Blomquist: Lipid lecture Flashcards
Common saturated fatty acid
stearate
Which fatty acids have a lower boiling point: saturated or unsaturated?
unsaturated
Which fatty acids are the worst?
trans fatty acids
Two essential fatty acids
linoleic acid (n-6) linolenic acid (n-3)
These fatty acids are high in fish oils, associated with less inflammation from prostaglandins, and experts recommend we eat foods high in them
n-3 polyunsaturated fatty acids
Lipid is stored (blank), meaning that it does not require water to store it. Each gram of glycogen takes 2 grams of water to store, so lipid has (blank) times more energy per gram than CHO.
anhydrously; 6
Are glucagon receptors found on adipose tissue?
No
What is the lipase called on lipid droplets that takes TAGs to DAGs and FFAs?
ATGL = adipose TAG lipase
PKA, when stimulated by epinephrine, phosphorylates (blank) on the surface of the lipid droplet to cleave DAG into MAG and FFA.
HSL
When insulin binds to fat cells, phosphodiesterase ultimately blocks (blank) from activating PKA
cAMP
Lipid released from adipose tissue is transported and takenup into cells as (blank)
free fatty acid
Lipid taken up by digestion is transported as (blank) and hydrolyzed to (blank) in capillaries and taken up as free fatty acid
TAG; FFA
Fatty acid oxidation (breakdown) begins with (blank). A thioester bond is formed between the carboxyl group of the FA and the thiol of (blank)
activation of fatty acid; CoA-SH
What do fatty acids become when they are “activated”? What enzyme is this dependent on? How many ATP equivalents are invested?
Acyl-CoA; Acyl-CoA synthase; 2 ATP equivalents
The Acyl-CoA crosses the outer mitochondrial membrane, but to get into the matrix, the acyl group must be transferred first to (blank), carried across the membrane, and then transferred to (blank)
carnitine; CoA-SH
Carnitine Palmitoyltransferase (CPT-1) has specificity for acyl groups between (blank) carbons long
14-18
4 steps in beta oxidation of fatty acyl CoA
- Fatty acyl-CoA shortened by 2 C and then oxidized
- Hydration (gains an OH)
- Oxidation (OH become =O)
- Thiolysis (release of acetyl-CoA)
Acetyl-CoA can enter the TCA cycle by combining with OAA to form (blank)
citrate
Per Acetyl-CoA that enters, the TCA cycle generates how many FADH2? NADH? GTP?
1; 3; 1
The last beta-oxidation cycle of a fatty acid with an odd number of carbons gives (blank)
propionyl-CoA
What happens to Propionyl-S-CoA so that it may enter the TCA cycle? How many carbons does propionylCoA have? What are the enzymes that catalyze these steps?
Propionyl-S-Coa (3C) —-> Methyl-malonyl-S-CoA via a biotin containing carboxylase
Methyl-malonyl-CoA —–> succinyl-CoA (4C) via a cobalt containing mutase
Can fatty acids be glycogenic?
Yes, odd chain fatty acids, because succinyl-CoA can go to TCA cycle
The cobalt containing mutase that takes methyl-malonyl-S-CoA to succinyl-S-CoA is dependent on what vitamin?
Vit B12
What is needed to convert a UNSATURATED fatty acids to acetyl-CoA? What is the enzyme known as?
a cis-trans isomerization; isomerase
Oxidation of UNSATURATED fatty acids does not generate as much ATP as saturated fatty acids with the same number of carbons. How so?
For every double bond, 1 less FADH2 generated
Oxidation of even number poly-unsaturated fatty acids requires a (blank) step after the isomerase step.
REDUCTASE
occurs when the amount of acetyl-CoA produced is excessive compared to the amount of oxaloacetate available to react with it
Formation of ketone bodies
Conditions when ketone bodies are formed
Intake high in lipids and low in carbs
Diabetes not well controlled
Starvation