Cell Structure and Function：練習題

A cell is placed in a solution that has a higher solute concentration than the cell's cytoplasm. In which direction will the net movement of water occur, and what is the tonicity of the solution relative to the cell?

A specific toxin inhibits the function of the Golgi apparatus in a eukaryotic cell. Which of the following processes would be most directly and immediately inhibited by the presence of this toxin?

A plant cell with a solute potential (\(\psi_s\)) of \(-0.7\) MPa and a pressure potential (\(\psi_p\)) of \(0.2\) MPa is placed in an open beaker containing a \(0.3\) M sucrose solution at \(25^{\circ}\text{C}\). Given the formula for solute potential \(\psi_s = -iCRT\) (where \(i = 1\), \(R = 0.00831\) L\(\cdot\)MPa/mol\(\cdot\)K), in which direction will net water movement occur?

Which of the following organelles is primarily responsible for the synthesis of lipids and the detoxification of various poisons within a eukaryotic cell?

As a spherical cell increases in size, the ratio of its surface area to its volume changes. If the radius of a cell doubles, how does the surface area-to-volume ratio change, and what is the primary biological consequence of this change?

Which organelle is responsible for the synthesis of lipids and the detoxification of chemicals within a eukaryotic cell?

Explain why the presence of cholesterol in the plasma membrane is essential for maintaining membrane fluidity in human cells when exposed to a significant decrease in environmental temperature.

What is the primary function of the nucleolus found within the nucleus of a cell?

Cells are the fundamental units of life and contain various organelles with specific functions.
a) Name the organelle that is responsible for ATP production via aerobic respiration.
b) Describe the primary function of ribosomes within a cell.
c) Explain why the plasma membrane is described as 'selectively permeable'.

A researcher is studying the transport of glucose across the cell membrane of intestinal epithelial cells. She observes that glucose moves into the cell even when the extracellular concentration of glucose is lower than the intracellular concentration. This process requires a sodium-glucose cotransporter protein and a sodium-potassium pump.

(a) Identify the specific type of transport mechanism being used to move glucose into the cell and justify your answer.
(b) Describe the direct role of ATP in maintaining the concentration gradient necessary for this glucose transport to continue.
(c) Predict what would happen to the rate of glucose transport if a drug that inhibits the sodium-potassium pump is added to the system. Explain your reasoning.