BIO201 Homework #5 (Lectures 13-15)

G-protein coupled receptors have ____ transmembrane domains. - 1 - 2 - 5 - 7

7

If you had a patient in which the lung epithelium was leaking fluids from the bloodstream into the lumen of the lung, which of the following is the most likely cause? - A mutation in a cell adhesion molecule - A mutation in an extracellular matrix protein - High levels of cholesterol - A mutation in actin

A mutation in a cell adhesion molecule

If it were injected directly into liver cells, cAMP would have the effect of: - Catalyzing the hydrolysis of GTP. - None of the above; nothing would happen in the absence of the "first messenger" - Activating G-alpha. - Activating Protein Kinase A and, therefore, glycogen breakdown

Activating Protein Kinase A and, therefore, glycogen breakdown

Which of the following is a disadvantage of being multicellular? - Greater energy needs - More difficult to absorb nutrients - Reproduction more complicated - All of the above

All of the above

Which of the following is NOT TRUE of a second messenger in signal transduction? - It is diffusible - It is produced when the "first messenger" binds to its receptor - It may activate enzymes - All of the above are TRUE

All of the above are TRUE

Which adaptation specific to becoming multicellular compensates for the destabilizing effect of increased size? (Think carefully about answer choices!) - Extracellular matrix - Tight junctions - Cytoskeleton - Both ECM and tight junctions - All of the above

Both ECM and tight junctions

Which of the following is/are likely to elicit a slow, but long-lasting or even permanent cellular response? - An odorant that binds to a G protein-coupled receptor - A growth factor that binds to a receptor tyrosine kinase - A steroid hormone - Both growth factor signaling and steroid hormone signaling

Both growth factor signaling and steroid hormone signaling

Which of the following is a disadvantage of being a multicellular organism? - Decreased mobility - Cellular specialization - Decreased structural stability - All of the above

Decreased structural stability

One of the main differences between growth factor signaling (receptor tyrosine kinase receptors) and epinephrine signaling (G-protein coupled receptors) is that: - Epinephrine signaling involves enzyme cascades, while growth factor signaling does not. - Epinephrine signaling is more likely to have a short-term, reversible effect. - Only epinephrine signaling involves a GTPase. - Only epinephrine signaling involves kinase activity.

Epinephrine signaling is more likely to have a short-term, reversible effect.

Ca++ flowing down its concentration gradient through a Ca++ channel is an example of: - Simple diffusion. - Facilitated diffusion. - Indirect active transport. - Direct active transport.

Facilitated diffusion

Unlike in animals, in which the Na+ gradient is used, it is the H+ gradient in some other species that fuels transport of other compounds up their concentration gradients. This type of transport is: - Indirect active transport - Direct active transport - Facilitated diffusion - Simple diffusion

Indirect active transport

Which of the following is an advantage of endocrine signaling? - It affects large numbers of cells. - It is fast. - All of the above - It can be bidirectional.

It affects large numbers of cells.

Which of the following can be considered both an advantage and a disadvantage of juxtacrine signaling? - It affects only one or a very small number of cells. - All of the above - It doesn't produce a second messenger. - It is slow.

It affects only one or a very small number of cells.

What happens to GTP in response to epinephrine binding to its receptor on liver cells? - It falls off of G-alpha - It gets phosphorylated - It is hydrolyzed - It binds to G-alpha

It binds to G-alpha

Whooping cough, also known as pertussis, is caused by the bacterium Bordetella pertussis. Some of its effects result from production of Pertussis toxin, which prevents Gα from binding to G-protein coupled receptors, and thereby "locking" Gα in the GDP-bound state. If you treated liver cells with Pertussis toxin, how would it affect liver cell responses to epinephrine? - It would increase glucose production. - It would decrease proliferation. - It would decrease secretion of digestive enzymes. - It would increase proliferation. - It would decrease glucose production.

It would decrease glucose production

Chloride ion (Cl-) concentrations must be maintained much higher outside of cells than inside of cells. How this gradient is maintained is complex, but a key transporter co-transports Cl- along with K+ ions. The name of this transport protein could be ____ and its mode of transport would be ____. - Na+/K+ ATPase; direct active transport - K+/Cl- symporter; indirect active transport - K+/Cl- antiporter; indirect active transport - Na+/Cl- antiporter; indirect active transport

K+/Cl- symporter; indirect active transport

Which of the following is a disadvantage of being a multicellular organism specifically as opposed to unicellular? (read and think carefully!) - Increased mobility - More difficult to absorb nutrients - Loss of peptidoglycan reduces stability - All of the above

More difficult to absorb nutrients

Chloride ion (Cl-) concentrations are approximately 10x higher outside of cells than inside. Imagine you discovered a novel protein that is required in liver cells for transporting Cl- out of the cell up its concentration gradient, and further found that this protein only functions if the Na+/K+ ATPase is active. This suggests that the Cl- transport protein is a: - Cl- ATPase - K+/Cl- antiporter - Na+/Cl- antiporter - Cl- channel

Na+/Cl- antiporter

Chloride ion (Cl-) concentrations are approximately 10x higher outside of cells than inside. Imagine you discovered a novel protein that is required in liver cells for transporting Cl- out of the cell up its concentration gradient, and further found that this protein only functions if the Na+/K+ ATPase is active. This suggests that the Cl- transport protein is a: - Na+/Cl- antiporter - Cl- ATPase - K+/Cl- antiporter - Cl- channel

Na+/Cl- antiporter

"During embryonic development red blood cells begin to develop in patches called blood islands. The blood cells secrete growth factors that diffuse only to nearby cells, signaling differentiation into endothelial cells. The endothelial cells eventually form the linings of the blood vessels." The growth factor described in the passage is involved in what type of signaling? - Juxtacrine - Paracrine - Autocrine - Endocrine

Paracrine

A major function of the epithelium in animals is to prevent entry of pathogens and toxins from the environment. Which of the following is common to all epithelial cells? - They are found entirely on the outside of the body, e.g. skin, but not internally, like in the intestines or lungs. - They are ciliated. - They secrete digestive enzymes. - They are held together by tight junctions.

They are held together by tight junctions.

Which of the following is true of both GPCR signaling and steroid hormone signaling? - They both involve intracellular receptors. - They may result from endocrine signals. - Both effects are rapid and reversible. - They both involve enzyme cascades.

They may result from endocrine signals.

Cell adhesion molecules are important components of: - plant cell walls - bacterial cell walls - Tight junctions - Extracellular matrix

Tight junctions

The Na+/K+ ATPase transports Na+ up its concentration gradient and K + ______ its concentration gradient. This is an example of ______ . - Up; Direct active transport - Up; Indirect active transport - Down; facilitated diffusion - Down; facilitated diffusion - Down; indirect active transport

Up; Direct active transport

Liver cells respond to epinephrine by breaking down glycogen. What is the second messenger in this patway? - the G-protein - cyclic AMP - GTP - Protein kinase A

cyclic amp

True or False: The concentration of K+ outside the cell is higher than it is inside.

false

True or False: The concentration of Na+ inside the cell is higher than it is outside.

false

Collagen, an extremely important extracellular matrix protein, is constitutively secreted by fibroblast cells, a type of connective tissue cell. If you had a patient in which collagen is synthesized normally, but fails to be secreted into the extracellular matrix, which of the following would you examine as the likely cause of this problem? (Think very carefully before answering this question!) - Ca++ deficiency - failure of the Na+/K+ ATPase - H+ pump disorder - kinesin disorder

kinesin disorder

True or False: The concentration of Na+ outside the cell is higher than it is inside.

true