formative quiz 1

Question 1

In which cell organelle do you see the beginning of glycosylation?

Answer 1

Rough Endoplasmic Reticulum

Question 2

Choose the correct response regarding primary lysosomes.

Answer 2

Contain enzymes with optimal activity at pH 5

Question 3

Microtubules organized as triplets are called?

Answer 3

Basal body

Question 4

A researcher develops a drug that caused detachment of cells from their basement membrane. Which type of cell
junction is most likely affected by this drug?

Answer 4

Hemidesmosomes

Question 5

In a normal 70 Kg man, a tracer (indicator) was used to measure a body fluid compartment, using the dilution
principle. The volume of distribution of this tracer was found to be 14 L. Of the following tracers, the most likely
one used in this case is:

Which body fluid compartment was measured

Answer 5

Inulin

the question provides body weight (70 kg) and a measure of volume (14 Liters) with a tracer using the
indicator dilution technique. Approach to the problem: the volume 14 liters represents a compartment, but which
one? 14 liters/70 kg = 0.2 or 20% of the body weight which would correspond most likely to the ECF volume. Given
the choices of tracers, only choice B Inulin is a marker for the ECF volume. The other tracers are used to estimate
other body fluid compartments

ECF

Question 6

In a certain tissue-organ system, the average capillary hydrostatic pressure at the arteriolar end is 22 mm Hg, the
plasma oncotic pressure is 25 mm Hg, the interstitial fluid oncotic pressure is 6 mm Hg, and interstitial fluid
hydrostatic pressure is 6 mm Hg below atmospheric pressure. The net result is a pressure of ______ forcing water
______the capillaries

Answer 6

9 mm, out of

The concept being examined in this question is the balance of Starling forces across a capillary (or net
filtration pressure). You can do this either by assessing the forces that drive fluid OUT of the capillary (capillary
hydrostatic and interstitial oncotic) and the forces that drive fluid INTO the capillary (capillary oncotic and interstitial
hydrostatic) and see which is greater (i.e. is fluid moving into or out of the capillary). Pressure below atmospheric
suggests a negative pressure (as suction created when drinking with a straw).

Question 7

The major difference between hormones that have intracellular/nuclear receptors and those that have cell
membrane receptors is that the former tend to be

Answer 7

Hydrophobic

Intracellular receptors like nuclear receptors rely on signaling molecules that can pass through the
hydrophobic membrane.

Question 8

Increasing the temperature always shifts the equilibrium by increasing the reaction
in the endothermic direction.) This is an SN2 nucleophilic substitution reaction in which one phosphoester bond is
severed and its energy is used to form a new phosphoester bond. As increase in temperature shifts the reaction to the
left (toward Y and X-phosphate), the enthalpic energy associated with the Y-phosphate bond must not be sufficient to
make the X-phosphate bond, requiring energy from heat at the ambient temperature to be absorbed to make up for the
deficit. The increase in temperature is increasing the reservoir of energy available to make up for the deficit, shifting
the equilibrium toward the left. Thus, A) is the correct answer

Question 9

In a nerve cell, the concentration of K+ inside the cell is higher than outside. The resting membrane potential (that is, a
voltage gradient inside versus outside across the plasma membrane) is established by the movement of K+ from inside
to outside, a process associated with an increase in entropy (i.e., ∆S has a positive value). This process:

Answer 9

must be endothermic

Establishment of a voltage gradient requires input of energy as this involves the separation of opposite
charges (a process that requires application of force). The movement of K+ down the concentration gradient (∆S is
positive) can be fueled by thermal energy (which would be absorbed from the surroundings of the reaction system).
Thermal energy can be converted to electrical potential according to the first law of thermodynamics (heat and work
to establish an electrical gradient are interconvertible), ∆H for the process having a positive value (an endothermic
reaction). So long as T∆S has a value greater than ∆H, then ∆G = ∆H - T∆S would have a negative value and the
process can occur spontaneously.