Q: A cell is actively transporting sodium ions ($$\mathrm{Na^+}) $$out and potassium ions ($$\mathrm{K^+}) in$$, both against their concentration gradients. Which equation best represents the energy requirement for this process?

$$\mathrm{ATP} \rightarrow \mathrm{ADP} + \mathrm{P_i} + \text{energy}$$

Question 1

Which of the following best describes the structure of the plasma membrane according to the fluid mosaic model?

Accepted Answer

A double layer of phospholipids with proteins and cholesterol molecules scattered throughout, allowing lateral movement.

Question 2

A cell is placed in a solution and water moves into the cell, causing it to swell. Which type of solution is the cell in, and what is the direction of osmosis?

Accepted Answer

The cell is in a hypotonic solution; water moves into the cell.

Question 3

Which organelle is primarily responsible for the production of ATP through aerobic respiration?

Accepted Answer

Mitochondrion

Question 4

A patient with severe burns loses large amounts of fluids and ions from damaged cells. Which property of the plasma membrane is compromised in this scenario?

Accepted Answer

Selective permeability

Question 5

Which of the following best explains why facilitated diffusion is necessary for glucose transport across the plasma membrane?

Accepted Answer

Glucose is a large, polar molecule that requires a carrier protein to cross the hydrophobic core of the membrane.

Question 6

Which type of membrane protein is directly involved in cell-to-cell recognition and immune response?

Accepted Answer

Glycoprotein

Question 7

A cell is actively transporting sodium ions ($$\mathrm{Na^+}) $$out and potassium ions ($$\mathrm{K^+}) in$$, both against their concentration gradients. Which equation best represents the energy requirement for this process?

Accepted Answer

$$\mathrm{ATP} ightarrow \mathrm{ADP} + \mathrm{P_i} + 	ext{energy}$$

Question 8

Which of the following scenarios best illustrates the function of tight junctions between epithelial cells?

Accepted Answer

Preventing digestive enzymes from leaking between cells lining the intestine.

Question 9

Which of the following is a function of the Golgi apparatus in protein processing?

Accepted Answer

Modifying, sorting, and packaging proteins for secretion or delivery to other organelles.

Question 10

A cell engulfs a bacterium by wrapping its plasma membrane around it and forming a vesicle. What is this process called?

Accepted Answer

Phagocytosis

Question 11

Which cytoskeletal element is primarily responsible for maintaining cell shape and resisting tension?

Accepted Answer

Intermediate filaments

Question 12

A mutation causes the glycocalyx of a cell to change rapidly, making it unrecognizable to the immune system. What is a likely consequence of this mutation?

Accepted Answer

The cell may evade immune detection and continue to replicate, potentially leading to cancer.

Question 13

Which of the following best describes the difference between simple diffusion and facilitated diffusion?

Accepted Answer

Simple diffusion involves movement of small, nonpolar molecules directly through the lipid bilayer, while facilitated diffusion requires membrane proteins for larger or polar molecules.

Question 14

Which of the following is a real-life example of secondary active transport in human physiology?

Accepted Answer

The sodium-glucose symporter in the intestinal epithelium, which uses the sodium gradient established by the Na+/K+ pump to transport glucose into the cell.

Question 15

Which of the following equations best represents the relationship between hydrostatic pressure and osmotic pressure at equilibrium during osmosis?

Accepted Answer

$$P_{hydrostatic} = P_{osmotic}$$

Question 16

Which of the following best describes the function of peroxisomes in the cell?

Accepted Answer

They detoxify harmful substances and break down fatty acids using hydrogen peroxide.

Question 17

A scientist observes that a certain protein is embedded in the plasma membrane and acts as a receptor for insulin. What is the most likely function of this protein?

Accepted Answer

It binds insulin and initiates a signal transduction pathway inside the cell.

Question 18

Which of the following best explains why the nuclear envelope is considered a double membrane structure?

Accepted Answer

It has two lipid bilayers separated by a perinuclear space, each with its own set of proteins and nuclear pores.

Question 19

Which of the following best describes the fate of proteins synthesized on ribosomes bound to the rough endoplasmic reticulum?

Accepted Answer

They are modified and sorted in the Golgi apparatus for secretion, incorporation into membranes, or delivery to lysosomes.

Chapter 3: Cells – The Living Units (Anatomy & Physiology Study Notes)

Guida di studio - Domande di pratica

Study guide - Flashcard