Biology 212 Self test and homework problems

It's cold outside, but excessively hot in COL 150. Cation X+ is more concentrated on the inside of a cell. Many ions of various types are passing through channels in the membrane. We know from this set of facts that... A. this cell has a negative membrane potential B. cation X has a positive equilibrium potential C. this cell has a positive membrane potential D. cation X has a negative equilibrium potential

D. Cation X has a negative equilibrium potential

The equilibrium potential of sodium in animals is the result of... A. TRPM activity B. leak channel activity C. Piezo1 activity D. the NA/K pump

D. the NA/K pump

True of False: A lion burns less fuel than does a house cat

False

True or False: The sign of driving force tells us the direction driving force will push an ion through a channel, in or out. The magnitude of DF, which you compare on an absolute value basis, tells you how much energy is pushing the ion. The previous questions reveal which ion is being pushed harder, and which is moving faster. We can infer from this that the driving force determines the rate of movement through the membrane

False

True or false: A five pound cat burns less fuel than a % pound snake

False

Where does the Orexin::UCP2 gene construct cause ectopic gene expression to occur? In other words, where is a protein made in a new place because of what the scientists added to mice in the Saper paper?

In the hypothalamus

How does a cation exiting the cell effect membrane potential?

Make membrane potential more negative or less positive

How does an anion entering the cell effect membrane potential?

Makes membrane potential more negative or less positive

Membrane potential is generates by...

Movement of ions through the membrane

When the hypothalamus senses an increase in body temperature it sends signals to various body organs in order to...

Reduce body temperature

The equilibrium potential is a measure of:

Relative (in vs out) concentration of an ion

For Q cells found in the brain the equilibrium potential of "cation B" is 36 mV, the equilibrium potential of "cation D" is -88 mV the resting potential of the cells is -70 mV, and the animal in which these cells are found has a body temperature set point of 38° What is the driving force on "cation B"

-106

What is the driving force acting on sodium during (-70mV) resting potential if it has an equilibrium potential with a magnitude of 108? Notice I say magnitude, but don't say what sign. You need to decide what sign it is.

-178

What is the Vmax of 6.2 concentration of enzyme? Make your answer include 1 decimal place (so 10 would be 10.0 and 11.44 would be 11.4) Graph on other side of flashcard.

12.4

What is the driving force acting on potassium during (-70mV) resting potential if it has an equilibrium potential with a magnitude of 86? Notice I say magnitude, but don't say what sign. You need to decide what sign it is.

16

Beddul is a temperature regulating beast with an aerobic scope of 10, a cost of heating of 12, a maximal metabolic rate of 360 and a lower critical temperature of 18. What is his body temperature?

21

Given an enzyme with a Km for substrate of 12 and a Vmax of 96. What would be the rate of enzyme activity If the concentration of substrate was 5.5 ? Remember Y= Mx + b, and since the origin is part of the linear bit of the graph you are interested in, b= 0

22

For Q cells found in the brain the equilibrium potential of "cation B" is 33 mV, the equilibrium potential of "cation D" is -86 mV the resting potential of the cells is -47 mV, and the animal in which these cells are found has a body temperature set point of 38° What is the driving force on "cation D"

39

The data shown above indicates the enzyme BULASE has a Km of ________. You will need to convert this data into a MM plot to determine the answer. Plot on definition side.

50

What are the rates of PFK and ATP in an animal carrying out metabolic thermogenesis?

A relatively increased PFK activity, but an unchanged ATP synthesis rate

An anion more concentrated inside a cell is the only ion allowed to flow through the membrane. Initially there is no charge across the membrane, but this process generates... A. A positive membrane potential B. A negative equilibrium potential C. A positive equilibrium potential D. A negative membrane potentia

A. A positive membrane potential

A brown fat cell missing the noradrenaline receptor and treated with a toxin that up-regulated AC (adenylate cyclase) would ____________. A cell that was missing AC but had an activated noradrenaline receptor would _______________.

A. Generate heat through increased UCP transcription and activation B. Fail to generate heat

The equilibrium potential of potassium (K+) in an animal cell is negative because that ion is more concentrated A. Inside/Outside of the cell. The resting potential of a typical animal cell is the result of B. TRPM/Funny/Leak/Piezo1 channels allowing potassium to move faster than sodium is allowed to move through the C. Mitochondrial/Cell membrane. The resting potential is therefore negative.

A. Inside B. Leak C. Cell

In a cell in which a receptor causes events leading to the plasma membrane having a significantly greater resistance to potassium than to sodium, the membrane potential of that cell would become A. Less negative/More positive than during resting potential. We don't consider this to be the same as the similar but not identical phrase more positive because the resting membrane potential is B. Positive/Negative

A. Less negative B. Negative

We know that the driving force on chloride related to ionocyte function is A. Positive/negative because we know B. Anions always have a negative driving force/ chloride exiting the cell/ the equilibrium potential of chloride is positive in this setting.

A. Negative B. Chloride is exiting the cell

If you wanted to make brown fat cells express the orexin protein you would engineer the coding region of the orexin gene to the A. Active/regulatory/allosteric/coding region of the B. UCP/PFK/brown fat/allosteric gene

A. Regulatory B. UCP

Alan Hodgkin and Andrew Huxley used squid neurons to update the existing paradigm of how membrane potential changes from resting potential in a cell from simply closing sodium channels to a more complex process of opening and closing A. Sodium and chloride/ potassium and chloride/sodium and potassium channels when they discovered that membrane potential didn't just do to zero during a nerve impulse, it actually becomes B. Restful/ hyperpolarized/positive

A. Sodium and potassium B. Positive

Blocking TRPM activity leads to A. Warmer mice/Cooler mice. TRPM activity increases blood flow B. Generally as an increased pulse/To the tail/To the core which C. Warms/Cools the mouse because D. Metabolic themogensis/ SA/V /increased pressure increased the process.

A. Warmer mice B. To the tail C. Cools D. SA/V

Given the profound result of the Na/K pump, membrane potential in animal cells is a function of... A. the conductance (1/resistance) of particular channels B. The rate of pump activity C. The sum or net of all of the equilibrium potentials of ions in and out of the cell D. The sum or net of all of the driving forces on ions in and out of the cell

A. the conductance (1/resistance) of particular channels

An increase cytoplasmic concentration of AMP/Fructose 1,6 Bis-Phosphate/ATP/UCP2 would lead to an increase in PFK activity

AMP

If green ions are anions and purple ions are cations, which of the following situations would lead to the most positive membrane potential?

Both channel types are open

Which of the following generates resting potential? A. Piezzo 1 & 2 channels B. TRPV1 channels C. Leak channels D. The Na/K pump

C. Leak channels

True or false: A lion burns less fuel per unit size than does a house cat

True

How could you get the UCP2 protein, which is slightly different from the UCP1 protein found in brown fat cells, into brown fat cells? Use a...

UCP1::UCP2 construct

Adding solute to a cell directly ________ osmotic potential and indirectly _________ pressure potential.

decreases, increases

What is the equation for driving force?

membrane potential minus equilibrium potential

Mice that make uncoupler proteins in their hypothalmus are described in the Saper paper. How is this accomplished?

They attached the coding region of an uncoupler gene to the regulatory region of an orexin gene