SHort Answer AP Bio

considering the role of coenzyme Q, how do you think this product might function as a nutritional supplement to benefit the heart? IS CoQ used as a "fuel" during cellular respiration?

CoQ is not a fuel in the sense that it's consumed during cellular respiration, but it does help shuttle excited electrons between enzyme complexes during electron transport. this is where the fuel tha food is for our bodies is nearly done being converted into energy in the bonds in ATP, fuels are consumed in this process. as a nutritional supplement, CoQ can help provide enough material to keep cellular respiraton running at peak efficieny

For a short time in the 1930s, some physicians prescribed low doses of a compound called dinitrophenol (DNP) to help patients lose weight. This unsafe method was abandoned after some patients died. DNP uncouples the chemiosmotic machinery by making the inner mitochondrial membrane leaky to H+. Explain how this could cause weight loss and death.

because DNP makes the mitochondrial inner membrane leaky, its proton gradient will run down without producing ATP. this wastes the energy in food, so that weight will be lost. it's kinda like running in place without using muscles. if too much weight is lost or if not enough ATP is made due to the use of DNP, patients could die.

Explain how oxidative phosphorylation-- production of ATP using energy from the redox reactions of a spatially organized electron transport chain followed by chemiosmosis-- is an example of how new properties emerge at each level of the biological hierarchy.

emergent properties arise when more than one part works together and these are properties not obvious from the nature of the individual parts. the various individual parts of electron transport are not capable of making ATP, nor is the ATP synthase capable of doing this by itself. Nor is the membrane in which they are all placed capable of producing ATP alone. however when they work in the proper order , they can generate a proton protein which can be used to make ATP from the energy in that gradient.

The success of some viruses lies in their ability to evolve within the host. Such a virus evades the host's defenses by rapidly mutating and producing many altered progeny viruses before the body can mount an attack. Thus, the viruses present late in infection differ from those that initially infected the body. Discuss this as an example of evolution in microcosm. Which viral lineages tend to predominate?

evolution involves natural selection working on a diverse gene pool and picking better adapted genotypes/phenotypes. in this case, the gene pool is the different kinds of virus, and host defenses serve as the agent of natural selection. the most diverse lineages (least recognized by host defense) are the ones that survive. basically if you blend in, you stay alive.

considering this graph, under which condition is phosphofructokinase more active? Given what you know about glycolysis and regulation of metabolism by this enzyme, explain the mechanism by which phosphofructokinase activity differs depending on ATP concentration

examining the graph reveals that the curve with higher phosphofructokinase activity occurs when ATp concentrations are low

ATP synthases are found in the prokaryotic plasma membrane and in mitochondria and chloroplasts. what does this suggest about the evolutionary relationship of these eukaryotic organisms to prokaryotes? How might the amino acid sequences of the ATP synthases from the different sources support or refute your hypothesis?

mitochondria and chloroplasts probably originated as prokaryotic cells taken up by eukaryotic cells, which then converted the prokaryotes into organelles. if this is true, the ATP synthases in the prokaryotes and organelles should have similar sequences, showing the connection.

explain how this drug can prevent infection in someone exposed to the flu or could shorten the course of flu in an infected patient.

neuraminidase is an enzyme which is critical for the entry and release of viral particles into host cells so Tamiflu would either prevent any entry into host cells of an uninfected person or prevent new viral particles from lysed cells from infecting more cells in the same host. the first case prevents someone from having the flu. the 2nd case shortens the duration of infection by limiting reinfection.

Photorespiration can decrease soybeans' photosynthetic output by about 50%. Would you expect this figure to be higher or lower in wild relatives of soybeans? WHy?

one would expect the wild ancestors of cultivated soybeans would have been subjected to artificial selection to produce higher yields, which depend on greater photosynthetic efficiency, for a long time

describe how the process of photosynthesis in the chloroplasts of plants transforms the energy of sunlight into the chemical energy of sugat molecules.

photosynthesis absorbs the abundant energy of light , especially red and blue, and passes it through a large number of chemical steps to the carbons in newly made carbs. lots of energy is needed since fixing a co2 molecule from the atmosphere is very expensive, and the energy is carried in energy-dense ATP & NADPH molecules made during the light reactions. the calvin cycle does the actual carbon fixation, beginning with the enzyme rubisco

WOuld ATP end up in the thylakoid or outside of it? Explain why thylakoids in the experiment were able to make ATP in the dark.

the end product of ATP would end up outside b/c in a plant cell , it's used in the calvin cycle

based on what you learned in this chapter, propose an explanation for why this photosynthetic alga appears reddish-pink.

the pink/red color is probably due to a pigment in these cells which protect them from the UV radiation at high altitudes and latitudes

Explain the difference in the curves

the steps in B are due to the fact that the particles produced in a lytic cycle must reinfect the other cells to produce more particles. the flat step represents the time for reinfection and production of more particles

discuss how the structure of a virus correlates with its function

viral structure and function go together since viral proteins, like all proteins, do particular jobs based on their shape. there may be proteins, such a glycoproteins, which help the virus enter the host cells. other proteins are able to do jobs such as reverse transcription based on their shapes. the shape of the dna or rna bases in the viral genome determinethe info contained and what can be done with that inf just as in a living cell. in this way, viruses are like subsets of a living cell, which is one theory for their origins.

Scientific evidence indicates that the carbon dioxide added to the air by the burning of wood and fossil fuels is contributing to global warming, a rise in global temperature. Tropical rain forests are estimated to be responsible for approximately 20% of global photosynthesis, yet the consumption of large amounts of carbon dioxide by living trees is thought to make little or no net contribution to reduction of global warming. Why might this be?

while living trees do take up co2 from the atmosphere, they also give off some by doing cellular respiration and photorespiration . the greater production of co2 is from dead trees decomposing , which give off co2 as fungi and other microbes digest them and perform cellular respiration