Bio E109 Midterm 1 Review Questions and Answers
Question 1.
Antiport
Correct Answer: two substances move in opposite directions
Question 2.
Where is water flowing in terms of diffusion?
Correct Answer: It always flows in the direction of more solutes.
Question 3.
What is osmosis?
Correct Answer: diffusion of water specifically (from areas of low osmolarity to
high osmolarity)
Question 4.
What is antagonism?
Correct Answer: an agonist activates receptors (mimics ligand) while an
antagonist blocks receptors (no response)
Question 5.
What does the cell actively do internally and externally?
Correct Answer: External: maintain homeostasis Internal: chemical
disequilibrium
Question 6.
What are two types of long distance communication?
Correct Answer: endocrine and neurohormones
Question 7.
Why is the rate of diffusion directly proportional to lipid solubility rather than water
solubility?
Correct Answer: The cell membrane is made up of lipids/lipid bilayer.
Question 8.
How do you know which ion is the cell most permeable to?
Correct Answer: The ion with the Eion closest to the cell's membrane potential is
the most permeable.
Question 9.
What is a gap junction?
Correct Answer: channels that physically connect two cells together (can share
membrane potential)
Question 10.
Extracellular fluid (plasma and interstitial fluid) has a high concentration of what?
Correct Answer: High concentration of Na+ and Cl-
, Question 11.
What is a steroid hormone?
Correct Answer: - cholesterol serves as the parent compound - lipid soluble -
require a protective carrier
Question 12.
The rate of diffusion is directly proportional to what?
Correct Answer: surface area x concentration gradient x membrane permeability
Question 13.
What is autocrine?
Correct Answer: cell releases a signaling molecule that it receives itself
Question 14.
What is contact dependent signaling?
Correct Answer: cells need to be touching each other
Question 15.
Intracellular fluid has a high concentration of what?
Correct Answer: High concentration of K+ (and proteins)
Question 16.
What aspect of the hormone signaling makes it efficient for rapid responses?
Correct Answer: short half life
Question 17.
What is negative feedback?
Correct Answer: when the response of a pathway inhibits that same pathway
(ex: insulin)
Question 18.
Secondary transport carries how many molecules? How about primary?
Correct Answer: - Secondary carries 2 while primary carries only 1 molecule
Question 19.
What is positive feedback?
Correct Answer: when the response of a pathway promotes that same pathway
(ex: contractions during childbirth)
Question 20.
What is the resting membrane potential?
Correct Answer: - 70 mV
Question 21.
What is mass balance measured in?
Correct Answer: moles or volume (NEVER CONCENTRATION)
Question 1.
Antiport
Correct Answer: two substances move in opposite directions
Question 2.
Where is water flowing in terms of diffusion?
Correct Answer: It always flows in the direction of more solutes.
Question 3.
What is osmosis?
Correct Answer: diffusion of water specifically (from areas of low osmolarity to
high osmolarity)
Question 4.
What is antagonism?
Correct Answer: an agonist activates receptors (mimics ligand) while an
antagonist blocks receptors (no response)
Question 5.
What does the cell actively do internally and externally?
Correct Answer: External: maintain homeostasis Internal: chemical
disequilibrium
Question 6.
What are two types of long distance communication?
Correct Answer: endocrine and neurohormones
Question 7.
Why is the rate of diffusion directly proportional to lipid solubility rather than water
solubility?
Correct Answer: The cell membrane is made up of lipids/lipid bilayer.
Question 8.
How do you know which ion is the cell most permeable to?
Correct Answer: The ion with the Eion closest to the cell's membrane potential is
the most permeable.
Question 9.
What is a gap junction?
Correct Answer: channels that physically connect two cells together (can share
membrane potential)
Question 10.
Extracellular fluid (plasma and interstitial fluid) has a high concentration of what?
Correct Answer: High concentration of Na+ and Cl-
, Question 11.
What is a steroid hormone?
Correct Answer: - cholesterol serves as the parent compound - lipid soluble -
require a protective carrier
Question 12.
The rate of diffusion is directly proportional to what?
Correct Answer: surface area x concentration gradient x membrane permeability
Question 13.
What is autocrine?
Correct Answer: cell releases a signaling molecule that it receives itself
Question 14.
What is contact dependent signaling?
Correct Answer: cells need to be touching each other
Question 15.
Intracellular fluid has a high concentration of what?
Correct Answer: High concentration of K+ (and proteins)
Question 16.
What aspect of the hormone signaling makes it efficient for rapid responses?
Correct Answer: short half life
Question 17.
What is negative feedback?
Correct Answer: when the response of a pathway inhibits that same pathway
(ex: insulin)
Question 18.
Secondary transport carries how many molecules? How about primary?
Correct Answer: - Secondary carries 2 while primary carries only 1 molecule
Question 19.
What is positive feedback?
Correct Answer: when the response of a pathway promotes that same pathway
(ex: contractions during childbirth)
Question 20.
What is the resting membrane potential?
Correct Answer: - 70 mV
Question 21.
What is mass balance measured in?
Correct Answer: moles or volume (NEVER CONCENTRATION)
