BIOL 2160 - exam 2 answers

Which of the following will cross the membrane through simple diffusion?

a hydrophobic molecule

The energy required during active transport is needed to

move molecules from low to a high concentration

A decrease in solute concentration will __________ energy

decrease

Which of the following is FALSE

there is more Na+ inside the cell than outside

In a normal cell at rest, the electrical driving force wants to move K+/Na+ __________ the cell

into

In a normal cell at rest, the chemical driving force wants to move K+ _________ the cell

out of

In a normal cell at rest, the chemical driving force wants to move Na+ __________ the cell

into

If you were told that a given cell has a resisting membrane potential of +40mV. What conclusion could you draw about the cell?

the cell is more permeable to Na+ at rest than it is to K+

If you were told that a given cell has a resisting membrane potential of -40mV. What conclusion could you draw about the cell?

the cell is more permeable to K+ at rest than it is to Na+

In a normal cell at rest, which driving force has a strong effect on K+?

chemical

For a normal cell, if the membrane potential were 0mV, you would expect Na+ to:

move into the cell

For a normal cell, if the membrane potential were 0mV, you would expect K+ to:

move out the cell

For a normal cell, if the membrane potential were -100mV, you would expect K+/Na+ to:

move into the cell

If a cell has a membrane potential of -65mV, what does this mean?

the inside of the cell is 65mV more negative than the outside

Which of the following is an example of countertransport?

Na+ moves in the cell and H+ (glucose) moves out the cell

Why is energy needed for the Na+/K+ ATPase?

both A and B

Solution A has a concentration of 3M glucose. Solution B has a concentration of 8M glucose. Which solution has less free water?

solution A

Osmosis is always a passive process

true

If a cell were placed in a solution and the mass of the cell increased, which of the following must be true?

the intracellular solution is hypersomatic to the extracellular solution

If a cell with a 2M internal sucrose concentration were places in a 5M sucrose solution, what would you expect to happen?

the cell would shrivel up

A non-specific, large, liquid molecule would most likely enter the cell through which process?

Pinocytosis

Some depression medication block which process?

receptor-mediated endocytosis

Which of the following is not an example of a passive transport mechanism?

Na+/K+ ATPase

Which of the following chemical messengers travels the greatest difference?

hormones

Which of the following will not be bound to carrier proteins in the bloodstream?

hydrophilic messengers

Where would you expect to find a receptor for a hydrophobic messenger?

on the cell membrane

________ is a measure of attraction between ligands and receptors

affinity

A ligand that binds a receptor and does not cause a biological response is called

antagonist

Hormones enter the bloodstream

true

A receptor that has kinase activity is most likely an

enzyme linked receptor

Which of the following is not one of the subunits of a typical G protein?

delta

An activated G protein will have ________ bound to it. (repeated question)

GTP

Which of the following ion channels typically stay open longest?

G protein-regulated ion channels

The most common cellular response for lipophilic hormone is

change in protein synthesis

How are neurotransmitters different than paracrines?

neurotransmitters are only produced by neurons

Where would you expect to find a receptor for a steroid hormone?

inside the cell

What type of communication is gap junctions?

direct

What type of protein is p53?

transcription factor

What does p21 do?

blocks cyclin-dependent kinase inhibitors

According to the article "John Rock's Error", what factors most greatly contributed to the substantially lower incidence of breast cancer among Asian women when compared to American women?

weight differences, ex: post-menopausal American women are substantially heavier than Asian women

Which of the following hormones, in healthy women, prevents ovulation and establishes pre - and post - menstrual "safe" period?

progesterone/progestin

Strassman's research on the Dogon tribe in Mali concluded that the women in this tribe menstruate, on average, _______ times less than Western women of the same age.

the answer with "ovulation is less"

How many mutations are needed for most cancers to occur?

5-6

How does HPV cause cervical cancer?

a viral protein causes dimerization of PDGF receptors

RasD leaves genes in the ________ position for too long.

ON

Tissues that secrete inhibitors of proteolytic enzymes will be _______ resistant to metastasis.

more

Which HPV protein can bind to PDGF receptors, causing sustained cell division?

E5

Anti-angiogenesis drugs are used to do which of the following?

prevent development of new blood vessels

Why is G1 checkpoint in the cell cycle so important?

because it is the only checkpoint that occurs before DNA replication

What does Tamoxifen do?

blocks estrogen receptors (answer was just blocks)

Why are cancer patients sometimes given erythropoietin?

to stimulate red blood cell division

Which is a characteristic of a transformed cancer cell?

they have fewer actin microfilaments