Human fragile sites are associated with _____.

To achieve proper cell and tissue growth, a tissue-engineered product must accommodate blood flow similar to that of the native tissue. Without blood flow to deliver oxygen, glucose, and other essential nutrients while removing waste materials, the size of the implant is limited. A company develops a porous bone graft which permits glucose to flow into the interior. A 50 g/min buffer solution containing 5 mg/mL of glucose flows into the bone graft.

Solve in MatLab and MathCAD

(a) What is the expected total mass flow rate and mass flow rate of glucose out of the system?

(b) Determine the total mass of glucose to flow through the bone graft in a 24 hour period.

(c) Laboratory results show the total outlet mass flow rate is 50 g/min. The outlet glucose mass flow rate is 225 mg/min. Make conjectures about what has happened in this experiment.

Acetylcholinesterase catalyzes the hydrolysis of the neurotransmitter acetylcholine: Acetylcholine + H2O  acetate + choline The Km of acetylcholinesterase for its substrate acetylcholine is 9.5x10-5M. In a reaction mixture containing 5 nanomoles/mL of acetylcholinesterase and 150μM acetylcholine, a velocity vo=40μmol/mLsec was observed for the acetylcholinesterase reaction.

a. Calculate Vmax for this amount of enzyme

b. Calculate kcat for acetylcholinesterase

c. Calculate the catalytic efficiency (kcat/Km) for acetylcholinesterase

d. Does acetylcholinesterase approach catalytic perfection?

e. What determines the ultimate speed limit of an enzyme-catalyzed reaction? That is, what is it that imposes the physical limit on catalytic perfection?

1. Examine the DNA sequence shown below. How many possible reading frames does this piece of DNA have? Explain where they are. Which one can be used and how do you know?

5'-AGTCGA TCGAACGGTCA TCG-3' 3'-TCAGCTAGCTTGCCAGTAGC-5'

2. What feature of eukaryotes makes annotation more difficult?

3. Describe the process whereby DNA is transferred from Agrobacterium to plants.

It can be argued that almost all diseases have, at their root, a cellular basis. This means we can typically trace every genetic or acquired condition to a problem in a specific type of cell. Is it possible, however, that these diseases/conditions/traits can actually be traced as far as the organelle level? Explore this possibility.

Considerable effort has been directed toward determining the genes in which sequence variation contributes to the development of type 2 diabetes, a disease that results from a loss of sensitivity of cells to insulin. Approximately 800 genes have been implicated. Explain the significance of the observation.

DCMU is marketed as an algicide and an herbicide. It works by blocking the binding site for plastoquinone on photosystem II.

1. If DCMU blocks plastoquinone from binding to photosystem II then in what state (oxidized or reduced) will the chlorophyll a of photosystem II be stuck? Why?
2. Based on your answer above, in what state would plastoquinone be stuck? Why?
3. Considering where DCMU binds, would plants in nature exposed to DCMU be able to produce

ATP and NADPH through the light reactions? Why or why not?

4. If plants exposed to DCMU cannot produce ATP and NADPH through the light reactions, how

would this affect the light-independent reactions?

5. DCMU, as an herbicide, will eventually kill plants that are exposed to it. Why is this the case? In

answering this, relate DCMU to photosynthesis and both DCMU and photosynthesis to cellular respiration.

2. The hydrolysis of ATP is the cell’s most commonly used exergonic reaction when performing energy coupling. Explain energy coupling, why it is necessary, and how the hydrolysis of ATP fits into the process. Use vocabulary words such as “endergonic,” “exergonic,” “spontaneous,” and “nonspontaneous.” (8 points)

4. Prokaryotic organisms do not have membrane-bound organelles. However, they are able to make ATP and survive.

   1. Assuming that bacteria cannot use their membranes to make ATP, which process can they still use in order to generate ATP? (2 points)

   2. Why can they perform this process even though they lack membrane-bound organelles?

      (2 points)

. 1. Explain Hamilton’s Rule in words.

2. Relate indirect fitness and kin selection to the alarm callings of black tailed prairie dogs.

4. Does kin selection explain how humans distribute wealth? (You don’t have to write about this, but what about something like the Bill and Melinda Gates Foundation? Think about how you’d explain that.)

Energetics and Metabolism Activity

Humans are described in a couple of different ways in relation to maintaining body temperature: homeotherm and endotherm are two common phrases. “Homeotherm” translates to “same temperature,” meaning humans maintain a stable body temperature regardless of the external environment. Related is the term “endotherm,” meaning “internal body temperature.” Humans, being warm-blooded, are dependent and capable of internally generating heat when needed. Regardless of the phrase used, the ability to maintain a stable body temperature is a critical part of our homeostasis. Therefore, we expend a lot of energy to maintain a near-constant internal environment of 37°C, which is largely accomplished by our metabolism.

Other organisms are poikilotherms or ectotherms; they cannot internally regulate their body temperature, and their body temperature can change depending on the external environment. Most fish, sharks, reptiles and amphibians fall into this category. While ectothermy is a significant energy-saving adaptation, it also means an organism’s metabolic rate is dependent upon the external environment. Higher temperatures increase metabolic rate, colder temperatures slow it down.  

In this activity, you will be examining the effects increased temperature has on the metabolic rates of three species of fish.

Go to the following website, and perform the experiment:

http://www.glencoe.com/sites/common_assets/science/virtual_labs/CT08/CT08.html

Fill in the table below with your results:

1. Interpret your results from the experiment; what do these data tell you about fish metabolic rate in response to temperature?

2. How might ectotherms have to compensate for their variability in metabolic rate in terms of how much they eat?

3. Compare and contrast the basal metabolic rate of a fish and a human. How are each maintained? How might the BMR of each change in a warm environment? A cold environment?

The plasma membrane is a structure common to all cell types and important in providing the cell with selective permeability. Identify one way that certain organisms can change the construction of their plasma membrane given changing environmental conditions (beside  biochemistry)

Linda has asked Brenn to prepare a 1% agarose gel for a gel electrophoresis analysis. But before he could do that, he needs to prepare 600 ml of 1x TAE from 95x TAE. How much 95x TAE and water should he add to create the 1x TAE solution? Afterwards, how much agarose does he need to weigh out, in grams, and add into 50 ml of 1x TAE?

Imagine a student measures the concentration of a bacterial culture using the "direct microscopic method" (using a hemocytometer) and by "using turbidity to count cells in liquid culture." Based on their calculations, there were 10,000 total cells/mL and the viability of the culture was 90%. Which method allowed the student to determine viability and why/how?

What is the role of news media in a democracy? How is quality journalism compromised by media conglomeration?