What properties of ions and their respective transmembrane channels make K+ channels selective for a specific ion? (Hint: focus on pore and the selectivity filter).

Researchers have identified a gene that, they think, encodes a voltage-dependent potassium channel. How would you go about trying to prove that it does encode such a channel?

1 Explain the meaning of the term mutarotation.

2 Draw the structure of a disaccharide made up of two D-glucose units. The glycosidic bond is

    α-1,6-glycosidic bond.

3 Trehalose is a disaccharide that can be obtained from fungi, sea urchins and insects. Acid hydrolysis of

    trehalose yields only D-glucose. Trehalose is hydrolysed by α-glucosidase and not by β-glucosidase

    enzymes. Methylation of trehalose followed by hydrolysis yields two molar equivalents of

    2,3,4,6-tetra-O-methyl-D-glucopyranose.

1.   From the following experimental data, deduce the structure of trehalose.
2. What will be the effect of trehalose on Fehling’s solution?

4(a) Suggest a test you will use to show that a given food substance contains protein.

2. Show how you will use

1. Modified Gabriel’s Synthsis
2. Streckers’s Synthesis   to prepare phenylalanine in the laboratory.

5 (a) Describe in detail how you will determine the primary structure of protein.

(b) You have been given a mixture of lysine, histidine and cysteine. The isoelectric point of the amino acids are as follows:

Histidine                        7.64

Lysine                             9.74

Cystenie                         5.02

Show how you will separate the mixture into the pure forms. State and describe any instrument that you will use to separate the components in the mixture.

6 (a) A decapeptide has the following amino acid composition:

         Ala₂ , Arg, Cys, Glu, Gly, Leu, Lys, Phe, Val

       Partial hydrolysis yields the following tripeptides:

       Cys-Glu-Leu + Gly-Arg-Cys + Leu-Ala-Ala+ Lys-Val-Phe + Val-Phe-Gly.

       Reaction of the decapeptide with 2,4-dinitrofluorobenzene yields 2,4-dinitrophenylysine. From the

       experimental data, deduce the primary structure of the decapeptide.

   (b) Suggest a scheme you will follow to synthesize the dipeptide Ala-Gly

With the aid of a simple generic diagram, identify and explain how the type(s) of chemical bonding stabilizes a secondary structure that is present in crystal structure of Yeast Hexokinase PII with the correct amino acid sequence

I can ferment glucose and can grow in anaerobic environment via fermentation of this sugar. I also produce purple color in a microbiological test to which oil is added to stimulate the formation of anaerobic environment.

1. What is the substrate of the enzyme, the presence or absence of which will determine whether the test, with the purple color, will be positive or negative

a) glucose            b) amino acid(s)               c) protein                      d) lipids

2. What is the indicator of the test media from question 13.

a) amylase    b) methyl green    c) ferric ammonium citrate    d) bromcresol purple     e) iron

3. What is the nature of the chemical reaction catalyzed by this enzyme?

a) hydrolysis of nucleotides                                   b) hydrolysis of proteins

c) decarboxylation of amino acids                        d) deamination of amino acids

I can not grow in a viscous environment. I don’t have DNAse.

4. What will be the color of the growth around me, if I lack these skills?

a) colorless       b) green              c) red                      d) black

5. I can remove amine groups from amino acids such as phenylalanine. What will be the color associated with my growth after the addition of the appropriate indicator?

a) colorless                b) green               c) red                           d) black

6. I am a test where no indicator is needed. I am whitish in color to begin with and when bacteria that grows on me makes the right enzyme, you could see a halo around its growth. What is my name?

a) lipase test                 b) Glucoronate test                 c) amylase test                         d) casease test

Take a recent drug advertisement from a journal and retrieve 2 journal references mentioned in the advertisement to determine if the truly support the claim in the ad ( see medscape.com/viewarticle/726442 for ideas to look for)

Monkey knockouts? ANDi is the first step on the path to developing a knockout monkey that could be a better animal model for studying diseases and their treatments. Genetically modified primates could potentially be used to study breast cancer, HIV, and any number of diseases. However, not everyone agrees that creating a knockout monkey should be a scientific goal. Some point out that mice, and even zebrafish, share the majority of human genes and have been used effectively in research. Others argue that a knockout monkey could present a threat to public health because a pathogen might leap from the study animals to the human population. Others are uncomfortable with the use of primates in any sort of research due to their close relationship to humans. What do you think? Should we press forward to develop a knockout monkey?

Is genetic engineering the only way to increase food production? Proponents of genetically modified crops argue that it is the only way to increase food production enough to deal with population growth. What are the pro’s and con’s to genetically modified crops, and do you feel the pro’s outweigh the cons or vice-versa? Are there alternative ways to increase food production that should be investigated to balance the use of GMO crops?

Provide a simple explanation as to how a virus might be generated in which more than one env protein can be incorpoorated into a retrovirus particle by considering the process of budding.

1. Bones are strongest in resisting compressive stress, why? Explain.

2. Bones are weakest in resisting shear stress, why? Explain.

Marla and Anthony enjoy hiking and mountain climbing. They want to know whether theIr 2 year old son, Spencer, will excel at these activities too. They send a sample of Spencer's, cheek cells to a company that offers genetic test for atlethic ability and request a test on the angiotensin I-converting enzymes (ACE) gene. Marla and Anthony had read a study about 40 elite British mountaineers, many of whom had a genotype that is rare among the general, non-mountain-climbing population. Look up what the gene does, and suggest how variants of it might affect athletic ability.

A. Do you think that the parents should decide which sports spencer tries based on the genetic test results? explain your answer.

B. How might variants affect athletic ability? explain

C. Should parents choose sports for their chlid based on genetic test results? Explain.

1. which antibiotics would you prescribed to a patient for a bacterial

infection caused by Ecoli _   _   _   _ _  _       and Staph               -'------------ and·why?

How can humans face the challenge of maintaining our ecosystem so that it can sustain diverse species? What role does understanding the impact of the formation of new species and the extinction of others play in facing this challenge? Will humans be just another primate to go extinct?

6. Two common sources of emerging diseases are mutations in disease-causing organisms that enable them to transfer from one host species to another, and invasions of disease-causing organisms into new ecosystems.

a. Briefly describe one example of each, ensuring you clearly label which is an example of invasion and which is transfer across species

b. Describe what is meant by the term antimicrobial resistance

c. Use one of the examples you gave in part a) to describe how the rate of evolution impacts the relationship between the disease-causing species and both the new and original species impacted by the disease.