485 quizzes Flashcards
Transamination reactions require which vitamin as a cofactor?
B6
pyridoxial phosphate
Leucine catabolism takes place mainly in cells of _________ tissue.
muscle
Tryptophan serves as the precursor for formation of the neurotransmitter called
serotonin
Post-translational hydroxylation of proline in the protein that forms collagen requires _________ as a cofactor
vitamin c
During normal dietary conditions, protein nitrogen is lost from the body primarily in the form of _______.
urea
The common name for the 16 carbon saturated fatty acid is ____________.
palmitate
The common name for the 18 carbon saturated fatty acid is ____________.
stearate
How many carbons are there in linoleic acid
18
How many carbon atoms are there in docosahexaenoic acid (DHA)?
22
A fatty acid identified as 18:3 delta 9.12.15 is an n-____ fatty acid.
3
True or false.
In humans, de novo lipogenesis (fatty acid synthesis) takes place mostly in adipose cells.
False
liver
True or false.
The fatty acid composition of human adipose tissue is more similar to the composition of fatty acids synthesized in the body than to the composition of fatty acids in the diet
False
synthesized from the materials of the diet
True or false.
The use of indirect calorimetry to assess the extent of de novo lipogenesis in humans indicates that de novo lipogenesis produces a fairly small amount of fatty acids after a meal high in carbohydrates
True
body does not perform lipogenesis that much
True or false.
The de novo synthesis of saturated fatty acids in men has been estimated to be less than 1 gram per day, however synthesis of unsaturated fatty acids is much higher
False
body makes palmitate (saturated fatty acid)
True or false.
Excess carbohydrate intake (above daily energy needs) will increase glycogen storage, but have little effect on the use of fat for fuel by the body.
False
Body will utilize less of the adipose stores of fat for energy. So excess carbs will decrease use of plasma fatty acids by the body for fuel.
True or false
Glucose does not stimulate de novo lipogenesis in the liver as much as fructose does.
true
The rate of de novo lipogenesis in humans is greater on a high carbohydrate diet than it is on a high fat diet.
true
True or false
the oxidation of fatty acids requires carnitine to serve as a carrier of fatty acids across the mitochondrial membrane.
true
carnitine shuttle transports fatty acids across the inner mitochondrial membrane, into the mitochondrial space, where the enzymes that oxidize the fatty acids are.
Ketosis occurs in individuals consuming very low carbohydrate diets because there is an inadequate supply of intermediates to form oxaloacetic acid, which results in high levels of acetyl CoA in the liver.
true
as ketone body production is a runoff pathway when the CAC is full. Without oxaloacetate (primer molecule of the CAC) there is no citrate formed, etc etc
True or false.
The synthesis of fatty acids occurs in the cytoplasm using acetyl CoA units. However, acetyl CoA production occurs primarily in the mitochondria. These acetyl CoA units are transferred to the cytoplasm via citrate.
true
synthesis does occur in the cytoplasm.
due to excess CAC intermediate (oxaloacetate) can the acetyl CoA units leave as citrate.
