-
Are lipids hydrophobic or hydrophilic ?
Hydrophobic
Hydorphobic
-
Where do lipids began to digest ?
What enzyme digests lipids ?
Stomach
Lipase
-
What molecule is this ?
Fatty Acid
Triacylglycerol
Phospholipid
Steroid
Glycolipid
Fatty Acid
-
What molecule is this ?
Fatty Acid
Triacylglycerol
Phospholipid
Steroid
Glycolipid
Triacylglycerol
-
What molecule is this ?
Fatty Acid
Triacylglycerol
Phospholipid
Steroid
Glycolipid
Phospholipid
-
What molecule is ?
Fatty Acid
Triacylglycerol
Phospholipid
Steroid
Glycolipid
Steroid
-
What molecule is this ?
Fatty Acid
Triacylglycerol
Phospholipid
Steroid
Glycolipid
Glycolipid
-
What emulsifies fat in the duodenum of
the small intestine ?
Why is fat emulsified ?
Bile Salts
In order to make portions smaller for absorption
-
What degrades the dietary lipids ?
What enzyme degrades TAGs ?
Pancreatic enzymes
Pancreatic Lipase
-
Why do the dietary lipids get degraded
by pancreatic enzymes ?
Where does the pancreatic lipase
preferentially cleave the Fatty Acids from Triacylglycerol ?
They are too large for digestion and absorption by enterocytes
C1 and C3
-
What hydrolyzes ( Cholsteryl ester )
into ( Cholesterol and Fatty acids ) ?
Cholesteryl esterase
-
In terms degradation of dietary lipids by
pancreatic enzymes what enzyme removes a single Fatty Acid from C2 of a TAG leaving a lysophospholipid ?
In terms degradation of dietary lipids by
pancreatic enzymes what enzyme removes the FA at C1 leaving a glycerophosphoryl base ?
Phospholipase A2
Lysophospholipase
-
What are the two hormonal control for
lipid digestion in the small intestine ?
Cholecystokinin and Secretin
-
What is the function of Secretin ?
Promotes Bicarbonate secreton into the small intestine
-
What is the function of Cholecystokinin ?
- -Stops Gastric Motility
- -Promotes Secretion of Bile and Pancreatic Enzymes
-
What is the composition of mixed
micelles ?
What is the primary site for lipid
absorption ?
Lipids , bile salts , and fat soluble vitamins
Brush border membrane
-
Where does resynthesis of TAG
and cholesterol esters take place ?
Endoplasmic Reticulum
-
What is it called when a person has lipid
in their feces ?
Steatorrhea
-
Newly resynthesized TAGs and cholesteryl esters are very hydrophobic, and
aggregate in an aqueous environment
so they are packaged in ?
Chylomicrons
-
Since Chylomicorns are to big for blood vessels where do they go ?
Lymphatic vessels
-
Explain the route in which Triacylglycerols enter the enterocytes to the lymphatic vessels ?
Pacnreatic Lipase> Fatty acids + Monoglycerol > 2 Fatty acyl-CoA +Monoacyl-glycerol > Triacylglycerol > Chylomicrons
-
What are the different forms that FA’s
exist in the body ?
Free Fatty Acids can be oxidized by
many tissues to produce energy ,particularly by what organs ?
- -Free fatty acids
- Fatty acyl esters in TAGs
-Liver and Muscle
-
What makes a fatty acid amphipathic ?
A fatty acid consists of a hydrophobic hydrocarbon chain with a terminal hydrophilic carboxyl group.
-
What is the percentage of Fatty acid
esters found in plasma ?
90%
-
What are fatty acids ?
How long do they tend to be ?
Monocarboxylic acids that typically contain hydrocarbon chains of variable lengths
Between 12 and 20 or more carbons
-
How are fatty acids numbered ?
Where do you usually find fatty acids ?
From the carboxylate end
triacylglycerols and several types of membrane bound lipid molecules
-
What are saturated vs unsaturated fatty acid chains ?
Fatty acid chains that contain only carbon-carbon single bonds are termed saturated
Fatty acid chains that contain one or more double bonds are termed unsaturated
-
What form tends to persist when discussing fatty acids , Cis or Trans ?
Cis
-
Why are cis double bonds better ?
cis double bonds cause an inflexible “kink” in a FA chain, therefore unsaturated Fats do not pack as tightly together and have a lower melting point (liquids at room temp.)
-
How does hydrocarbon chain length
change the melting point ?
How many spaces do Double bonds have to
be spaced ?
Longer the chain the higher the melting point
3 carbon intervals
-
Make this acid ?
Arachidonic acid, 20:4 (5,8,11,14)
-
What is the difference between linoleic acid and a-linolenic acid ?
Linoleic acid - 18:2 (9, 12)
a-linolenic acid - 18:3 (9, 12, 15)
-
What are the two essential FA’s ?
What are FA’s that can be synthesized
by the body called ?
-Linoleic acid and a-linolenic acid
-Nonessential FA’s
-
Carbohydrates and proteins obtained
from the diet in excess of the body’s needs can be converted to fatty acids which are
stored as ?
Triacylglycerols
-
In adults where does fatty acid
synthesis occur ?
- Liver (mainly)
- Lactating mammary glands
- Adipose tissue (to a lesser extent)
-
Where does fatty acid occur within a
cell ?
How are carbons incorporated into a
chain ? Does this require energy ?
Cytosol
They are added using acetyl CoA , yes ATP and NADPH
-
How many units are added at one time to
the growing carbon chain ?
Two-carbon units
-
In order for Acetyl CoA to make it out of the mitochondria for fatty acid synthesis what does it have to be changed into ?
Citrate
-
Fatty acid synthesis is in cytosol ,
Breakdown /beta oxidation is in the ?
Where does the actyl-CoA come
from to build the fatty acid in the cytosol ?
Mitochondrial Matrix
Mitochindria
-
Explain Fatty acid Synthesis ?
1- synthesis of acetyl ACP and malonyl ACP from acetyl CoA
- 2-Acetoacetyl-ACP formation of a 4 carbon unit attached
- to ACP,
-Palmitate
-
FAS
is a multifunctional enzyme, the enzyme activities listed are separate catalytic
domains present in each FAS monomer
no answer , case and point
-
After palmitic acid how many more carbons can be added ?
Where does this take place ?
2 carbons
Endoplasmic Reticulum
-
What is the function of desaturases ?
Where does desaturase usually place the first double bond ? Can it go past Carbon 9 ?
They add cis double bonds
Usually inserted between carbons 9 and 10 , no it can not.
-
In terms of a Triacylglycerol what
does mono , di , and tri stand for ?
What is a species of acylglycerol called when it is a solid at room temperature , how about a liquid and room temprature ?
one, two or three molecules of fatty acid esterified to a molecule of glycerol
-
The 3 fatty acids esterified to a glycerol
molecule are usually not of the same type What are they usually ?
- Carbon #1 is typically saturated
- Carbon #2 is typically unsaturated
- Carbon #3 can be either
-
TAGs are only slightly soluble in water
and cannot form stable micelles by themselves so they coalesce with ?
They coalesce within adipocytes to form oily droplets that are nearly anhydrous
-
What is the initial acceptor of FAs during TAG synthesis ?
glycerol phospahte
-
What does a FA have to be attached to
in order for in to participate in TAG synthesis ?
What family of enzymes catalyze this
reaction ?
CoA
fatty acyl CoA synthetases
-
How is TAG stored in adipose ?
How much TAG is stored in the Liver ?
It is stored in anhydrous form
Very little
-
Where is TAG stored as the major source
of energy for the body ?
The oxidation of fatty acids provide
how much Kcal/gram ?
Adipose Tissue
9 Kcal/gram
-
The mobilization of stored fat requires the hydrolytic release of fatty acids and glycerol from their TAG form. This process is
initiated by what enzyme ?
hormone-sensitive lipase.
-
Where does the enzyme hormone-sensitive
lipase cleave the fatty acid from on a Triacylglycerol ?
removes a fatty acid from carbon 1 and or carbon 3 of the TAG
-
The major pathway for catabolism of
fatty acids is a pathway called ?
β-oxidation
-
Transport of long chain fatty acids (LCFA) into the mitochondria via what shuttle ?
How do short chains get across ?
Carnitine shuttle
Diffuse
-
In B-oxidation the Two-carbon fragments that are successively removed from
the carboxyl end of a fatty acid is ?
fatty acyl CoA, producing acetyl CoA
-
Where do Very long chain fatty
acids (22 carbons or longer) undergo a preliminary β-oxidation ?
Peroxisomes
-
Liver mitochondria have the capacity to convert acetyl CoA derived from fatty acid oxidation into ?
ketone bodies
-
A person who has diabetes has a problem with carbohydrate catabolism what will you see ?
Ketone bodies being produced because of lipid breakdown.
-
What energy sources does the brain use ?
ketones and glucose
-
What does HMG CoA synthase do ?
Makes Acetyl-CoA and Acetoacetate
-
What makes the Fruity odor from beta oxidation?
During a fast, the liver is flooded with fatty acids mobilized from where ?
When the rate of formation of ketone bodies is greater than the rate of their use, their levels begin to rise in the blood , what is it called ? eventually,it increases in the urine
what is it called ?
Acetone
Adipose
ketonemia - ketouria
-
What are the predominant lipids of cell
membranes ?
Phospholipids
-
Name these Phosplipid compunds ?
-
What is cardiolipin’s composition ?
Two molecules of phosphatidic acid (PA) esterified through their phosphate groups to an additional molecule of glycerol is called cardiolipin
- Cardiolipin is antigenic and is
- recognized by antibodies raised against Treponema pallidum (bacterium that
- causes syphilis)
-
Where does phospholiase A2 cleave ?
Where does phospholiase A1 cleave ?
Where does phospholiase D cleave ?
Where does phospholiase C cleave ?
-
What does sphingomyelinase cut ?
-
How do you tell the difference between glycosphingolipid and Sphingomyelin ?
Sphingomyelin has the choline group
-
How do you tell a glycolipid ?
- Look for glycosidic bond
-
What is the charge of this group ?
Negative
-
Degradation of sphingolipids , know these two enzymes.
Neuroaminidase
B-Galactosidase
-
Prostaglandins and thromboxanes are derived from what ?
arachidonic acid or eicosapentaenoic acid (EPA)
-
The first step in the synthesis of prostaglandins is the oxidative cyclization of free arachidonic
acid to yield PGH2 by what enzymes ?
- COX-1 (constitutive) and
- COX-2 (nonconstitutive)
-
Leukotrienes can be synthesized
from AA by what enzyme ?
lipoxygenases
-
What is cholesterol ?
It is a steroid alcohol
-
What is the function of cholesterol ?
- 1)structural component of membranes,
- modulating fluidity
- 2)precursor of bile acids, steroid
- hormones and vitamin D
-
What is the difference between Cholesteryl esters and Sterols ?
1.Cholesteryl esters are an esterified form (with a fatty acid attached at carbon 3).
- 2. Sterols are steroids with a
- 8 to 10 carbon, branched hydrocarbon chain attached to carbon 17 of the D ring
- and OH group at carbon 3 on ring A
-
What is the main enzyme for cholesterol synthesis ?
What can act as an inhibitor for this process
HMG-CoA reductase is the key enzyme for cholesterol synthesis.
Cholesterol itself
-
What is the general process for cholesterol synthesis ?
Mevalonate > Squalene > Cholesterol
-
How does the body remove cholesterol ?
It has to be turned into bile salts first. It can not be metabolized into CO2 and H2O.
-
What is HDL ?
- –Transports cholesterol from peripheral tissues to the liver
- -“Good cholesterol "
-
What is LDL ?
- –Transport cholesterol to tissues
- –“Bad cholesterol”
-
What is VLDL ?
- –Produced in the liver
- –Transport lipids from liver to peripheral tissues
- –When depleted become LDLs.
-
What are Chylomicrons ?
- –Assembled in the intestine
- –Transport lipids from intestine to peripheral tissues
-
What are exogenous lipids ?
The lipids from the diet
-
What molecule is this ?
Cortisol
Progesterone
Testosterone
Estradiol
Aldosterone
Cortisol
-
What molecule is this ?
Cortisol
Progesterone
Testosterone
Estradiol
Aldosterone
Testosterone
-
What molecule is this ?
Cortisol
Progesterone
Testosterone
Estradiol
Aldosterone
Estradiol
-
What molecule is this ?
Cortisol
Progesterone
Testosterone
Estradiol
Aldosterone
Aldosterone
-
What molecule is this ?
Cortisol
Progesterone
Testosterone
Estradiol
Aldosterone
Progesterone
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