Food science question

Q: a small package with a surface area less than 200cm2 needs the following labelling:

A.just ingredient. B, none, C. just the name of the food; D. just allergens

1. What happens when you inhibit Wnt signaling in a center piece of a planarian worm (ie it had both its head and tail removed)?

A. Regeneration is inhibited

B. two tails form

C.two heads form

D. a head and tail form

2. Classification of the barnacle as a crustacean based on its larval form is an example of:

A. Adaptation to environmental conditions

B. unity of type
C. both A and B

3.Chronologically order the following stages of limb regeneration

- Differentiation of the blastema cells into the tissues of the regenerate

-Pattern formation in the regenerate

-Establishment of the wound epithelium over the site of injury

-Innervation of the wound epithelium

-Dedifferentiation of the mature limb cells into blastema cells

-Establishment of the AEC signaling center

As part of development of a new test for detection of misuse of human erythropoietin (EPO) by world athletes, Sydney researchers have studied the signals arising from native and administered EPO within 2D gels of urine samples. “The amino acid sequence of endogenous human erythropoietin (EPO) and (rEPO) is identical and consist of 165 amino acids, with three N-glycosylation sites and one O-glycosylation site. This gives an apparent molecular weight of 34 kDa by SDS-PAGE of which approximately 40% by weight is sugar content. Different micro-heterogeneity in glycosylation profiles (in particular, the number of sialic acid residues attached and the length of the sugar chains) between EPO and rEPO gives each form of the protein a different series of isoelectric points (pI) and a small change in molecular mass. The experimentally determined pI ranges are approximately 3.7–4.7 and 4.4–5.1 for EPO and rEPO, respectively. …. Analysis of unknown urine samples was carried out by two-dimensional electrophoresis. Total separated urinary proteins were visualized on the gel with SYPRO Ruby (Molecular Probes, USA) per the manufacturer’s instruction. After cutting the protein spots, the protein was digested by adding trypsin dissolved in 50 mM ammonium bicarbonate and incubated at 30o C overnight. The peptide solution was desalted, concentrated and spotted onto a MALDI plate alpha-cyano-4-hydroxy-cinnamic acid dissolved in 70% (v/v) acetonitrile and 0.1% (v/v) trifluoroacetic acid. MALDI-TOF MS was performed with an Axima CFR instrument (Shimadzu Kratos, UK), equipped with N2 laser (337 nm, 10 Hz repetition rate).”

Identification of other abundant urinary proteins pH range 3-7 is given below :

Tamm Horsfall glycoprotein (THP) – with mass (Da) 69715 and pI 5.05

Alpha-1-antichymotrypsin (AC)   - with mass (Da) 47651 and pI 5.3

Alpha-2-thiol proteinase inhibitor (PI) - with mass (Da)   71946 and pI 6.3

Alpha-2-HS-glycoprotein precursor (HSGP) - with mass (Da) 39325 and pI 5.4

Questions.

(a) Suggest the actual types of amino acid sidechains subject to glycosylation in EPO.

(b) Different rEPO products are currently available.

(i) Why might these products differ from one another in sugar content and structure?

(ii) Give two reasons why this chemical difference affects the 2D gel behaviour of the isoforms present

(c) Why are the protein components shown above have such a high precision of mass accuracy?

Note:

Please give explicit and comprehensive explanation .

Although multiple molecules are important in modern molecular labs, in Genetics Lab, we will be focusing on DNA. Throughout the semester, our treatment of the DNA can determine if we are successful or not in meeting our experimental goals.  

You are going to consider several treatments that might affect DNA shape/form/function. We use some of these treatments on purpose in order to manipulate our DNA, but sometimes we avoid these treatments to keep from harming our DNA.

You will be considering these treatments across three types of DNA:

1. pUC19 - pUC19 is a closed-circle plasmid (2686 bp) which used in molecular cloning
2. Lambda phage - Linear DNA from a bacteriophage (viruses that infect bacteria - in this case E. coli). Lambda phage is approximately 45,000 bps long.
3. Mammalian DNA - Eukaryotic mammalian DNA is arranged in very large linear chromosomes. Although this DNA is mechanically sheared to some extent during extraction, there are still pieces that may be hundreds of thousands of bps long.

You will consider what the following treatments could do to the DNA listed above:

1. Severe agitation - aggressive mixing with a votex machine
2. NaOH - treatment with a base
3. High heat - heating to 100^oC
4. Nuclease treatment - treatment with endo- or exonucleases

Think about the structure of the DNA. Hydrogen bonds are holding the bases together, while phosphodiester bonds are holding the sugar-phosphate backbone together.

• Which treatments will break the hydrogen bonds (and denature the DNA-reduce it from double-stranded DNA (dsDNA) to single-stranded DNA (ssDNA)?
• What treatments might break the DNA into pieces (fragmentation).
• Do you think that all of the types of DNA will be affected the same, or will certain treatments affect certain types of DNA more?

Consider the above questions and write out hypotheses for each treatments. Make sure to also address whether or not you think the different types of DNA will have different results.

Explain how Agrobacterium, CRISPR-Cas9, and RNAi are all used to genetically engineer plants for our benefit. What are some applications of these strategies? What are some causes for doubt?

A diploid organism produces four gametes from one parent cell through the process of meiosis. Two gametes are found to have 4 chromosomes, one gamete is found to have 3 chromosomes and one gamete is found to have 5 chromosomes. A) Is this the expected number of chromosomes that would be found in each gamete following a normal cycle of meiosis? If yes, explain why. If no, explain why not and describe how the gamete situation described above occurred. B) Determine the number of homologous chromosome pairs that the original parent cell contained, before meiosis began. Explain how you determined this value.

Explain how Agrobacterium tumefaciens causes crown gall in plants. Why is it called a “natural genetic engineer”?

In humans, is puberty a form of metamorphosis? Whether your answer is ‘yes’ or ‘no’, build a detailed case for your position. Genotype, phenotype, anatomy, physiology, underlying molecular mechanisms, and more, can be used in support of your answer.

In the case of Jesse Gelsinger, a young man who died during gene therapy, the therapy involved delivery via a viral vector. Was this germ-line or somatic therapy?

Draw a Michaelis Menten graph to represent normal pyruvate carboxylase kinetics in the conversion of pyruvate to oxaloacetate. Explain why you drew things as you did.

Which of the solutions below is hyperosmotic, isoosmotic, and hypoosmotic relative to the Red Blood Cells (RBCs) BEFORE and AFTER blood is added?

0.15 M Urea

Before:

After:

What is the osmolarity before and after blood is added?

0.3 M NaCl + 0.3 M Urea

13. Imagine a large inland sea located in a semi-desert region that supports a booming fishing and shipping trade. Through various lines of research, the following facts about this sea have been uncovered: .

e. Thirty years ago, upstream irrigation systems were introduced to supply surrounding farms.

a. About twenty years ago, the water level of the sea began to drop noticeably. Today, over half the water volume has been lost.

b. Salt content of this inland sea has nearly doubled. Strong winds are blowing the salt, which accumulates along the shore, into nearby agricultural lands.

c. Pesticides and other chemicals used in agriculture and adjacent industries have seeped back into the sea.

d. The lack of proper sewage facilities has resulted in the dumping of waste into the sea.

what effects would you expect these factors to have on this ecosystem? Explain your answer. What would you propose as solutions to this potential ecological catastrophe?

1. What non-covalent interactions can (1) Alanine and (2) Threonine acid participate in, as part of tertiary structure at pH 7? Include an explanation of the charges involved (full or partial, permanent or temporary)?

2. Suggest one amino acid whose side chain can participate in a non-covalent interaction with the side chain of alanine, and one amino acid whose side chain can participate in a non-covalent interaction with the side chain of threonine.