Unit II Fat Burning Flashcards
What are the two essential fatty acids that must be acquired through the diet?
Linoleic acid and alpha-linolenic acid
What are essential fatty acids used to make?
Omega-3 and 6 fatty acids
Nomenclature of linoleic acid
18:2w6
Nomenclature of Linolenic acid
18:3w3
Nomenclature of Arachidonic acid
20:4w6
Nomenclature of Eicosapentaenoic Acid
20:5w3
Nomenclature of Docosahexaenoic Acid
22:6w3
Nomenclature of Palmitic Acid
16:0
Nomenclature of Steric Acid
18:0
Nomenclature of Oleic Acid
18:1w9
Triglycerides are also
triacylglycerols or TAG
Satured FA’s have how many double bonds?
0
How is most fat stored in the body?
as TAG
Monoacylglyceride has how many LCFA’s? (long chain fatty acids)
just one
Diacylglycerol has how many LCFA’s?
two
Triacylglycerol has how many LCFA’s?
three
Short chain or unsaturated fat is what at room temp?
liquid
Long chain or saturated fat is what at room temp?
solid
What accounts for 95% of dietary fat?
TAG
What type of enzyme is used to break down lipids?
esterases
Where does the breakdown of lipids occur?
in the GI tract
What specific bond does an esterase cleave?
the ester bond
Lipases break down what?
TAG
Phospholipases break down what?
phospholipids
Cholesterol esterases break down what?
cholesterol esters
Digestion in the mouth starts with what enzyme?
linguinal lipase
Digestion in the stomach starts with what?
gastric lipases
Where are most TAG’s broken down?
in the small intestine
Once TAG’s are broken down somewhat, what takes over next?
pancreatic lipases to create DAG, MAG, and FFA
Where are DAG, MAG and FFA transported to?
enterocytes
Medium chain FFA can pass directly into where?
the portal blood
Once in the portal blood, what can DAG, MAG, and FFA bond to?
albumin to be taken to the liver
LCFA’s are added to DAG and MAG to form TAG, what is this then incorporated with?
chylomicrons
How can chylomicrons leave enterocytes?
through exocytosis and enters the lymph
What else does a chylomicron transport with TAG?
a cholesterol
What form does cholesterol take on the surface of a chylomicron?
unesterfied free cholesterol
Apolipoproteins are important for?
specific receptors on the cell surface
Lipoprotein complexes do what?
transport lipids from tissue to tissue
What else is a lipoprotein complex known as?
a chylomicron
Where are chylomicrons formed again?
in the enterocyte
How long can chylomicrons last after a meal?
up to 14 hours
What is the abundant lipid in the diet?
TAG
What tissue receives 80% of dietary TAG?
muscle
What extracellular enzyme hydrolyzes TAG’s?
lipoprotein lipase
What does TAG get broken down to by LPL?
FFA and DAG
What is LPL produced by?
fat and muscle cells
Where does the hydrolyzation of TAG occur?
in capillary beds
In the muscle what happens to the FA?
it is oxidized for energy
In adipose tissue what happens to FA?
FA gets re-esterfied and stores it as TAG’s
Exercise can result in an increase in what?
skeletal muscle LPL
Is skeletal muscle LPL higher in trained individuals compared to none trained?
yes
What is synthisized in the SER (smooth endoplasmic reticulum)?
lipid
Once lipid is made in the SER where is it sent to next?
the golgi apparatus
What is the lipid excreted with from the golgi apparatus?
an apolipoprotein
What is removed quicker, chylomicrons or VLDL’s?
chylomicrons
Where are a vast majority of TAG’s stored?
in subcutaneous and visceral apidose tissue
What is the storage form of a fat cell?
lipid droplets
What are steroid synthesizing cells?
adrenal cortex, ovary, testes
If there is an over abundance of lipids where are triglycerides stored?
intramuscular triglycerides (IMTG)
What would be the source of fatty acids during exercise?
IMTG
Which type of muscle fiber stores 2-3 times more IMTG?
Type I aerobic muscle fibers
Could a single bout of exercise lower the amount of IMTG?
yes
This population has lower IMTG and moderate insulin sensitivity
normal populations
This population has elevated oxidative capacity, higher concentrations of IMTG and greater insulin sensitivity
athletes
This poulation has higher IMTG and low insulin sensitivity
obese individuals
What forms lipoproteins or VLDL’s?
the liver
Would would be a couple of examples that serve as precursors for the synthesis of new lipids from non-lipids?
glucose and amino acids
Where do the remnants of chylomicrons get shipped to?
the liver
Chylomicron remnants serves what purpose in the liver?
they repackage lipids into HDL and VLDL forms,and also provide energy
Post meal, describe the fate of the macronutrients
glucose, amino acids, and medium chain FA’s enter portal blood
Once the macronutrients post meal are in portal blood, where does it go?
it is sent directly to the liver
Once the macronutrients post meal are in the portal blood of the liver, what happens to gluose?
glycogensis takes place and fatty acid synthesis
Chylomicrons deliver what two things to adipose tissue?
TAG and cholesterol
What is the major storage site for TAG again?
adipose tissue
What is TAG adiposity regulated by?
nutrition, metabolic state, and hormonal factors
The synthesis of adipocyte FA is stiumalted by?
insulin
What effect does insulin have on the availability and uptake of FA in adipocytes?
its increases it
What does insulin strongly inhibit that hydrolyzes stored TAG?
Hormone sensitive lipase
Describe glucose levels during fasting
They are diminshed
During fasting insulin is _____ and glucagon is _________
decreased
increased
Free fatty acids are transported in the blood with what?
Albumin
What does the complete hydrolysis of TAG yield?
glycerol and 3 FA’s
What gets lipid into a target cell again?
Lipoprotein lipase
What lipase converts TAG to DAG?
adipose triglyceride lipase (ATGL)
What lipase converts DAG to MAG?
hormone sensitive lipase (HSL)
What lipase converts MAG to FFA?
monoacyglycerol lipase (MGL)
Intracellular lipase is stimulated by
Hormones: epinephrine, glucagon, and adrenocorticotropic hormone
Once a hormone attaches to the receptor on a TAG, what phosphorylates TAG to the active form?
cAMP and adenyl cyclase, 2nd messengers
What does cAMP stimulate?
protein kinase A
What would PKA stimulate when associated with a TAG?
it will stimulate lipolysis
Besides lipolysis, what does PKA stimulate in catabolism of TAG?
horone sensitive lipase (HSL)
On the surface of TAG, what receptor do stimulating hormones attach to?
Beta 1
What does insulin remove from TAG to deactive HSL?
a phosphate group
If HSL is inhibited, what other lipase is also inhibited?
ATGL
Describe the fate of glycerol
Transported in the blood to liver
phosphorylated to glycerol-3-phosphate
G-3-P is then converted to DHAP to be used in glycolysis or gluconeogenesis
What enzyme converts G-3-P to DHAP?
G-3-P dehydrogenase
