NUTR 313 Final Exam Questions and
Answers (Top Grade Assured) 2026
Update
What are the food sources of iodine? - Correct Answers
✅Seafoods and iodized salt
Food content is variable based on soil
How is iodine absorbed? - Correct Answers ✅Organic
bound iodine is freed and converted to iodide within the
gastrointestinal tract
What is the single main function of iodine? - Correct
Answers ✅The synthesis of thyroid hormones
How is thyroid hormone synthesized from iodine? - Correct
Answers ✅Thyroid peroxidase, a membrane-bound
glycoprotein, catalyzes the oxidation of the iodide to the
active form I2. The binding of this active form to the tyrosine
in the thyroglobulin to form MIT or DIT (monoiodotyrosines or
diiodotyrosines).
MIT or DIT then condense to form thyroid hormones.
DIT+DIT = T4
MIT+DIT = T3
How is thyroid hormone status regulated? - Correct
Answers ✅Stimulation of the thyroid gland causes the
release of the hormones into circulation.
,NUTR 313 Final Exam Questions and
Answers (Top Grade Assured) 2026
Update
The releasing of thyroid hormone is controlled by the thyroid
stimulating hormone (TSH) from pituitary, which in turn is
controlled by thyroid releasing hormone (TRH) from the
hypothalamus.
This hypothalamic-pituitary-thyroid axis is responsible for
producing the appropriate amounts of thyroid hormones, but
thyroid status can also be regulated by altering the rate of T4
to T3 conversion by deiodinases.
What is the function for selenium containing 5'-, and 5-
deiodinase? - Correct Answers ✅5'-deiodinase catalyzes
the deiodination (removal) of iodine from the 5' position of
T4. This forms active T3.
5-deiodinase catalyzes the deiodination (removal) of iodine
from the 5 position of T4. This forms inactive T3.
What are some of the selected physiological function for
thyroid hormone? - Correct Answers ✅Enhances lipolysis in
adipose tissue
Enhances contraction of muscle
Promotes anabolism of bone
Increases the heart rate
Stimulates nutrient digestion and absorption
Stimulates metabolic rate and cellular oxygen consumption in
metabolically active tissues
, NUTR 313 Final Exam Questions and
Answers (Top Grade Assured) 2026
Update
How does thyroid hormone act on regulating gene expression
thereby regulating physiological functions? - Correct
Answers ✅On a target gene promoter, TR forms a
heterodimer with RXR (retinoid X receptor). In the absence of
T3, this dimer is associated with a co-repressor, which has
histone deacetylase activity.
This complex also interacts with TFIIB basal transcriptional
machinery, and inhibits transcription.
In the presence of T3, a co-activator replaces co-repressor.
This results in histone acetylation and initiation of
transcription.
What are the deficiencies associated with iodine? - Correct
Answers ✅Goiter
Iodine deficiency disorders (IDDs)
Cretinism
Goiter - Correct Answers ✅Enlargement of the thyroid
gland
Caused by over stimulation of TSH
Iodine deficiency disorders (IDDs) - Correct Answers ✅An
insufficient supply of iodine during pregnancy is associated
with an increased occurrence of spontaneous abortions,
Answers (Top Grade Assured) 2026
Update
What are the food sources of iodine? - Correct Answers
✅Seafoods and iodized salt
Food content is variable based on soil
How is iodine absorbed? - Correct Answers ✅Organic
bound iodine is freed and converted to iodide within the
gastrointestinal tract
What is the single main function of iodine? - Correct
Answers ✅The synthesis of thyroid hormones
How is thyroid hormone synthesized from iodine? - Correct
Answers ✅Thyroid peroxidase, a membrane-bound
glycoprotein, catalyzes the oxidation of the iodide to the
active form I2. The binding of this active form to the tyrosine
in the thyroglobulin to form MIT or DIT (monoiodotyrosines or
diiodotyrosines).
MIT or DIT then condense to form thyroid hormones.
DIT+DIT = T4
MIT+DIT = T3
How is thyroid hormone status regulated? - Correct
Answers ✅Stimulation of the thyroid gland causes the
release of the hormones into circulation.
,NUTR 313 Final Exam Questions and
Answers (Top Grade Assured) 2026
Update
The releasing of thyroid hormone is controlled by the thyroid
stimulating hormone (TSH) from pituitary, which in turn is
controlled by thyroid releasing hormone (TRH) from the
hypothalamus.
This hypothalamic-pituitary-thyroid axis is responsible for
producing the appropriate amounts of thyroid hormones, but
thyroid status can also be regulated by altering the rate of T4
to T3 conversion by deiodinases.
What is the function for selenium containing 5'-, and 5-
deiodinase? - Correct Answers ✅5'-deiodinase catalyzes
the deiodination (removal) of iodine from the 5' position of
T4. This forms active T3.
5-deiodinase catalyzes the deiodination (removal) of iodine
from the 5 position of T4. This forms inactive T3.
What are some of the selected physiological function for
thyroid hormone? - Correct Answers ✅Enhances lipolysis in
adipose tissue
Enhances contraction of muscle
Promotes anabolism of bone
Increases the heart rate
Stimulates nutrient digestion and absorption
Stimulates metabolic rate and cellular oxygen consumption in
metabolically active tissues
, NUTR 313 Final Exam Questions and
Answers (Top Grade Assured) 2026
Update
How does thyroid hormone act on regulating gene expression
thereby regulating physiological functions? - Correct
Answers ✅On a target gene promoter, TR forms a
heterodimer with RXR (retinoid X receptor). In the absence of
T3, this dimer is associated with a co-repressor, which has
histone deacetylase activity.
This complex also interacts with TFIIB basal transcriptional
machinery, and inhibits transcription.
In the presence of T3, a co-activator replaces co-repressor.
This results in histone acetylation and initiation of
transcription.
What are the deficiencies associated with iodine? - Correct
Answers ✅Goiter
Iodine deficiency disorders (IDDs)
Cretinism
Goiter - Correct Answers ✅Enlargement of the thyroid
gland
Caused by over stimulation of TSH
Iodine deficiency disorders (IDDs) - Correct Answers ✅An
insufficient supply of iodine during pregnancy is associated
with an increased occurrence of spontaneous abortions,
