Podcast
Questions and Answers
Which of the following results, one hour after membrane fusion, best supports the alternative hypothesis that the cell membrane is a fluid mosaic? (Select all that apply)
Which of the following results, one hour after membrane fusion, best supports the alternative hypothesis that the cell membrane is a fluid mosaic? (Select all that apply)
- The membrane of the cell has only grey proteins embedded in it.
- The membrane of the cell has only black proteins embedded in it.
- The membrane of the cell has both grey proteins and black proteins embedded in it. The grey proteins and black proteins are distributed throughout the cell membrane and are not concentrated in particular areas. (correct)
- The membrane of the cell has both grey proteins and black proteins embedded in it. The black proteins are concentrated in one area of the cell membrane, and the grey proteins are concentrated in a separate area of the cell membrane.
Which of the following data would best refute the alternative hypothesis that small nonpolar molecules require channel and transport proteins to move across the cell membrane? (Select all that apply)
Which of the following data would best refute the alternative hypothesis that small nonpolar molecules require channel and transport proteins to move across the cell membrane? (Select all that apply)
- Ethanol is found in the cytosol of cells when they are briefly exposed to a ten percent ethanol solution.
- Sodium ions cannot move across the cell membrane when membrane protein activity is blocked.
- CO2 and N2 movement in and out of cells is unaffected when membrane protein activity is blocked. (correct)
- Cells become oxygen deficient when membrane protein activity is blocked.
Which of the following functions is a certain type of specialized cell with an unusually large amount of rough endoplasmic reticulum most likely specialized to perform?
Which of the following functions is a certain type of specialized cell with an unusually large amount of rough endoplasmic reticulum most likely specialized to perform?
- The production and secretion of proteins (correct)
- The production and secretion of steroids
- The destruction of toxic materials produced in other cells of the organism
- The synthesis of polysaccharides for energy storage
Which of the following cellular deficiencies would most likely be related to the MT-ND1 mutations identified in mitochondrial DNA?
Which of the following cellular deficiencies would most likely be related to the MT-ND1 mutations identified in mitochondrial DNA?
Which cellular component will be found in the widest range of organisms in a marine ecosystem sample?
Which cellular component will be found in the widest range of organisms in a marine ecosystem sample?
What conclusion about the radiolabeled amino acid is best supported by the results of the experiment?
What conclusion about the radiolabeled amino acid is best supported by the results of the experiment?
Which claim about the effects of the valinomycin treatment on skeletal muscle cells is best supported by the data?
Which claim about the effects of the valinomycin treatment on skeletal muscle cells is best supported by the data?
What conclusion about increasing the number of folds in the inner mitochondrial membrane is best supported by the results of the experiment?
What conclusion about increasing the number of folds in the inner mitochondrial membrane is best supported by the results of the experiment?
Based on the provided data, which cell is likely to be most effective in the exchange of materials?
Based on the provided data, which cell is likely to be most effective in the exchange of materials?
What provides an accurate calculation of the surface area to volume ratio of an HS red blood cell and its effect on oxygen transferring efficiency?
What provides an accurate calculation of the surface area to volume ratio of an HS red blood cell and its effect on oxygen transferring efficiency?
How does the ratio of the density of stomata per CO2 concentration change as the CO2 concentration increases?
How does the ratio of the density of stomata per CO2 concentration change as the CO2 concentration increases?
Where does testosterone enter a cell and why is it able to cross at that point?
Where does testosterone enter a cell and why is it able to cross at that point?
Which statement best describes the relationship between regions 1 and 2 of the protein embedded in a cell membrane?
Which statement best describes the relationship between regions 1 and 2 of the protein embedded in a cell membrane?
How do cholesterol molecules most likely interact with the phospholipid bilayer of a cell's plasma membrane?
How do cholesterol molecules most likely interact with the phospholipid bilayer of a cell's plasma membrane?
What should a team of students do next to obtain more conclusive data about the effects of IV fluids with different salt concentrations on red blood cells?
What should a team of students do next to obtain more conclusive data about the effects of IV fluids with different salt concentrations on red blood cells?
What additional procedure would best help determine whether nutrient movements into bacterial cells are due to active or passive transport?
What additional procedure would best help determine whether nutrient movements into bacterial cells are due to active or passive transport?
Based on their observations, what should the researchers do to further clarify how the availability of the protein outside the cells affects the rate of endocytosis of the protein?
Based on their observations, what should the researchers do to further clarify how the availability of the protein outside the cells affects the rate of endocytosis of the protein?
Which of the following best predicts what will happen to the lysosomal enzymes if the proteins that transport H+ ions from the cytosol into the lysosome are damaged?
Which of the following best predicts what will happen to the lysosomal enzymes if the proteins that transport H+ ions from the cytosol into the lysosome are damaged?
Which of the following transport mechanisms will be affected most directly by a temporary shortage of ATP molecules inside the cell?
Which of the following transport mechanisms will be affected most directly by a temporary shortage of ATP molecules inside the cell?
Based on the model presented in Figure 1, which of the following changes will most likely result from a depletion of available ATP stores inside the cell?
Based on the model presented in Figure 1, which of the following changes will most likely result from a depletion of available ATP stores inside the cell?
Which of the following statements best explains why some substances can pass through an actual cell membrane much faster than they passed through an artificial membrane?
Which of the following statements best explains why some substances can pass through an actual cell membrane much faster than they passed through an artificial membrane?
By which of the following mechanisms do water molecules most likely move into the large intestine after taking magnesium sulfate orally?
By which of the following mechanisms do water molecules most likely move into the large intestine after taking magnesium sulfate orally?
How does aldosterone most likely enter target cells?
How does aldosterone most likely enter target cells?
Which of the graphs below best represents the predicted change in mass over time of the dialysis bag in the beaker to which albumin was added?
Which of the graphs below best represents the predicted change in mass over time of the dialysis bag in the beaker to which albumin was added?
Which prediction of the effect of lysosome membrane rupture is most likely correct?
Which prediction of the effect of lysosome membrane rupture is most likely correct?
Gaucher disease results most directly from a defect in the function of which of the following organelles?
Gaucher disease results most directly from a defect in the function of which of the following organelles?
Which of the following observations best supports the model that chloroplasts evolved from a small prokaryotic organism engulfed by an ancestral eukaryote?
Which of the following observations best supports the model that chloroplasts evolved from a small prokaryotic organism engulfed by an ancestral eukaryote?
Which observation best supports the claim that mitochondria evolved from once-free-living prokaryotic cells by the process of endocytosis?
Which observation best supports the claim that mitochondria evolved from once-free-living prokaryotic cells by the process of endocytosis?
Which of the following claims about the origin of the euglenid chloroplast is best supported by the three-membrane structure of the envelope?
Which of the following claims about the origin of the euglenid chloroplast is best supported by the three-membrane structure of the envelope?
Which result best refutes the alternative hypothesis that selective permeability of beetroot cells is a consequence of the cell wall?
Which result best refutes the alternative hypothesis that selective permeability of beetroot cells is a consequence of the cell wall?
The hypothesis states that membrane structure is static and membrane components throughout the bilayer are rigidly bound.
The hypothesis states that membrane structure is static and membrane components throughout the bilayer are rigidly bound.
Study Notes
Specialized Cells and Rough ER
- Cells with high rough ER content are specialized for protein production and secretion.
- Rough ER is linked with ribosomes, which synthesize proteins transported to the Golgi complex and then out of the cell.
Mitochondrial Mutations and Cellular Functions
- MT-ND1 mutations in mitochondrial DNA lead to nonfunctional proteins and diseases.
- Cells with these mutations struggle with electron transport and ATP production.
Common Cellular Components
- Ribosomes are ubiquitous across both prokaryotic and eukaryotic organisms since they are essential for protein synthesis.
Radiolabeled Amino Acid Experiment
- The highest amount of a radiolabeled amino acid was found in mitochondria, indicating its incorporation into proteins regulating metabolic reactions.
Valinomycin Effects on ATP Production
- Valinomycin treatment resulted in decreased ATP production rates in skeletal muscle cells, indicating impaired mitochondrial function.
Mitochondrial Membrane Efficiency
- More folds in the mitochondrial membrane increase ATP production efficiency by providing greater surface area for ATP synthase, enhancing cell growth.
Surface Area to Volume Ratio in Cells
- Among four eukaryotic cells, the one with a 6:1 surface area to volume ratio is likely the most efficient in material exchange.
Hereditary Spherocytosis (HS) and Oxygen Transfer
- HS red blood cells have a surface area to volume ratio of 0.89, making them less efficient at oxygen transfer compared to normal cells with a ratio of 1.49.
Stomata Density and CO2 Concentration
- Stomata density decreases as CO2 concentration increases, indicating fewer stomata are necessary at higher CO2 levels.
Steroid Hormone Movement Across Membrane
- Testosterone, being a nonpolar steroid, can easily diffuse through the cell membrane's lipid bilayer.
Hydrophilic and Hydrophobic Protein Regions
- A membrane protein's exterior is hydrophilic while the part interacting with fatty acid tails is hydrophobic, aligning with the properties of the phospholipid bilayer.
Cholesterol in Cell Membranes
- Cholesterol molecules interact with phospholipid bilayers by placing polar heads between phospholipid heads, while nonpolar regions embed within the bilayer.
IV Therapy and Red Blood Cell Research
- IV therapy involves studying the effects of different salt concentrations on red blood cells, with findings indicating that research should extend to other concentrations for conclusive data.
Transport Mechanisms in Bacteria
- The transport rate of ethyl alcohol and acetate into bacteria should be compared with ATP-blocking treatments to determine if the transport is active or passive.
Endocytosis and Protein Availability
- To study how protein availability affects endocytosis rates, researchers should experiment with varying concentrations of the protein.
Lysosomes and pH Regulation
- Damaging H+ transport proteins in lysosomes will prevent activation of lysosomal enzymes since their activity depends on a lower pH achieved through active transport of H+ ions.### Transport Mechanisms and ATP Dependence
- Active transport is essential for moving molecules against concentration gradients, requiring ATP energy input.
- A shortage of ATP directly impacts the transport of glucose molecules, leading to increased intracellular Na+ concentrations as pumps fail to function.
Membrane Proteins and Ion Concentration
- Membrane proteins regulate ion concentrations, including Na+ and K+ across plasma membranes.
- In the presence of ATP depletion, Na+ ions continue to leak into the cell, leading to increasing concentrations inside the cell.
Cell Membrane Structure and Function
- Actual cell membranes feature embedded proteins, enhancing substance movement compared to artificial membranes.
- These proteins facilitate both active and passive transport across the membrane.
Water Movement through Aquaporins
- Water diffuses into the large intestine from an area of low osmolarity to high osmolarity via aquaporins, demonstrating passive transport processes.
Aldosterone and Membrane Permeability
- Aldosterone, a small hydrophobic molecule, enters cells through simple diffusion, aligning with its nonpolar characteristics.
Dialysis and Osmotic Changes
- The introduction of a concentrated solution of albumin alters the osmotic environment, leading to mass changes in dialysis bags.
Lysosome Rupture Effects
- Disruption of lysosomal membranes releases hydrolytic enzymes, potentially leading to cell death; this mechanism halts viral replication.
Gaucher Disease and Lysosomal Function
- Gaucher disease results from defective lysosomal function, preventing lipid breakdown and causing toxic accumulation.
Evolutionary Models of Chloroplasts and Mitochondria
- Chloroplasts likely evolved through endosymbiotic events with prokaryotes, evidenced by similar photosynthetic mechanisms.
- The double membrane structure of mitochondria supports their evolution from a free-living aerobic bacterium.
Euglenid Chloroplast Structure
- The three-membrane structure of euglenid chloroplasts supports two endosymbiotic events, reflecting a complex evolutionary history.
Selective Permeability of Beetroot Cells
- The impermeability of betalains in beetroot cells, even after cell wall damage, indicates selective permeability is due to the cell membrane.
Fluid Mosaic Model of Cell Membranes
- Membrane fusion experiments revealing mixed protein distribution within the bilayer support the fluid mosaic model of cell membrane structure.
Molecule Movement and Membrane Permeability
- Data showing CO2 and N2 passage into cells without membrane proteins refute the necessity of channel proteins for small nonpolar molecule transport, confirming their ability to diffuse freely.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on specialized cells and their functions from AP Biology Chapter 2. This quiz focuses on the role of rough endoplasmic reticulum in various cell types. Perfect for preparing for the AP exam!
