1.) Vibrio cholerae is a Gram-negative, curved-shaped bacterial pathogen which causes nausea, vomiting, diarrhea and muscle cramps after consuming fecal contaminated water. Cholera killed thousands of people during the 1800’s as people traveled West to colonize the United States and more recently in Haiti after a devastating earthquake in 2010. Vibrio’s ability to cause potentially deadly diarrhea is due to a toxin it secretes called Cholera Toxin (CT). Vibrio is thought to have gained the gene which codes for CT from a bacteriophage.

A.) Which form of horizontal gene transfer (conjugation, transduction OR transformation) allowed Vibrio to produce the cholera toxin? (1p)

B.) Briefly describe the steps involved during this particular form of horizontal gene transfer. (2pts)

C.) Research and briefly explain how the rapid dipstick test works for identification of V. cholerae. Is it biochemical, immunological or genetic identification? (2pts)

2. Here is the figure of the G protein couple receptor (GPCR) activation of K+ channels in the pacemaker cells of the heart (right).

Under which of the following scenarios would the effect of acetylcholine be enhanced (thus resulting in slowing the heart beat rate)? For those scenarios which do not enhance the effect of acetylcholine, explain why it would not do so. (3 pts)

a. Changes in the protein structure of the K⁺ channel which would decrease the interaction of the activated bg complex and the K⁺ channel.

b. An extremely high affinity of the G protein for GDP.

c. GTP molecules which are not hydrolysable

d. Changes in the receptor protein which decreases the affinity of the receptor for acetylcholine

3. Compare and contrast cell signaling via GTP-binding proteins (molecular switches) and signaling through the cortisol activation of a transcription factor (4 pts).

4. Many extracelluar signals which promote survival and growth work through RTKs. The activated AKt (also called protein kinase B) promotes cells survival through its interaction with Bad and Bcl2. Akt is able to phosphorylate Bad which inactivates it (thus it no longer will promote cell suicide).

Which of the following scenarios are false? If they are false explain why they are false.

a. When Akt is activated, its major function is to phosphorylate other proteins

b. When there are signals for cell death, Akt will be phosphorylated:

c. When Akt is activated, it will inhibit Bcl2:

d. Akt is activated when it is phosphorylated.

Describe the mechanism in bacteria for repair of DNA containing mismatches, chemically modified bases, and double strand breaks.

Please CITE. Thank you.

PLEASE TYPE YOUR ANSWER

Imagin you are a student who took microbiology in a semester. how you explain that

What did you learn from your microbiology experiences in this semester that will continue to influence you for many years to come? How did you learn these things?

Using specific examples for your statement Such as PPE, Gram stain, HMB, sensitive to penicillin, etc.

1. Describe how the unique reactions of GNG represent a pathway distinct from glycolysis based on the free change of the reaction catalyzed by the glycolysis enzyme, phosphofructokinase
2. Describe the functions of phosphoglucomutase and glucose 6-phosphatase enzymes in the pathway connecting glycogen breakdown to glucose export in liver cells.

3. Gluconeogenesis (GNG)

   Review coupled reactions (McKee page 120-121). It is useful and customary to express the number of GTP, UTP, or other nucleotides consumed or produced in a pathway as equivalent to ATP. A cellular reaction that exchanges the terminal phosphate between ADP and another nucleoside diphosphate is catalyzed by nucleoside diphosphate kinase (McKee page 347) One of the reactions of GNG consumes GTP. The task is to find the overall reaction that gives the equivalent change in ATP.

PLEASE TYPE YOUR ANSWER

Imagin you are a student who took microbiology in a semester. how you explain that What did you learn from your microbiology experiences in this semester that will continue to influence you for many years to come? How did you learn these things?

Using specific examples for your statement Such as PPE, Gram stain, HMB, sensitive to penicillin, etc.

What functional groups are associated with carbohydrates, lipids, proteins, and nucleic acids

What are the functions of carbohydrates?  Give examples of monosaccharides, disaccharides, and polysaccharides.

What are the characteristics of lipids?

How are saturated fats different from unsaturated fats?

Explain how super-antigens, such as toxic shock syndrome toxin produced by Staphylococcus aureus, often lead to the development of life-threatening symptoms in an infected individual.

9) The site of the bacterial cell where ATP is produced is the:

a)   plasma membrane

b)   cell wall

c)   flagella

d)   nuclear region

e)   cytoplasm

44) Which of the following is regulated by an operator:

a) DNA sythesis

b) protein synthesis

c) RNA synthesis

d) b and c

e) all of the above

44) Which of the following is regulated by an operator:

a) DNA sythesis

b) protein synthesis

c) RNA synthesis

d) b and c

e) all of the above

56) Single amino acids are found on:

a) DNA

b) mRNA

c) tRNA

d) rRNA

e) Proteins

77) If a solution of 1x107 bacteria/milliliter were diluted one million times and then one tenth of a milliliter of that dilution was added to a Petri dish, how many bacterial colonies would you find after incubation for one or two days:

a) 1

b) 10

c) 100

d) 1,000

e) 10,000

78) If a solution of 1x105 bacteria/milliliter were diluted ten thousand times and then one tenth of a milliliter of that dilution was added to a Petri dish, how many bacterial colonies would you find after incubation for one or two days:

a) 1

b) 10

c) 100

d) 1,000

e) 10,000

A person takes a Ca-Mg-Zn pill daily. Zn can inhibit the absorption of Mg. An intake of >142mg of Zn will prevent Mg absorption. However, an intake of >500 mg of Ca can rescue Mg absorption that is blocked by Zn. One dose of the supplement contains 1.502 x 10²² atoms of Ca, 9.94 x 10²¹ atoms of Mg, and 1.379 x 10²⁰ atoms of Zn. With this information, answer the following:

A) How many doses of the pill is necessary to reach the Zn threshold which blocks Mg absorption?

B) The calcium in this pill is in the form of calcium carbonate, and only 15% of the calcium present in the dose will actually get absorbed. Taking this constraint into account, is the level of Ca sufficient enough to rescue the Mg absorption that is blocked by the Zn? Input the amount of Ca²⁺ absorbed.

C) There are 5 L of blood in the human body. Blood concentrations of Ca between 0.0035 and 0.0040 mol/L indicate critical hypercalcemia. At this dose (the dose it takes to block Mg absorption), will the calcium kill the person taking the pill? Answer here with the molarity of Ca²⁺ resulting from ingesting the number of doses calculated in question A.

Behavioral changes in animals are strongly correlated to:

Provide an explanation in support of or refuting the following statement: Humans would never develop natural immunity to a novel biological agent created in a laboratory

Can you describe two dimensional model proposals that have been put forth in order to replace the current system of diagnosing someone with a personality disorder?  

This would NOT be found in mitosis:

Select one:

Cells with the same chromosome number and identical DNA

Sister chromatids

Centromere

Cells with reduced chromosome number with different DNA

Diploid cell

Clear my choice

This best describes a cell with homologous chromosomes:

Select one:

A condition where chromosomes are found in an abnormal number in a cell

A condition where chromosomes are unpaired, results in a haploid cell

A condition where one parent provides two chromosomes to an offspring

The chromosome condition in haploid (n) cells

A condition where chromosomes are paired, results in a diploid cell

Chiasmata are found:

Select one:

in Meiosis II

after interphase in mitosis

during anaphase

just after telophase

in Meiosis I

Clear my choice

1.) You are asked to prepare a gram stain from a mixture of gram positive and gram negative bacteria during lab. What would happen if you remembered all steps.... except to decolorize – what color would the Gram (+) and Gram (-) be? except to add safranin – what color would the Gram (+) and Gram (-) be?

2.) The organism Yersinia pestis causes the plague, which caused a pandemic in Europe. What test reults would you expect to observe if samples from a plague patient were analyzed using the gram stain, the endospore stain, the capsule stain, and the acid-fast stain? Include the expected shape of the cell, the color Y. pestis cells should turn for each stain, and if the result is positive or negative.