AP Bio Chapter 6 and 7 FRQ's
D) Describe the most likely effect of gasdermin pore formation on water balance in the cell in a hypotonic environment.
In a hypotonic environment, gasdermin pore formation would allow water to move into the cell in a net amount. This is because the cell would have a higher solute concentration compared to the surrounding environment. Better known as osmosis, the diffusion of water involves moving towards higher solute concentration.
a) In the provided model of a cell, draw arrows to describe the pathway for production of a normal CFTR protein from gene expression to final cellular location. (b) Identify the most likely cellular location of the ribosomes that synthesize CFTR protein. (c) Identify the most likely cellular location of a mutant CFTR protein that has an amino acid substitution in the ATP-binding site.
a) In the provided model of a cell, draw arrows to describe the pathway for production of a normal CFTR protein from gene expression to final cellular location. Nucleus/nuclear envelope - endoplasmic reticulum - Golgi apparatus - plasma membrane b) The most likely cellular location is the rough ER. c) The most likely cellular location is the plasma membrane.
(a) Using the experimental results, describe the pathway that secretory proteins take from their synthesis to their release from the cell. (b) Predict what the results would be if mRNA were radioactively labeled instead of polypeptides. Give reasoning to support your prediction.
a) Proteins start in the nucleus, travel down to the rough ER, and later travel through the Golgi apparatus. The proteins are later secreted from the cell through exocytosis at the 30 minute marker. b) The mRNA is produced and transported to the cytosol where it interacts with a free cytosolic ribosome. From there SRP (signal receptor protein) transports the mRNA to the ER. This is because mRNA is very specific in its track.
Describe the most likely effect of LAP94 activity on the osmolarity of the cytosol. Describe the function of LAP94 in maintaining water balance in the mussels living in the Atlantic Ocean.
Lap 94 most likely increases the similarity of cytosol. The allele also increases solute concentration of cytosine in the surrounding environment which is beneficial to mussels as they don't lose as much water from their cells through diffusion.
Endosymbiosis has been proposed as a model for the evolution of eukaryotic cell structure. Identify and explain TWO pieces of evidence that support the endosymbiotic theory.
Mitochondria and chloroplasts grow and reproduce as semiautonomous organelles. This means that both have their own plasma membrane with a phospholipid bilayer and split like a prokaryotic cell would. Both organelles also have their own circular DNA. This DNA directs the synthesis of some of the organelle's proteins, which are made on the ribosomes inside the organelles. This further splits apart the chloroplasts and mitochondria because other organelles do not have their own DNA.
Based on Figure 1, describe the direct source of energy used to move glucose into the epithelial cell from the intestinal lumen. Explain how this system maximizes glucose absorption from the intestinal lumen into the epithelial cells and from the epithelial cells into the blood.
The direct source of energy is energy from the sodium gradient. This energy is most likely ATP made in the mitochondria of the cell, as it is used in the sodium-potassium pump. During the absorption of glucose in the small intestinal lumen, the following processes occur. Sodium ions inside the small intestinal cells are moved into the interstitial fluid and into the blood by the sodium-potassium pump. The resulting low sodium in the intracellular environment creates a concentration gradient that triggers the transportation of sodium ions from the intestinal lumen into the small intestinal cells or enterocytes, by a mechanism called facilitated diffusion. Facilitated diffusion means diffusion facilitated by a transport protein. This transport protein, called the the sodium-glucose cotransporter, transports sodium alongside glucose into the cells. After glucose has been transported into the cell, it is then moved through the basal and lateral membranes into the blood by another transport protein called GLUT2.
Describe the structure and function of TWO eukaryotic membrane-bound organelles other than the nucleus.
The golgi apparatus is a series of flattened sacs that modifies, packs, and processes molecules sent from the ER. It receives newly made things from the ER through its cis face through transport vesciles and releases newly modified vesicles to be sorted out and sent through its trans face. These vesicles (sacs) and their contents can be targeted for various locations in the cell and to its exterior. Lysosomes are vesicles with hydrolytic enzymes. They aid in the digestion or breakdown of molecules, waste materials, and food with digestive enzymes. This can help cause cell lysis, which is cell burst and can help in recycling organelles
(a) Identify the cellular component in the model that is responsible for the increase in the pH of the vacuole during flower opening AND describe the component's role in changing the pH of the vacuole. (b) A researcher claims that the activation of the K+/H+ transport protein causes the vacuole to swell with water. Provide reasoning to support the researcher's claim.
a) The ( K+/H+) transport protein is identified as the cellular component responsible for the increase in pH, the component's role is described as moving H+ out of the vacuole b) The concentration of solute K is increasing inside the vacuole. It is moving into the vacuole, making it hypertonic, lowering water potential.
(a) Identify FOUR organelles that should be present in the eukaryotic organism and describe the function of each organelle. (b) Prokaryotic cells lack membrane-bound organelles found in eukaryotes. However, prokaryotes must perform many of the same functions as eukaryotes. For THREE of the organelles identified in part (a), explain how prokaryotic cells carry out the associated functions. (c) According to the endosymbiotic theory, some organelles are believed to have evolved through a symbiotic relationship between eukaryotic and prokaryotic cells. Describe THREE observations that support the endosymbiotic theory.
a)Ribosomes are the site of protein synthesis. The ER (endoplasmic reticulum) deals with internal transport or compartmentalization. The Mitochondria synthesizes ATP and undergoes aerobic/cellular respiration. Lysosomes deal with the enzymatic hydrolysis of wastes/metabolites/pathogens. Chloroplasts deal in light absorption and photosynthesis. b. Ribosomoes are still the site of protein synthesis. The mitochondria is not present in prokaryotes so other membranes or cytosolic molecules have to make ATP. The ER (endoplasmic reticulum) does the diffusion of molecules in the cytosol of prokaryotic cells. c. Mitochondria contain their own DNA. Chloroplasts contain their own DNA. Mitochondria can self-replicate.
(a) Describe how the phospholipids of a plasma membrane regulate the movement of large or polar molecules across the membrane. Explain how osmosis will affect animal cells when the cells are placed into an environment with a low water potential (high solute concentration) compared to the intracellular water potential. (c) Describe how increasing salinity affects the amount of fluid ejected each time a contractile vacuole contracts. Calculate the water potential (Ψ) of an animal cell without contractile vacuoles if water enters the cell and creates a solute potential (ΨS) of −2. Assume that the pressure potential (ΨP) in the cell is 0.
a. The plasma membrane is selectively permeable. Integral membrane proteins enable ions and large polar molecules to pass through the membrane in active or passive transport. When an animal cell is placed into an environment with low water potential, the net diffusion of the water will go from high water potential to low water potential, meaning water will flow outside the cell into the outside environment. c. Increased salinity will affect the amount of fluid ejected each time a contractile vacuole contracts because the surrounding water becomes more hypertonic as salinity increases. Since the tonicity increases, water potential decreases, and more water will be ejected from the vacuole because, in osmosis, water moves from high water concentration to low water concentration. math: -2
(a) Identify the individual who most likely exhibits symptoms of cystinuria. (b) Describe the relationship between the total number of mutant alleles in an individual and the concentration of cysteine in the urine. (c) Evaluate the hypothesis that mutations in SLC7A9 have a greater effect on the transport of cysteine across the plasma membrane of kidney cells than do mutations in SLC3A1 (d) Explain how the data support the claim that cysteine is a large polar molecule.
a. invididual 1 b. The higher the number of mutant alleles, the greater the concentration of cysteine in urine relative to normal values. c. The hypothesis may be correct. If the number of mutant alleles in SLC7A9 is higher than the number of mutant alleles in SLC3A1, then the concentration of cysteine in urine is lower. This means that the transportation of cysteine is affected to a greater extent if a mutant allele is present in SLC7A9. d. The concentration of cysteine is affected by the mutant allele which is a complex protein. If a complex protein is low, cysteine is not transported back, thus making its urine concentration higher.
(a) Using the most appropriate data, construct a labeled graph on the axes provided below to best illustrate water movement into and out of the egg. Explain why there is a difference in percent of mass change of the eggs in the different sucrose solutions. (b) Using the data, determine the molar concentration of chicken egg cytoplasm and justify your answer. (c) Movement of water and nutrients is critical for the survival of plants. Using the concept of water potential, explain the role of positive and negative pressure in the transport of water and nutrients throughout a vascular plant.
a.) graph needs to be labeled x-axis of molar concentration and y-axis of change in mass, correctly scaled, have correct points. The egg gains mass if the solute concentration is lower outside of the egg (hypotonic) causing water to move into the egg. The egg loses mass if its solute concentration is higher outside of the egg (hypertonic), causing water to move out of the egg. Water moves from low solute/high water concentration to high solute/low water concentration. b.) Correct molar concentration based on graph -0.32M (0.3M to 0.5M), Explanation: When y = 0, there is no change in mass = no net water movement = isotonic = solute concentration inside egg and outside egg are the same c) idk let's hope we do not get this question
