles, which are amphipathic. Necessary so the FAs and cholesterol may be absorbed through cell membranes of enterocytes of small intestine |
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Term
| Fates of short, medium, long chained FAs that enter enterocytes |
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Definition
Short and med chained FAs will be carried by albumin into portal circulation to the liver
Long chained FAs will enter enterocytes and synthesize into TAGs, choleterol esters, phospholipids (active forms that can be used by body) |
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Term
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Definition
| "packages", transporters used to surround hydrophobic TAGs so they can leave enteropatic cells and be stored in adipose tissue |
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Term
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Definition
Once delivered as TAG by chylomicron into skeletal muscle and adipose tissue,
Can directly enter adjacent cells (adipocytes), transport into blood via albumin. |
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Term
| Where are esterified fatty acids (aka TAGs) stored? |
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Definition
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Term
| The two fatty acids, _____ and ____, are essential for human growth and development |
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Definition
Linoleic acid
alpha- linoleic acid |
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Term
| major supplier of NADPH for fatty acid synthesis |
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Definition
hexose monophosphate pathway
Involves the cytosolic conversion of malate to pyruvate, produces NADPH and CO2 |
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Term
FA positions on TG distinguish what type of fat?
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Definition
Position 1 is saturated fat
Position 2 is unsaturated fat
Position 3 can be either one |
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Term
HSL function and means of activation
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Definition
HSL is an enzyme used to oxidize TG into fatty acids
Can be activated by epinephrine or glucagon |
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Term
True of False:
The brain and RBCs can use free fatty acids |
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Definition
False
Neither location can use free FAs because neither have mitochondria, which is necessary for the utilization of FAs |
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Term
What is beta FA oxidation?
Where does it take place?
What is the end result? |
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Definition
Used to catabolise free FAs
Happens in mitochondria
Yields NADH, acetyl CoA, FADH |
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Term
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Definition
serves as a transport system for long chain FAs into mitochondria. Inhibited by malonyl
Carnate comes from red meat, and 97% of it is stored in skeletal muscle.
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Term
| Name the reactions and products of beta FA oxidation |
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Definition
FA oxidation yields FADH2. Hydration. 2nd oxidation yields NADH. Thiolytic cleavage yields acetyl CoA
Final cleavage will produce 2 acetyl groups |
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Term
ATP gained from activation of FAs
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Definition
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Term
| Redox coenzymes in the synthesis and degradation of long chain FAs |
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Definition
Synthesis:NADpH
Degradation:NAD+, FAD |
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Term
When does long chain FA synthesis occur?
When does degradation occur? |
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Definition
Synthesis occurs after eating a carb-rich meal
Degradation occurs during starvation |
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Term
| Pathway products of Long chain FA synthesis and degradation |
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Definition
product of synthetic path is plamotate.
product of degradation is acetyl CoA |
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Term
| Oxidation of odd numbered FAs |
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Definition
3 more steps are required. Coenzyme biotin will form D-methylmanol
D-isomer ® L-form by the enzyme, methylmalonylCoAracemase.
carbons of L-methylmalonylCoA are rearranged, forming succinylCoA, enter TCA , (coenzyme vitamin B12) |
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Term
| monounsaturated fats require what enzyme for oxidation? |
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Definition
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Term
| Liver mitochondria can convert ____ derived from FA oxidation into ____ |
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Definition
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Term
| Brain in prolonged fasting |
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Definition
| Will use ketone bodies for energy in order to spare glucose |
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Term
| rate limiting step in ketone body synthesis |
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Definition
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Term
| In ketone body synthesis, _____ is oxidized into ______, to NADH |
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Definition
3-hydroxybutarate
acetoacetate |
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Term
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Definition
Diabetes Mellitus
High FA degradation= high levels of AcCoA (which has to go to KB pathway)
Leads to ketoacidosis and excessive amounts of KB excreted in urine (sweet urine) |
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