Question 1

Which of the following structures is found in both prokaryotic and eukaryotic cells and is primarily responsible for protein synthesis?

Accepted Answer

Ribosome

Question 2

A scientist is studying the transport of mRNA from the nucleus to the cytoplasm in a eukaryotic cell. Through which structure does the mRNA exit the nucleus, and what is the main mechanism for this transport?

Accepted Answer

Through nuclear pores by active transport

Question 3

Which of the following best describes the function of the Golgi apparatus in the endomembrane system?

Accepted Answer

Modifies, sorts, and packages proteins for secretion or delivery to other organelles

Question 4

During receptor-mediated endocytosis, which of the following occurs?

Accepted Answer

The cell forms vesicles around specific molecules bound to receptors on the plasma membrane

Question 5

Which of the following cell-cell connections allows the direct transfer of ions and small molecules between adjacent animal cells?

Accepted Answer

Gap junctions

Question 6

A plant cell is placed in a solution containing a signaling molecule. The molecule binds to a receptor on the cell surface, activating a G-protein, which then triggers the production of a second messenger. Which type of receptor is involved in this process?

Accepted Answer

G-protein-coupled receptor

Question 7

Which equation correctly represents the relationship between Gibbs free energy ($$\Delta G$$), enthalpy ($$\Delta H$$), entropy ($$\Delta S$$), and temperature ($$T$$)?

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$

Question 8

A reaction has $$\Delta G = -15 kJ/$$mol. Which of the following statements is true about this reaction?

Accepted Answer

The reaction is exergonic and spontaneous

Question 9

In cellular respiration, which step produces the most ATP, and where does it occur in a eukaryotic cell?

Accepted Answer

Electron transport chain in the inner mitochondrial membrane

Question 10

A patient is experiencing muscle fatigue due to low oxygen levels. Which metabolic pathway is most likely being used to generate ATP in their muscle cells, and what is a byproduct of this pathway?

Accepted Answer

Lactic acid fermentation; lactate

Question 11

Which of the following best explains why substrate saturation limits the rate of enzyme-catalyzed reactions?

Accepted Answer

All enzyme active sites are occupied, so increasing substrate concentration further does not increase the reaction rate

Question 12

Which of the following is an example of feedback inhibition in cellular respiration?

Accepted Answer

ATP binding to phosphofructokinase to decrease glycolysis

Question 13

Which of the following statements about photosynthesis and aerobic cellular respiration is correct?

Accepted Answer

Photosynthesis fixes carbon dioxide and releases oxygen, while cellular respiration consumes oxygen and releases carbon dioxide

Question 14

During the light-dependent reactions of photosynthesis, what is the primary role of chlorophyll?

Accepted Answer

To capture light energy and transfer excited electrons to the electron transport chain

Question 15

Rubisco is a critical enzyme in the Calvin cycle. What is a major consequence of its tendency to catalyze photorespiration?

Accepted Answer

Decreased efficiency of carbon fixation and loss of fixed carbon as CO$$_2$$

Question 16

Which of the following best distinguishes catabolic from anabolic pathways in metabolism?

Accepted Answer

Catabolic pathways break down molecules to release energy, while anabolic pathways build complex molecules from simpler ones

Question 17

A mutation causes a eukaryotic cell to lack functional lysosomes. Which process would be most directly affected?

Accepted Answer

Autophagy

Question 18

Which of the following is a key difference between the extracellular matrix (ECM) of animal and plant cells?

Accepted Answer

Animal ECM contains proteins like collagen and proteoglycans, while plant ECM contains cellulose and pectin

Question 19

Which of the following best describes the role of phosphorylation in cellular metabolism?

Accepted Answer

It can activate or deactivate enzymes and is used to couple exergonic and endergonic reactions

Question 20

A researcher adds a competitive inhibitor to an enzyme-catalyzed reaction. Which of the following best describes the effect of the inhibitor?

Accepted Answer

It binds to the active site, preventing substrate binding

General Biology: Cell Structure, Cell Communication, Metabolism, Respiration, and Photosynthesis

Guida di studio - Domande di pratica

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