imagine you have been reduced to the size of an enzyme and delivered via a capsule by mouth into 82-year old Mary to find out why she has a loss of appetite. The goal is for the capsule to begin dissolving in the upper GI tract and for you to use your ship to explore Mary’s GI system for signs of disease. In a 500-word paper, describe what you see as you move through the GI tract and be sure to explore each organ and any enzymes you come across. When you are eliminated via feces, you will bring your notes to the physician for diagnosis and treatment options.

ErmTR is an enzyme found in S. pyogenes strains that are resistant to erythromycin. While working in the lab one afternoon you discover a small molecule (C23) that inhibits the activity of ermTR. To assess the type of inhibitor you discovered, you set up reactions with 6 different concentrations of erythromycin and varying amounts of the C23 small molecule you discovered. To each reaction you add 2 x 10-12 mol of ermTR (total reaction volume: 15 mL) and measure the initial velocities, Vo, by spectrophotometry. You obtained the following data:

Initial Velocity Vo (micromoles/min)

Display the data on a Lineweaver-Burk plot in order to extract the Km and Vmax values. You can
generate the plot by hand on the graph paper on the last page or use a program, such as Excel, to plot the data. Submit the plot you generate with your test answers.

b) What are the KM and Vmax values for each of the samples? Show your calculations and explain how you obtain the answer for the “no inhibitor” sample.

c) What type of inhibitor is C23? Explain your answer.

d) Calculate the turnover number and the specificity constant for the enzyme sample that lacks the inhibitor C23.

After the discovery of DNA polymerase by Arthur Kornberg, the properties of the enzyme became quite well known. One of the most critical is that all known DNA polymerases synthesize DNA only: 5' to 3'. This fact led to a dilemma regarding how the semiconservative model would work for a DNA molecule. Reiji Okazaki a brilliant experimenter took on this problem. [An aside: Okazaki was born near Hiroshima, Japan, in 1930. He was a teenager there at the time of the explosion of the first of two nuclear bombs that the US dropped at the end of World War II. Reiji's scientific career was cut short by his untimely death from cancer in 1975 at the age of 44]

In the actual experiment: They cultured E. coli (at low temperatures to slow down replication process) in the presence of radioactive nucleotides. They did this for short pulses followed by the addition of excess nonradioactive nucleotides. This resulted in label (radioactivity) being present only in the DNA that was synthesized during the short period of the pulse. Soon after the pulse, they isolated the DNA and separated the individual strands from one another. The various pieces of DNA could then be sorted out by size: using a “sucrose gradient” and spun in an ultracentrifuge.

3a- 2pts) Describe what types of DNA fragments he would have observed after short pulses? Indicate in your answer:

1. What the difference is between the fragments in terms of size
2. Based on your understanding of the process of DNA replication what the source of those

fragments would be.

(Use accurate terminology. We will be using a Rubric that looks for the accurate use of terms needed to answer this question)

Assume Okazaki and his team were unaware that their bacteria had a mutation in the gene that codes for DNA Ligase. Also assume that the mutation rendered the protein DNA Ligase unable to carry out its enzymatic activity/function.

3b- 1pt) What kinds of fragments would be seen after a short pulse when carrying out the assay with such a mutant? (0.5pt) Why? (0.5pt) (Answer in complete sentences)

3c- 1pt) What kind of fragments would be seen after a long exposure to the radioactive label? (0.5pt) Why? (0.5pt) Answer in a complete sentence

1.When the substrates bind to the active of an enzyme, the active site changes shape. This is an example of: a) lock & key model; b) inhibitor model; c) allosteric model; d) induced fit model; e) none.

2. The change in free energy at equilibrium is: a) increased; b) decreased; c) no net change

3. You have a gram of each of the following: bacon grease, lean ground turkey and bread. Which on has more potential energy and why? a) bacon/fewer bonds; b) turkey/more bonds; c) bread/less bonds; d) grease/more bonds; e) turkey/less bonds; ab) bread/more bonds; ac) all of these are equal; ad) none of them

1. A virus infects cells and uses them replicate (make copies of itself). What are all viruses composed of?

a. nucleic acid surrounded by a protein coat

b. DNA and RNA surrounded by a lipid membrane

c. RNA surrounded by protein spikes

d. genetic material surrounded by lipids and proteins

2. What is the structure of a coronavirus?

a. DNA wrapped in protein capsid, surrounded by phospholipid membrane with protein spikes on surface

b. RNA wrapped in protein capsid, surrounded by phospholipid membrane with protein spikes on surface

c.DNA wrapped in a lipid capsid, with protein spikes protecting the DNA

d. RNA wrapped in a lipid capsid, with protein spikes protecting the RNA

3. What is the function of the spike protein on SARS-CoV-2?

a. stimulates viral reproduction inside human cells

b. provides the genetic sequence for making new proteins

c. causes mutations in the viral genome

d. binds to ACE2 receptors on human cells, which then allow virus to enter cell

4. How did the coronavirus jump from animals to humans?

a. random mutations created new spike proteins that were now able to bind to human cell receptors

b. human cells selected for specific mutations in the virus

c. mutations in the viral envelope allowed the virus to enter into a human cell

d. ACE2 receptors on human cells mutated and can now bind to the coronavirus

5. There are a variety of approaches to making a COVID-19 vaccine. Which of the following statements concerning COVID-19 vaccine development is most accurate?

a. mRNA vaccines are the traditional route for vaccine development but are slower to make

b. using attenuated (weakened) versions of the virus are not a viable option for this vaccine because of the high risk

c. mRNA vaccines are a newer technology and less certain, but are currently in the clinical trial stage of development

d. mRNA vaccines stimulate the human body to make the entire coronavirus RNA sequence

(1)  One major kind of metabolic process is termed catabolic (catabolism). This process is _______­­­­­­­­­_________ and is __________________.

(A)  involved in breakdown and digestion; energy releasing (exergonic)

(B)  involved in breakdown and digestion; energy requiring (endergonic)   

(C)  involved in synthesis and building; energy releasing (exergonic)

(D)  involved in synthesis and building; energy requiring (endergonic)

(2)  Metabolic pathways  

(A)  involve intermediates                              (B) can be linear, branched, or cyclic   

(C)  consist of multiple steps                          (D)  all of the above

(3)  In your readings, you saw that cellular aerobic respiration has three major sub pathways. The sub pathway that results in the cleavage of glucose into two smaller units is called…

(A)  the citric acid cycle (the Krebs cycle)     (B)  the light dependent reactions     

(C)  glycolysis                                                (D)  the light independent reactions(

Please Answer All

Enzymes ___________.

A prokaryotic cell __________.

Osmosis is the diffusion of __________ through a permeable membrane from an area of high concentration to low concentration.

Glycolysis ___________.

A bacterium that does not use O₂ and is killed when O₂ is present is best defined as a _______.

QUESTION 39

The molecule that traps the sun's energy is 


QUESTION 42

Deleterious mutations increase the fitness of the organism.

True

False

QUESTION 47

The light-independent reactions of photosynthesis (Calvin cycle) take place in the 


QUESTION 48

Cellular respiration is endergonic.

True

False

QUESTION 49

The ATP and NADPH produced in the light-dependent reaction stage 


QUESTION 52

In glycolysis, the net profit of ATP from one six-carbon sugar is 


2 points   

QUESTION 53

Aneuploidy is the addition or deletion of a chromosome.

True

False

In ecology, a population is best defined as:

A. all members of any one species living in the same place at the same time.

B. all members of all species living in the same place at the same time.

C. individuals interacting with the environment

D. everywhere on the planet where life is able to exist

E. all organisms living in the same place and time along with the non-living components of the area.

In the planetary carbon cycle, carbon is returned to the atmosphere by

A. fermentation.

B. the light reactions of photosynthesis.

C. the Carbon (dark/light-independent/Calvin) cycle reactions of photosynthesis.

D. glycolysis.

E. aerobic respiration in animals.

A multicellular organism has cell walls, but cannot photosynthesize. Into which Kingdom would this organism be classified?

A. Fungi.

B. Protista.

C. Animalia.

D. Plantae.

E. Flagellata.