Chapter 7 concept questions Flashcards
Name the membrane transport process by which glucose moves from the extracellular fluid into cells.
facilitated diffusion (GLUT transporters)
What is the suffix in a chemical name that tells you a molecule is an enzyme?[Hint: p. 101] Use that suffix to name an enzyme that digests peptides.
-ase indicates an enzyme. A peptidase digests peptides.
What is the classic definition of a hormone?
A chemical secreted into the blood that acts on a distant target in very low concentrations
Based on what you know about the organelles involved in protein and steroid synthesis[p. 65], what would be the major differences between the organelle composition of a steroid-producing cell and that of a protein-producing cell?
steroid-producing cell: extensive smooth endoplasmic reticulum, protein-producing cell: lots of rough endoplasmic reticulum and secretory vesicles
What are the three chemical classes of hormones?
peptide, steroid, and amino acid-derived
The steroid hormone aldosterone has a short half-life for a steroid hormone—only about 20 minutes. What would you predict about the degree to which aldosterone is bound to blood proteins?
The short half-life suggests that aldosterone is not bound to plasma proteins as much as other steroid hormones are.
In the blood glucose example, the increase in blood glucose corresponds to which step of a reflex pathway? Insulin secretion and the decrease in blood glucose correspond to which steps?
Increased blood glucose is the stimulus. Insulin secretion is the efferent pathway; decrease in blood glucose is the response.
Which insulin release pathway in Figure 7.7b is a simple endocrine reflex? Which is a complex endocrine reflex? Which is a combination neural-endocrine reflex?
Insulin release by blood glucose is a simple endocrine reflex. Insulin release in response to a digestive hormone is the complex endocrine reflex. Insulin release triggered by a neural signal following a meal is the neural-endocrine reflex.
Glucagon is released from alpha cells in the pancreas when blood glucose levels decrease. Glucagon acts on multiple target tissues to increase blood glucose. Draw a reflex pathway to match this description.
stimulus: decreased blood glucose, sensor/integrating center: pancreatic endocrine cells, efferent path: glucagon, target: multiple target tissues, response: increased blood glucose
Catecholamines belong to which chemical class of hormone?
amino acid-derived hormones
What intracellular structure is used for transport of secretory vesicles within the cell?
Microtubules of the cytoskeleton move secretory vesicles.
Name the membrane process by which the contents of secretory vesicles are released into the extracellular fluid.
Contents released by exocytosis.
Match thegeneral reflex pathway patterns shown in Figure 6.19 [p. 189 patterns of the homeostatic reflex pathways] to:
a. the hypothalamic neurohormone—prolactin—breast pattern just described
b.the growth hormone pathway in Figure 7.10
(a) pathway 4
(b) pathway 4 for GH acting directly on targets, and pathway 5 for GH acting on the liver
What is the target tissue of a hypothalamic neurohormone secreted into the hypothalamic-hypophyseal portal system?
The target is endocrine cells of the anterior pituitary.
