Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/36

Click to flip

36 Cards in this Set

  • Front
  • Back
fatty acids are a major source of fuel in the body:
-supply ... needs between meals and during periods of exertion
-during overnight fasting, fatty acids become major fuel source for ... muscle, ... muscle, and ...
-one molecule of a FA yields (more or less) ATP than a molecule of glucose
-energy
-cardiac
-skeletal
-liver
-more
fatty acid storage in adipose cells occurs as what?
triglycerides
mobilizatoin of FAs from adipose:
-triglycerides in adipose tissue under go ... (breakdown of fats) into fatty acids. These fatty acids then travel through the blood to the muscle cell and undergo ... (process of buring fatty acids) into ... (main product of beta-oxidation)
lipolysis
beta-oxidation
acetyl CoA
the particles predominantly responsible for the transport of triglycerides (and FAs) in the blood are ... and ...
chylomicrons
VLDL
what releases free fatty acids from triglycerides?
lipases
free fatty acids travel in blood complexed with ... (most abundant protein in blood)
albumin
fasting leads to high ... levels (low ... levels) which signals cAMP levels to rise within adipocytes which leads to an activation of ..., which phosphorylates and activates hormone-sensitive lipase
glucagon
insulin
protein kinase A
cellular uptake of FAs:
-fatty acids enter cells through 2 routes:
-... through the plasma membrane
-transport by a ... (...) located on the plasma membrane
-an additional fatty acid binding protein may facilitate intracellular trasport of fatty acids, particularly transport to the mitochondria (where beta-oxidation occurs)
diffusion
fatty acid binding protein
FaBP
what happens to the free FAs once they enter cells:
-fatty acids ultimately oxidized to ... and ... to produce energy (...)
-acety CoA (the major precursor that enters into the TCA cycle) produced through beta-oxidation of FAs in the liver can be (a.) converted to ... (which can also be used for fuel) or (b.) enters the ...
-glycerol and energy derived from lipolysis is used by the liver for ...
CO2
water
ATP
ketone bodies
TCA cycle
gluconeogenesis
fatty acids must be activated in the cytoplasm before being oxidized in the mitochondria. Activation is catalyzed by ..., which is expressed on the outer mitochondrial membrane
fatty acyl-CoA synthetase
acyl CoA synthetase uses ... to form fatty acyl CoA thioester bonds
ATP
once fatty acyl-CoA is generated, it can be used by # multiple pathways in the cell
3
If it enters into the mitochondria, fatty acyl CoA is used to generate energy through ... or ...(formation of ketone bodies).
beta-oxidation
ketogenesis
if it enters into the ER or peroxisomes, fatty acyl-CoA can be used for membrane synthesis of ... and ...
phospholipids
sphingolipids
Finally, fatty acyl CoA can be reconverted back into ... in the ER
triglycerides
transport of FA into mitochondria requires the ... shuttle:
-... serves as the carrier/transporter of fatty acids across the inner mitochondrial membrane.
-obtained from the ... (mostly in red meats and dairy) or synthesized from ... in the liver
-synthesis requires ... and ...
-stored in skeletal muscle
carnitine
carnitine
diet
lysine
vitamin C
S-adenosylmethionine (SAMe)
carnitine palmitoyl transferase I (CPT I):
-aka carnitine acyltransferase (CAT I)
-found on the ... mitochondrial membrane
-rate-limiting enzyme (inhibited by malonyl CoA)
-transfers the fatty acyl group to carnitine, forming fatty acylcarnitine, which is then translocated into the mitochondrial ... by carnitine acylcarnitine translocase (shuttle)
outer
matrix
Carnitine palmitoyl transferase II (CPT II):
-aka carnitine acyltransferase II (CAT-II)
-located on the ... mitochondrial membrane
-transfers the fatty acyl group back to CoASH (re-forming the fatty acyl CoA) and releases the ... for recycling
inner
carnitine
what is this?
-the enzyme expressed on the outer mitochondrial membrane that transfers the fatty acyl group from fatty acyl-CoA to carnitine. The fatty acyl group must be attached to carnitine to be able to get into the mitochondria for beta-oxidation to occur. (in other words, the inner mitochondrial membrane is impermeable to fatty acyl CoA, much like it is impermeable to acetyl CoA).
carnitine palmitoyl transferase I (CPT I)
what serves as the carrier of the fatty acyl-CoA across the inner mitochondrial membrane?
carnitine
what is the enzyme expressed on the inner mitochondrial membrane that translocates the fatty-acyl-carnitine into the mitochondrial matrix?
carnitine acylcarnitine translocase
what is the enzyme expressed on the inner mitochondrial membrane that transfers the fatty acyl group back to CoA (reforms the fatty acyl CoA) and releases carnitine for recycling?
carnitine palmitoyl transferase II (CPT II)
what are these?
-inability to transport fatty acids into the mitochondria for oxidation
-occurs in newborns (particularly pre-term infants), patients undergoing hemodialysis, patients with organic acidemia
-symptoms: muscle weakness, muscle cramping, cardiomyopathy, hepatomegaly, encephalopathy, sudden death
deficiencies in carnitine
CPT I deficiency:
-autosomal ... defect in CPT I gene
-primarily affects ... in the liver
-symptoms usually present after a period of fasting or after a gastrointestinal illness: ...(low amounts of ketone bodies in blood stream) and hypoglycemia, lethargy, seizures, coma
recessive
fatty acid oxidation
hypoketosis
CPT II deficiency:
-autosomal ... defect in CPT II gene
-3 subtypes: ... CPT-II deficiency (most common), ... CPT-II deficiency (similar to CPT-I), and ... CPT-II deficiency (rare, fatal)
-symptoms of myopathic CPT-II deficiency: onset usually in adolescence or adulthood, recurrent muscle pain, fatigue, and myoglobinuria (particularly following exercise), often misdiagnosed (fibromyalgia, chronic fatigue)
recessive
myopathic
hepatic
multiorgan
the beta-oxidation spiral:
-fatty acyl group sequentially cleaved into 2-carbon ... units
-initial step is oxidation of the ...
acetyl CoA
beta-carbon
each oxidation at the beta-carbon of the fatty acid chain involves what 4 intermediate steps?
oxidation
hydration
oxidation
cleavage
what is the enzyme that catalyzes the first step (initial oxidation of the beta-carbon) in the spiral and is also involved in several metabolic disorders?
acyl CoA dehydrogenase
the chain length specificity of 6-12 of an acyl CoA dehydrogenase enzyme is the (very long, long, medium or short) chain enzyme
medium
what is this?
-most frequently diagnosed of the fatty acid oxidation disorders
-autosomal recessive trait: incidence is 1 in 20,000; 1 in 80 healthy people are carriers
-most common in caucasians of the northern european descent
-accounts for about 1 in 100 SIDS deaths (sudden infant death syndrome)
MCAD deficiency
MCAD deficiency:
-impairment of oxidation of ... chain fatty acids (6-12 carbons)
-usually presents clinically between ... month and .. year of life following a period of fasting (even overnight fasting) or illness
-symptoms: vomiting, lethargy, muscle weakness, hypoglycemia, hepatomegaly, developmental and behavioral disorders, coma, cardiopulmonary arrest, death
-prevention: frequent feedings, high-carb/low-fat diet (don't let the child go through the night without eating if they have this deficiency)
medium
second
second
MCAD deficiency:
-20-25% of patients will die with their first episode of illness

-disease management:
-eat ..., avoid ... (babies must feed every 4-6 hours)
-diet high in ..., low in medium and long chain fatty acids
-oral ... supplementation

-North Carolina and Massachusetts (maybe California) offer MCAD deficiency testing as part of their newborn screening programs
regularly
fasting
carbs
carnitine
during the oxidation steps of beta-oxidation, ... and ... are being generated. These electron carriers can then enter the electron transport chain and form ... through oxidative phosphorylation. This is how energy is being produced when fatty acids are oxidized.

Also remember that the acetyl CoA produced can enter the TCA cycle and generate even more ...
FAD(2H) and NADH
ATP

ATP
most common fatty acids used for energy through beta-oxidation:
-saturated long chain fatty acids --> ...(C16) and ...(C18)
-monounsaturated fatty acid --> ...(C18:1)
-polyunsaturated fatty acid --> ...(C18:2)

these are the most commonly oxidized fatty acids because they are the most common dietary fatty acids and also most commonly synthesized in humans
palmitate and stearate
oleate
linoleate
oxidation of unsaturated fatty acids:
-#% of fatty acids in the human diet are unsaturated
-... (C18:1) and ...(C18:2) are the most common
-cis double bonds must be isomerized to trans (isomerase), and the double bond must be reduced (reductase) prior to beta-oxidation
50%
oleate
linoleate
3 main routes involved in beta-oxidation regulation:
-... (glucagon, epinephrine, beta-corticotropin)
-... (from fatty acid synthesis) (will feed back and inhibit)
-rate of ... utilization and electron transport chain
hormones
malonyl CoA
ATP