Cell Structure AP Classroom

A model of the plasma membrane showing several biological molecules, including a transmembrane protein, is shown in Figure 1. (Figure 1. Phospholipid bilayer with transmembrane protein) Which statement best explains why correct protein folding is critical in the transmembrane protein shown above?

A: Interactions of the hydrophobic and hydrophilic amino acids help to anchor the protein in the membrane. Tertiary structure of the protein resulting from hydrophobic and hydrophilic interactions plays a key role in how the protein interacts with the hydrophobic tails and hydrophilic head of the membrane phospholipids.

Which of the following best supports the statement that mitochondria are descendants of endosymbiotic bacteria-like cells?

A: Mitochondria and bacteria possess similar ribosomes and DNA.

Synthesized at the ribosome

A: proteins

The following questions refer to the following diagram. For each phrase or sentence, select the labeled part to which it is most closely related. Site of modification and packaging of proteins and lipids prior to export from the cell

C: (C); Golgi Apparatus

a prokaryotic cell has which of the following?

C: plasma membrane

Which of the following groups of cellular components are found in eukaryotic cells but not prokaryotic cells?

D: An endoplasmic reticulum, mitochondria, and a nucleus

All eukaryotic cells contain at least one Golgi complex, typically located in the cytoplasm and near the endoplasmic reticulum. Which of the following best describes a process that occurs within the Golgi complex?

Enzymatic modification of newly synthesized integral membrane proteins The Golgi complex is a membrane-bound structure to which some proteins are moved from the rough endoplasmic reticulum, where they are enzymatically modified before being sent to a cellular membrane.

The figure above shows a series of microscope images taken over time of ovalbumin production in chick oviduct cells in response to stimulation with estrogen. The ovalbumin protein was detected using a fluorescent dye as shown by the white areas in the time-lapse sequence. The microscope images indicate that ovalbumin...

crosses the endoplasmic reticulum membrane as it is translated, then moves to the Golgi apparatus, then to vesicles from which it is secreted

all of the following cell components are found in prokaryotic cells EXCEPT

nuclear envelope

Organelles such as mitochondria and the endoplasmic reticulum have membranes that compartmentalize reactions and other metabolic processes. To function properly, the organelles must move substances across their membranes. Which of the following statements describes a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions?

they have highly folded membranes Compared with a smooth membrane, a highly folded membrane has a greater surface area that increases the rate of material transport across the membrane and provides more support for membrane-associated processes.

Which of the following best describes the numbered areas? (image: phospholipid bilayer; 1&3 are the heads)

Areas 1 and 3 are polar, since the membrane molecules are aligned with water molecules.

The following questions refer to the following diagram. For each phrase or sentence, select the labeled part to which it is most closely related. Evolved from a photoautotrophic prokaryote

B: (B); chloroplast

Mitochondria are found in most eukaryotic cells and contain their own DNA and ribosomes that are similar to those typical of many prokaryotic cells. Which of the following statements is justified by these observations?

B: An ancestral cell most likely engulfed anaerobic prokaryote in a relationship that proved beneficial for both cells.

Liver cells manufacture glycoproteins, while adipose cells store fat. Which of the following subcellular structures is likely to be more prominent in liver cells than in adipose cells?

B: Golgi Apparatus

Which of the following organelles modifies and packages for secretion the materials produced by the ribosomes?

B: Golgi apparatus

Which of the following conclusions is best supported by the data presented in Figure 1 (look at this question on my AP!)?

B: Implanted hESC-β cells are effective at regulating blood glucose levels in the absence of mouse β-cells.

Which of the following modifications to the experimental design would improve the reliability of the results presented in Figure 1 ?

B: Measuring blood glucose levels in a group of mice that were not given STZ

The model below shows the structure of a portion of a plasma membrane in an animal cell (image: phospholipid bilayer membrane) Which statement best explains the orientation of the phospholipid molecules in this model?

B: The hydrophilic phosphate groups of the phospholipid molecules are attracted to the aqueous internal and external environments. The hydrophilic polar phosphate groups of the phospholipid molecules orient toward the polar internal and external aqueous environments, forming a bilayer that keeps the hydrophobic portions of the phospholipids away from the polar molecules.

The figure shows a process by which a cell might absorb food from its surrounding environment and break it down for use as a source of energy and matter. The process involves lysosomes, which are membrane-bound organelles that contain hydrolytic enzymes. Activation of the hydrolytic enzymes requires an acidic pH, and lysosomes maintain an internal acidic pH by using ion pumps. Which of the following outcomes will most likely result from a loss of ion pump function in the cell's lysosomes?

B: The internal pH of the lysosomes will increase, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food.

The figure below illustrates a eukaryotic cell. Which of the following best describes how the three structures indicated by the arrows work together (rough ER, Golgi apparatus, vesicle)?

B: To synthesize and isolate proteins for secretion or for use in the cell

contains hydrolytic enzymes associated with the intracellular digestion of macromolecules

B: lysosome

Which of the following statements best predicts the effect of increasing the permeability of the mitochondrial membranes to large molecules?

C: ATP production will decrease because of an increase in the occurrence of uncontrolled chemical reactions. ATP production will most likely decrease. Increasing the permeability of the mitochondrial membranes to large molecules will likely result in a variety of uncontrolled substrate-enzyme interactions that will disrupt normal mitochondrial function.

Which of the following is true about the structure of the prokaryotic cell represented in the figure?

C: It has a cell wall exterior to the plasma membrane and contains ribosomes.

Membrane-bound organelles have been an important component in the evolution of complex, multicellular organisms. Which of the following best summarizes an advantage of eukaryotic cells having internal membranes?

C: Organelles isolate specific reactions, increasing metabolic efficiency. Demonstrates understanding and provides an explanation of how internal membrane-bound organelles contribute to cell function by providing a favorable local environment for metabolic reactions, and by protecting the cell from potentially damaging metabolic reactions.

Researchers claimed that a particular organelle originated from a free-living prokaryotic cell that was engulfed by a larger cell, as shown in Figure 1. (Figure 1. A model showing a cell engulfing a smaller cell.) Which of the following provides evidence to best support the researchers' claim?

C: The organelle has a double membrane The organelle's double membrane could have resulted from the process of endocytosis. Based on the claim, the organelle's inner membrane originated from the plasma membrane of the smaller cell and the organelle's outer membrane originated from the plasma membrane of the larger cell.

The diagram above represents a typical rod-shaped bacterium. Which of the following best describes a feature shown in the diagram that is unique to archaea and bacteria?

C: The organism does not have a nuclear membrane surrounding its genetic material.

Which of the following is a characteristic of mitochondria and chloroplasts that supports the endosymbiotic theory?

C: both contain DNA molecules

Prokaryotic and eukaryotic cells generally have which of the following features in common?

C: ribosomes

A pathogenic bacterium has been engulfed by a PHAGOCYTIC CELL as part of the nonspecific (innate) immune response. Which of the following illustrations best represents the response?

C: w/LYSOSOME

In the first step of an experiment, rat liver cells were exposed for 5 minutes to amino acids labeled with a radioactive isotope. The cells were then washed to stop any further incorporation of radioactive amino acids. The cells were sampled periodically thereafter, and the radioactivity of a certain protein (protein X) was measured in various cell components, as shown below (look at chart); what is the most likely identity of protein X?

D: An enzyme that participates in the degradation and recycling of cell components

Which of the following best describes an advantage that eukaryote organisms have over prokaryote organisms?

D: Eukaryotes have organelles that allow for compartmentalization of cellular processes, which increases the efficiency of those processes.

Which of the following statements best supports the claim that certain organelles within eukaryotic cells evolved from free-living prokaryotic cells?

D: Some organelles contain their own DNA that is more similar to prokaryotic DNA in structure and function than to the eukaryotic DNA found in the cell's nucleus.. The mitochondria and chloroplasts contain DNA more similar to prokaryote DNA in structure and function than to eukaryotic DNA. Eukaryotic DNA in the nucleus has additional structural proteins and a more complex process of protein synthesis. The most reasonable explanation involves the incorporation of one free-living prokaryotes that eventually integrated with the structures and processes of their eukaryotic hosts.

Individuals with an inherited autosomal recessive disorder called primary ciliary dyskinesia (PCD) often have severe respiratory problems due to defective cilia. Males with PCD are often sterile because they produce sperm with defective flagella. Which of the following most likely explains the effect of the recessive allele?

D: The cells do not produce functional motor proteins in flagella and cilia.

Which of the following are characteristic of both prokaryotic and eukaryotic cells?

E: Cell membrane, ribosomes, DNA, and RNA

Which of the following provides the weakest evidence that mitochondria were once free-living prokaryotes?

E: Mitochondria and prokaryotes both are found in a variety of sizes.

The endosymbiont theory proposes a model for the evolution of mitochondria. According to the model, an ancestral eukaryote engulfed a small, free-living prokaryotic organism. The engulfed prokaryote then formed an endosymbiotic relationship with the eukaryotic host. Which of the following observations best supports the model?

Mitochondria and some prokaryotes share similar metabolic reactions that produce ATP.

Changing the shape or morphology of the mitochondrial inner membrane can change the efficiency of mitochondrial function. Which of the following outcomes will most likely result from a change in the shape of the mitochondrial inner membrane from a highly folded surface to a smooth, flat surface?

Mitochondria will become less efficient because the surface area of the inner mitochondrial membranes will decrease. The change to the inner mitochondrial membrane will result in a decrease in the membrane's surface area, which will reduce the efficiency of mitochondrial function because there will be less surface area for reactions to occur.

Cells contain smaller components called organelles that are necessary for a cell's survival. Organelle functions have often been compared to components of larger systems. Which of the following functional differences between the rough and smooth endoplasmic reticulum (ER) is explained by the structural differences between them?

Rough ER can synthesize and package proteins for export, and smooth ER cannot. The ribosomes associated with rough ER synthesize proteins that are then exported from the cell.