MCAT 2025-2026: THE ENDOCRINE SYSTEM | ACE
EVERY TEST | 100% VERIFIED ANSWERS INSIDE.
Peptide Hormones - Answer: Composed of amino acids and are derived from larger
precursor proteins that are cleaved during posttranslational modification.
What is the chemical precursor for Peptide Hormones? - Answer: Amino Acid
What is the chemical precursor for Steroid Hormones? - Answer: Cholestrol
What is the location of the receptor for Peptide Horomones? - Answer: Extraceullular
What is the location of the receptor for Steroid Horomones? - Answer: Intracellular or
intranuclear
Peptide hormones method of travel in the bloodstream? - Answer: Dissolves/travels
freely
Steroid hormones method of travel in the bloodstream? - Answer: Binds to carrier
protein
Speed of onset and duration of action of Peptide Hormones? - Answer: Quick & short-
lived
Speed of onset and duration of action of Steroid Hormones? - Answer: Slow & long-
lived
How are amino acid-derivative hormones synthesized? - Answer: By modifying amino
acids
1
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, Direct Hormone - Answer: Secreted into bloodstream & travel to a target tissue where
they have direct effects
Tropic Hormone - Answer: Cause secretion of another hormone that then travels to
target tissue to cause an effect
Which two hormones are primarily involved in calcium homeostasis? - Answer:
Calcitonin and PTH (Parathyroid Hormone)
Where does the calcitonin hormone come from and what effect does it have on blood
calcium concentrations? - Answer: Calcitonin comes from the parafollicular (C-) cells of
the thyroid decreases blood calcium concentration
Where does the PTH (Parathyroid) hormone come from and what effect does it have on
blood calcium concentrations? - Answer: They come from the parathyroid glands and
they increase blood calcium concentration
Which endocrine tissue synthesizes catecholamines? - Answer: Adrenal Medulla
What are the two main catecholamines produced? - Answer: Epinephrine and
Norepinephrine
Which two pancreatic hormones are the major drivers of glucose homeostasis? -
Answer: Glucagon & Insulin
Where does glucagon come from and what effect does it have on blood glucose
concentrations? - Answer: Glucagon comes from alpha cells, and it increases blood
glucose concentrations
2
APPHIA - Crafted with Care and Precision for Academic Excellence.
EVERY TEST | 100% VERIFIED ANSWERS INSIDE.
Peptide Hormones - Answer: Composed of amino acids and are derived from larger
precursor proteins that are cleaved during posttranslational modification.
What is the chemical precursor for Peptide Hormones? - Answer: Amino Acid
What is the chemical precursor for Steroid Hormones? - Answer: Cholestrol
What is the location of the receptor for Peptide Horomones? - Answer: Extraceullular
What is the location of the receptor for Steroid Horomones? - Answer: Intracellular or
intranuclear
Peptide hormones method of travel in the bloodstream? - Answer: Dissolves/travels
freely
Steroid hormones method of travel in the bloodstream? - Answer: Binds to carrier
protein
Speed of onset and duration of action of Peptide Hormones? - Answer: Quick & short-
lived
Speed of onset and duration of action of Steroid Hormones? - Answer: Slow & long-
lived
How are amino acid-derivative hormones synthesized? - Answer: By modifying amino
acids
1
APPHIA - Crafted with Care and Precision for Academic Excellence.
, Direct Hormone - Answer: Secreted into bloodstream & travel to a target tissue where
they have direct effects
Tropic Hormone - Answer: Cause secretion of another hormone that then travels to
target tissue to cause an effect
Which two hormones are primarily involved in calcium homeostasis? - Answer:
Calcitonin and PTH (Parathyroid Hormone)
Where does the calcitonin hormone come from and what effect does it have on blood
calcium concentrations? - Answer: Calcitonin comes from the parafollicular (C-) cells of
the thyroid decreases blood calcium concentration
Where does the PTH (Parathyroid) hormone come from and what effect does it have on
blood calcium concentrations? - Answer: They come from the parathyroid glands and
they increase blood calcium concentration
Which endocrine tissue synthesizes catecholamines? - Answer: Adrenal Medulla
What are the two main catecholamines produced? - Answer: Epinephrine and
Norepinephrine
Which two pancreatic hormones are the major drivers of glucose homeostasis? -
Answer: Glucagon & Insulin
Where does glucagon come from and what effect does it have on blood glucose
concentrations? - Answer: Glucagon comes from alpha cells, and it increases blood
glucose concentrations
2
APPHIA - Crafted with Care and Precision for Academic Excellence.
