1 | Page
Chamberlain University-Illinois
BIOS 252
Exam 3 Study Guide Questions and Answers
2026 Latest Update
What is endocrinology? Ans: The study of systems that regulate endocrine
glands and hormones
What is the primary goal of the endocrine system? Ans: Maintain
homeostasis
What is a hormone? Ans: A chemical messenger released into the
bloodstream to act on distant target cells
What are target cells? Ans: Cells that respond to hormones via specific
receptors
How do hormones exert their effects? Ans: By binding to specific receptors
Hormone-receptor binding is what type of interaction? Ans: Non-covalent
Where can hormone receptors be located? Ans: Plasma membrane,
cytoplasm, or nucleus
What determines hormone specificity? Ans: The receptor recognizing a
hormone's unique 3D structure
What is an agonist? Ans: A substance that binds to and activates a receptor
What is an antagonist? Ans: A substance that binds to a receptor but does
not activate it
What determines the magnitude of a hormone's response? Ans: Number of
hormone-receptor complexes
What is free hormone concentration? Ans: Hormone not bound to plasma
proteins
© 2026 All rights reserved
, 2 | Page
What does receptor saturation mean? Ans: All receptors are occupied
What is hormone half-life? Ans: Time required for hormone concentration to
decrease by half
What is receptor desensitization? Ans: Reduced response due to receptor
overactivation
What is homologous desensitization? Ans: Reduced response caused by the
same hormone
What is heterologous desensitization? Ans: Reduced response caused by a
different hormone
What most commonly changes hormone response magnitude? Ans: Rate of
hormone secretion
What is negative feedback? Ans: A response that returns a variable toward
its set-point
What is positive feedback? Ans: A response that amplifies the stimulus
What are counter-regulatory hormones? Ans: Hormones with opposing
effects on the same variable
What are trophic hormones? Ans: Hormones that stimulate growth or
secretion of another endocrine gland
What is hormone synergy? Ans: Combined hormonal effect greater than the
sum of individual effects
Are peptide hormones hydrophilic or lipophilic? Ans: Hydrophilic
How are peptide hormones secreted? Ans: Calcium-dependent exocytosis
Do peptide hormones require transport proteins? Ans: No
Do peptide hormones have short or long half-lives? Ans: Short
What do second messengers do? Ans: Amplify hormone signals
List major second messengers Ans: cAMP, cGMP, IP3, DAG, Calcium
What are steroid hormones synthesized from? Ans: Cholesterol
© 2026 All rights reserved
Chamberlain University-Illinois
BIOS 252
Exam 3 Study Guide Questions and Answers
2026 Latest Update
What is endocrinology? Ans: The study of systems that regulate endocrine
glands and hormones
What is the primary goal of the endocrine system? Ans: Maintain
homeostasis
What is a hormone? Ans: A chemical messenger released into the
bloodstream to act on distant target cells
What are target cells? Ans: Cells that respond to hormones via specific
receptors
How do hormones exert their effects? Ans: By binding to specific receptors
Hormone-receptor binding is what type of interaction? Ans: Non-covalent
Where can hormone receptors be located? Ans: Plasma membrane,
cytoplasm, or nucleus
What determines hormone specificity? Ans: The receptor recognizing a
hormone's unique 3D structure
What is an agonist? Ans: A substance that binds to and activates a receptor
What is an antagonist? Ans: A substance that binds to a receptor but does
not activate it
What determines the magnitude of a hormone's response? Ans: Number of
hormone-receptor complexes
What is free hormone concentration? Ans: Hormone not bound to plasma
proteins
© 2026 All rights reserved
, 2 | Page
What does receptor saturation mean? Ans: All receptors are occupied
What is hormone half-life? Ans: Time required for hormone concentration to
decrease by half
What is receptor desensitization? Ans: Reduced response due to receptor
overactivation
What is homologous desensitization? Ans: Reduced response caused by the
same hormone
What is heterologous desensitization? Ans: Reduced response caused by a
different hormone
What most commonly changes hormone response magnitude? Ans: Rate of
hormone secretion
What is negative feedback? Ans: A response that returns a variable toward
its set-point
What is positive feedback? Ans: A response that amplifies the stimulus
What are counter-regulatory hormones? Ans: Hormones with opposing
effects on the same variable
What are trophic hormones? Ans: Hormones that stimulate growth or
secretion of another endocrine gland
What is hormone synergy? Ans: Combined hormonal effect greater than the
sum of individual effects
Are peptide hormones hydrophilic or lipophilic? Ans: Hydrophilic
How are peptide hormones secreted? Ans: Calcium-dependent exocytosis
Do peptide hormones require transport proteins? Ans: No
Do peptide hormones have short or long half-lives? Ans: Short
What do second messengers do? Ans: Amplify hormone signals
List major second messengers Ans: cAMP, cGMP, IP3, DAG, Calcium
What are steroid hormones synthesized from? Ans: Cholesterol
© 2026 All rights reserved
