ap bio 2-3 frq

1a). Identify the rectangular solid that represents the cell with the smallest amount of plasma membrane per volume of cytoplasm.

Rectangular solid 1 has the smallest surface area-to-volume ratio.

1b). Describe the relationship between the dimensions of the rectangular solids and their surface-to-volume ratios

The more surface area the rectangular solid has, the higher their surface area-to-volume ratio will be, which means the cell will be more efficient.

1c). Using the data from the model, evaluate the hypothesis that cells shaped like rectangular solids 1 and 2 are better suited for slow metabolism and the long-term storage of energy-containing molecules than are cells shaped like rectangular solids 4 and 5.

Cells with a lower surface area-to-volume ratio means that the cell is most likely bigger and it will take more time for molecules to get in and out of the cell and perform their function, like cells 1 and 2. Cells like 4 and 5, have a higher SA:V ratio which means that the cell is able to carry out faster metabolic reactions.

1d). Based on the trends shown in the data, explain why some rectangular cells include folds or projections in their plasma membranes.

The reason that cells have folds and/or projections in their plasma membranes is to help them obtain more surface area to make their rates of metabolic activities greater.

2a). Describe the energy-releasing reaction shown in Figure 1

The energy process that is being released is called phosphorylation. ATP is giving one of its phosphate groups to FBP from F6P to change ATP to ADP with the aid of PFK.

2b). Identify an independent variable in the experiment shown in Figure 3. Justify using a temperature range of 5 C to 25 C when the scientists performed the experiments described. Based on Figure 2, describe the effect of adding AMP to the reactions carried out at 25 C. Based on Figure 2, calculate the fold increase in the reaction rate (how many times greater the reaction rate is) at 25 C in the presence of 0.5 mM AMP when the concentration of F6P increases from 0.2 mM to 0.9 mM.

An independent variable in figure 3 would be the concentration of citric acid and temperature. They used that range of temperature because they got 3 different results for each temperature. Adding AMP at 25 C causes a higher rate of reaction at lower concentration and eventually reach a plateau. You reach a higher rate of reaction with AMP. The estimate fold of the reaction rate is 1.75.

2c). State the null hypothesis for the experiments shown in Figure 2. Based on the maximum and 50% of maximum reaction rates in the data shown in figure 3, the scientists claim that PFK of red king crabs is more sensitive to the presence of citric acid at 5 C than it is at higher temperatures. Support the scientists' claim based on the data provided. Predict the effect on the interaction of PFK and F6P and ATP if PFK is preincubated in a solution with a salt concentration much higher than that of seawater for 20 minutes prior to starting the reaction.

There is no statistical evidence that the addition of 0.5 AMP at 2 different temperatures will have an effect on the rate of PFK reaction. When it is at 5 C, the amount of concentration that is needed to slow the reaction down is less than what you would need to slow the reaction down at a warmer temperature like 30 C. I predict that if you put PFK in a higher concentration of salt than it is used to, it will denature the enzyme.

2d). Explain how an increase in northern Pacific Ocean temperatures up to 20 C will most likely affect the maximum metabolic rate of red king crabs, based on the data provided above. When isolated cells of red king crabs are transferred from an isotonic growth medium to a hypotonic growth medium, the cells swell. When the cells are returned to the isotonic medium, the cells shrink. Explain why the cells increase AND decrease in size.

The higher the temperature it is, the peak rate of reaction will be higher. If the isotonic cell is placed in a hypotonic medium, the cell will swell because the molar concentration of the cell is higher than the hypotonic medium, which causes the net flow to go into the cell. Now the cell is hypotonic to the isotonic medium it was in before, causing the net flow to go out of the cell when placed back into the isotonic solution.

3a). Describe the effect on chlorophyll-containing photosystems when the chlorophyll molecules absorb photons of light

When a photon of light hits the chlorophyll, the electron becomes excited and it travels through the electron transport chain.

3b). Identify an appropriate control that the researchers should use when they study the growth and photosynthetic ability of the plant with the mutant enzyme.

An appropriate control that they could use would be a plant that does not have a mutant form of the enzyme.

3c). Scientists claim that a plant that has more than one type of photosynthetic pigment has greater fitness than a plant that has only one type of photosynthetic pigment. Provide reasoning to justify this claim.

If a plant has more than one type of photosynthetic pigment, the plant will be able to absorb more light than a plant with just one type. This will allow for the electrons to excite more often and have double the amount of opportunity to grow and create energy.

4). Using the information above, describe ONE contribution of each of the following in ATP synthesis.
-Catabolism of glucose in glycolysis and pyruvate oxidation
-Oxidation of intermediates in the Krebs cycle
-Formation of a proton gradient by the electron transport chain

-The glucose breaks down into carbon chains to create pyruvic acid.
-Oxidation releases NADH, which is a hydrogen carrier molecule.
-The hydrogens are pumped through ATP synthase which allows for ADP+P to convert to 32-34 ATP.

5b). Respiration is a series of enzyme-catalyzed reactions. Using your knowledge of enzymes and the data above, analyze and explain the results of this experiment.

Temperature is a factor that can affect an enzyme. this experiment proves that to us because it shows that a yeast is the most effective at 30 C because the number of bubbles of gas produced per minute was the greatest at that time. Enzymes like to have things perfect for them and they will only perform their best when conditions are just right for them.

5c). Design an experiment to test the effect of varying the pH of the sugar solution on the rate of respiration. Include a prediction of the expected results.

I would place the yeast with the sugar solution, surrounded pH of 1-10. This will show me at which pH the rate of respiration in yeast cells will be optimal. My prediction is that they will have the greatest rate of respiration at a pH of 7 because that is a neutral state.

6b). Identify and explain the control or controls for this experiment

The control for this experiment is the light, unboiled % transmittance (sample 1). This is the control because it was the the only tube that didn't have any factors altered.

6c). The differences in the curves of the graphed data indicate that there were differences in the number of electrons produced in the 3 samples during the experiment. Discuss how electrons are generated in photosynthesis and why 3 samples gave different transmittance results.

Electrons are generated in photosynthesis when the sunlight hits the chloroplasts. Water molecules are split at the first electron transport chain which excites the electrons. The 3 samples gave different results because chlorophyll and light were restricted during the experiments which altered the rate of photosynthesis.