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role of the citric acid cycle as a central metabolic mechanism?

role of the citric acid cycle as a central metabolic mechanism?

Explain the role of citric acid cycle

Biology

Explain the role of the citric acid cycle as a central metabolic mechanism?

Explain what happens to the cells’ abilities to oxidize acetyl CoA when intermediates of the cycle are drained off for amino acid biosynthesis.

Describe the three steps in photosynthesis, detailing the interrelationships among them?

 

An action-potential signal to a postsynaptic neuron

An action-potential signal to a postsynaptic neuron

An action-potential signal to a postsynaptic neuron

Biology

It is known that calcium plays diverse roles in cellular processes. Upon increases in cytotoxic calcium concentration, calcium binds to proteins that have calcium binding sites, leading to the conformational change of the protein as well as changes in its biological activity. For in case, it is well established that in presynaptic neurons, the elevation of cytosolic calcium triggers the fusion of exocytotic vesicles that contain neurotransmitters to the plasma membrane.

A.) How does calcium trigger the fusion of exocytotic vesicles to the plasma membrane?

B.) How does the presynaptic neuron transducer an action-potential signal to a postsynaptic neuron

What is the mechanism of diversity in translation

What is the mechanism of diversity in translation

 

What is the mechanism of diversity in translation

Biology

Many of the larger DNA viruses are able to enhance viral protein translation by coding for ribosomes that selectively translate viral proteins?

 

a. True b. false

Question 2: A viral messenger RNA has the following sequence:

AUG AGU GGG GCC CAU GGG AAA CCC AGG UUU

The following proteins are produced:

MetAsnGlyAlaHisGlyLysProArgPhe

MetGlyAsnProGly

What is the mechanism that generates this diversity?

A. Polyprotein Synthesis

B. Leaky Scanning

C. Suppression of Termination

D. Ribosomal frameshift

Question 3: Some viruses are able to initiate translation at sites other than AUG(Methionine)?

a. True b. false

Question 4: A viral messenger RNA has the following sequence:

AUG AGU GGG GCC CAU GGG AAA CCC AGG UUU

The following proteins are produced:

MetAsnGlyAlaHisGlyLysProArgPhe…

MetAsnGlyAlaProTrpGluThrGlnVal…

What is the mechanism of diversity in translation of this viral mRNA?

Question 5: The genomes of (+) RNA viruses can be translated immediately upon cellular entry, even though they do not possess a 5′ 7-methylguanosine cap due to the presence of this structure at the 5′ end of the genome [x].

Question 6: Most viral infections induce activation of the eIF2a kinase PKR which halts protein translation in an infected cell. Which of the following mechanism enable viruses to evade the antiviral effects of PKR (Select all that apply)?

A. Viral protein inhibits eIF2a phosphatase.

B. Viral proteins inhibit dsRNA binding to PKR

C. Virus produces its own kinase that phsophorylates eIF2a.

D. Viral protein binds to PKR dsRNA binding site and activates PKR autophosphorylation.

E. Viral proteins act as pseudo-substrates that inhibit PKR kinase activity

 

discuss cytokinesis

discuss cytokinesis

 

Explain and discuss cytokinesis
Biology
Cytokinesis-the actual process of cell division-has attracted theorists for well over 100 years. It has been said that all possible explanations of cytokinesis have been proposed; the problem is to decide which one is correct.

Consider the following three hypotheses:

1. Chromosome signaling: When chromosomes split at anaphase, they emit a signal to the nearby cell surface to initiate
furrowing.

2. Polar relaxation: Asters relax the tension in the region of the cell surface nearest the spindle poles (the polar region),
allowing the region of the membrane farthest from the poles (the equatorial plane) to contract and initiate furrowing.

3. Aster stimulation: The asters stimulate contraction in the region of the cell surface where oppositely oriented spindle fibers
overlap (that is, the equatorial region), thereby initiating furrowing.

These hypotheses have been tested in a number of ways, One particularly informative experiment involved pressing a glass ball
onto the center of a dividing sand dollar egg so as to deform it into a torus (donut shape). As illustrated in Figure 17-35, the egg
divided into a single sausage-shaped cell at the first division; at the second division, it divided into four cells.

A. What does the chromosome-signaling hypothesis predict for the result of this experiment? Do the predictions match the experimental observations?

B. What does the polar-relaxation hypothesis predict for the experimental out-come? Do the predictions match the experimental observations?

C. What does the aster-stimulation hypothesis predict? Do the predictions match the experimental observations?

Describe the mechanism of action of antiarrhythmics

Describe the mechanism of action of antiarrhythmics

Describe the mechanism of action of antiarrhythmics

Biology
1. Briefly present the most common side effects of cardiovascular drugs. Why some of them can cause electrolyte abnormalities, dysrhythmias or drug-drug interactions. Give some examples.

2. Present the rationale for clinical applications of renin-angiotensin inhibitors. What are the major side effects?

3. What is a difference between centrally acting sympatholytics and peripherally acting sympatholytics? How can they be used in clinical practice?

4. Describe the mechanism of action of diuretics. Give a comparison of their pharmacokinetic parameters and site effects.

5. Describe the mechanism of action of antiarrhythmics. Give a comparison of their electrophysiological actions, clinical applications, drug-drug interactions and their site effects.

What products formed when nitroglycerin undergoes hydrolysis

What products formed when nitroglycerin undergoes hydrolysis

What products formed when nitroglycerin undergoes hydrolysis

Biology
1.What toxic substance that has a lethal dose of 2,000 to 5,000 ppm to laboratory animals has been detected in smoke from polymeric fires? __________.

Which of the following statements about polymer decomposition and combustion is INCORRECT?
The surfaces of some polymeric products tend to char as they burn.
Burning polymeric products are only capable of releasing minimal heat.
Burning polymeric products can evolve voluminous amounts of smoke, carbon monoxide, other hazardous gases, vapor, and fumes.
Polymers frequently undergo thermal degradation into simpler chemical substances

A substance that is added to a polymerization tank to prevent or reduce the speed of autopolymerization is called 1) __________. One specific chemical that is used for this purpose is 2) __________.

The substance produced by the condensation of a glycol and an organic di¬isocyanate is called __________.

Question 1. Which of the following statements is INCORRECT regarding cyclonite?

Cyclonite is sometimes encountered as Composition C-4, in which it is mixed with a gummy binder and hand-molded into a puttylike shape for use as a plastic explosive.
Cyclonite can be desensitized by mixing it with beeswax.
Cyclonite is prepared from hexamethylenetetramine, sulfuric acid, ammonium nitrate, and acetic anhydride.
Cyclonite is a possible human carcinogen.

Question 2. Which of the following statements is INCORRECT regarding regulatory agencies that have some responsibilities in minimizing risks associated with radioactive materials in the United States?

OSHA establishes radiation exposure limits to protect public health.
The U.S. Environmental Protection Agency establishes radiation exposure levels to protect public health.
The U.S. Department of Energy oversees the construction and operation of nuclear waste disposal sites.
The U.S. Nuclear Regulatory Commission regulates the private nuclear energy industry.

Question 3. When emergency responders suspect that a package may contain an explosive, which of these actions should they NOT do?

Try to identify the material first and call for backup.
Use robotic means to transfer the material into a total-containment device.
Take the material to an isolated location where it can be further examined or destroyed.
Let only specially-trained personnel handle the material.

Question 4. Which of the following statements is INCORRECT regarding a radiological dirty bomb?

The detonation of a radiological dirty bomb will not increase the background radiation to which the entire human population is exposed for a substantial time.
The detonation of a radiological dirty bomb could not produce the immediate mass casualties that are associated with the detonation of nuclear weapons.
The radiological dirty bomb can be detonated with the use of a timer or a cell phone.
The radiological dirty bomb may be charged with a biological or chemical warfare agent.

Question 5. Mercury fulminate is synonymous with:

a commercial name for the explosive whose chemical name is cyclotrimethylene-trinitramine, or hexahydro-1,3,5-trinitro-1,3,5-triazine.
a commercial explosive whose proper chemical name is N-methyl-N-2,4,6-tetranitroaniline.
a secondary high explosive whose proper chemical name is cyclotetramethylenetetra-nitramine.
the primary explosive mercury(II) cyanate, a substance whose chemical formula is Hg(CNO)2.

Question 6. The permissible exposure limit (PEL) over an 8-hr workday for trinitrotoluene and nitroglycerin are 1) __________ mg/m3 and 2) __________ mg/m3, respectively. Which of these explosives is more toxic? 3) __________.

Question 7. List two acute radiation effects caused by single-dose exposure to 3.0 Gy of radiation: 1) __________ and 2) __________.

Question 8. Potassium-42 is a radioisotope that nutritionists use to determine whether the body is effectively using potassium at the cellular level. The half-life of potassium-42 is 12.4 hours. Assuming that a patient’s cells assimilate all the potassium chloride tagged with potassium-42, approximately what percentage of the dose remains in 2.1 days? __________ .

Question 9. What are the products formed when nitroglycerin undergoes hydrolysis? 1) __________ and 2) __________.

Question 10. During the winter months, when the exchange of indoor and outdoor air is limited, 0.00002 mCi of radon is identified on average in each liter of air within a home. What is the World Health Organization’s (WHO) action guideline in pCi/L for protection against acquiring cancer from exposure to radon? 1) __________ Does this concentration exceed the WHO’s action guideline? 2) __________.

Question 11. Selenium-75 is used in medicine to assist in diagnosing pancreatic cancer and decays solely by electron capture. The product of its decay is __________.

Question 12. 1) __________ is a method used to compare the relative effectiveness of different explosives to accomplish a specific task. The detonation of 2.0 kg of tetryl has the same explosive power as 2) __________ pounds of TNT.

Draw the pedigree that shows the familial relationships

Draw the pedigree that shows the familial relationships

 

Draw the pedigree that shows the familial relationships

Biology

Question: Joseph and Jenny have come to a genetic counselor to determine their chances of having a child with myotonic dystrophy, a degenerative muscular disorder that appears at about 50 years of age and is inherited with the autosomal dominant allele D. The autosomal recessive allele d does not contribute to the development of the disease. Both Joseph and Jenny are in their thirties and neither shows any signs of the disease at present. Jenny’s grandmother (her father’s mother) has the disease. Jenny’s grandmother’s father (Jenny’s great-grandfather) did not have the disease. There is no history of myotonic dystrophy in Joseph’s family or in Jenny’s mother’s or paternal grandfather’s family.
Question: Draw the pedigree that shows the familial relationships described in the paragraph above. Use a circle to denote a woman, a square to denote a man and a filled symbol to show individuals who have myotonic dystrophy. In this pedigree, you are attempting to trace the inheritance of the D allele. Beneath each symbol, show the genotype of each individual as far as it is known. You may use blanks to indicate that part of the genotype is unknown, if applicable.
Question: What is the probability that Jenny is a carrier of the D allele?
Question: What is the probability that Joseph and Jenny will have a child with myotonic dystrophy?
Question: Out of 3 children born to Joseph and Jenny, what is the probability that 1 will have myotonic dystrophy?
Question: Out of 5 children born to Joseph and Jenny, what is the probability that at least one will have myotonic dystrophy?