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CORRECT.
Question 1
Which enzyme is responsible for phosphorylating the glucose molecule after it enters the
beta cell, initiating the process of insulin secretion?
A) Hexokinase
B) Glucokinase
C) Tyrosine kinase
D) Phosphofructokinase
E) Glucose-6-phosphatase
Correct Answer: B) Glucokinase
Rationale: once glucose enters the cell through the glucose transporter, the molecule is
phosphorylated specifically by Glucokinase. This phosphorylation is a crucial step before the
glucose undergoes oxidation in the mitochondria to produce ATP.
Question 2
During the ionic control of insulin secretion, what specific event directly triggers the closing
of the ATP-dependent Potassium (K+) channel?
A) The influx of Calcium ions
B) The phosphorylation of glucose
C) The increase in ATP production via oxidation
D) The binding of insulin to the tyrosine kinase receptor
E) The repolarization of the membrane
Correct Answer: C) The increase in ATP production via oxidation
Rationale: The oxidation of phosphorylated glucose in the mitochondria results in increased
ATP production. This increase in ATP production is the specific signal that causes
the closing of the ATP-dependent K+ channel.
Question 3
What is the final ionic event that causes the exocytosis of insulin vesicles into the blood?
A) Influx of Sodium (Na+)
B) Efflux of Potassium (K+)
C) Influx of Calcium (Ca+) via voltage-gated channels
D) Active transport of Magnesium
E) Chloride shift
Correct Answer: C) Influx of Calcium (Ca+) via voltage-gated channels
Rationale: After the ATP-dependent K+ channels close, voltage changes across the membrane
occur. This depolarization opens the Voltage Gated Calcium channels. The subsequent influx of
calcium is what causes the release of the insulin vesicle into the blood through exocytosis.
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Question 4
In the regulation of glucagon secretion, which channel is opened by the ATP created during
glucose oxidation?
A) ATP-dependent Potassium channel
B) ATP-dependent Sodium channel
C) Voltage-gated Calcium channel
D) Ligand-gated Chloride channel
E) Proton pump
Correct Answer: B) ATP-dependent Sodium channel
Rationale: In the control of glucagon secretion, oxidation creates ATP, which causes ATP-
dependent Sodium channels to open (in contrast to insulin secretion where ATP closes K+
channels). This leads to a change in membrane potential.
Question 5
Which type of receptor does insulin bind to in order to lower blood sugar?
A) G-protein coupled receptor
B) Nicotinic receptor
C) Muscarinic receptor
D) Insulin Tyrosine Kinase Receptor
E) Nuclear receptor
Correct Answer: D) Insulin Tyrosine Kinase Receptor
Rationale: The text explicitly states that insulin binds to the Insulin Tyrosine Kinase Receptor.
This binding recruits glucose transporters to bring glucose into the blood and initiates signal
transduction.
Question 6
Once glucose enters a target cell due to insulin signaling, which of the following is NOT a
potential metabolic fate for that glucose?
A) Stored as Glycogen
B) Broken down into pyruvate through glycolysis
C) Converted to fatty acids
D) Converted directly into protein
E) All of the above are potential fates
Correct Answer: D) Converted directly into protein
Rationale: The provided text lists three specific options for glucose after signal transduction: it
can be stored as Glycogen, broken down into pyruvate through glycolysis, or converted to fatty
acids. Conversion directly to protein is not listed as a pathway for glucose in this context.
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Question 7
Which pancreatic cell type is triggered by glucagon to secrete somatostatin?
A) A-Cells
B) B-Cells
C) D-Cells
D) F-Cells
E) Acinar Cells
Correct Answer: C) D-Cells
Rationale: In the regulation of insulin and glucagon, Glucagon triggers D-Cells to secrete
somatostatin. (Glucagon also triggers B-Cells to secrete insulin).
Question 8
What is the primary function of Pancreatic Polypeptide?
A) To lower blood sugar
B) To raise blood sugar
C) To neutralize stomach acid
D) To regulate pancreatic secretions (endocrine and exocrine)
E) To digest lipids
Correct Answer: D) To regulate pancreatic secretions (endocrine and exocrine)
Rationale: The text defines the function of Pancreatic Polypeptide as regulating pancreatic
secretions, affecting both the endocrine and exocrine functions of the pancreas.
Question 9
Which hormones cause pancreatic Acinar Cells to release Zymogens?
A) Insulin and Glucagon
B) CCK and Acetylcholine (Ach)
C) Secretin and Ach
D) Somatostatin and Pancreatic Polypeptide
E) Cortisol and Aldosterone
Correct Answer: B) CCK and Acetylcholine (Ach)
Rationale: The text states that CCK and Ach cause Acinar Cells to release Zymogens (inactive
enzymes). Secretin and Ach, conversely, cause Centro Acinar cells to secrete bicarbonate.
Question 10
What is the function of the bicarbonate secreted by Centro Acinar Cells?
A) To breakdown proteins
B) To activate Zymogens
C) To neutralize the effects of acid so digestive enzymes can function
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D) To emulsify fats
E) To inhibit insulin secretion
Correct Answer: C) To neutralize the effects of acid so digestive enzymes can function
Rationale: Secretin and Ach stimulate Centro Acinar Cells to secrete Bicarbonate,
which neutralizes the effects of acid (from the stomach) to create the optimal pH for digestive
enzymes to function.
Question 11
Which hormone stimulates the Adrenal Cortex to produce corticosteroids?
A) CRH
B) ACTH
C) TSH
D) FSH
E) Epinephrine
Correct Answer: B) ACTH
Rationale: The text states that ACTH (Adrenocorticotropic Hormone) acts on the adrenal cortex
to produce corticosteroids. CRH stimulates the release of ACTH, but ACTH is the direct
stimulator of the cortex.
Question 12
The adrenal medulla is stimulated by which system to produce epinephrine and
norepinephrine?
A) The Somatic Nervous System
B) The Parasympathetic Nervous System
C) The Autonomic Nervous System
D) The Renin-Angiotensin System
E) The Enteric Nervous System
Correct Answer: C) The Autonomic Nervous System
Rationale: The Autonomic Nervous System (specifically pre-ganglionic sympathetic neurons)
stimulates the adrenal medulla to release catecholamines.
Question 13
Chromaffin cells in the adrenal medulla convert which amino acid into epinephrine and
norepinephrine?
A) Phenylalanine
B) Tryptophan
C) Tyrosine
D) Glutamine
E) Leucine