Explore BrainMass
Share

Biological Chemistry

Calcium Signaling in Fertilization

Describe a well-controlled experiment to determine if the rise in internal free calcium observed in the cytoplasm of unfertilized sea urchin eggs in the presence of A23187 is due to in flux of calcium from seawater. Include experimental treatments, controls, and briefly describe experimental methods. Note: As mentioned in th

Immunology

1. A "constitutive" process is one that is always present or active, whereas an "inducible" process is one that requires some stimulus or event to trigger its activity. In your journal, name and briefly explain two constitutive parts or processes that protect vertebrates from elements of their external environment. 2. Injec

Fluoroacetate and the citric acid cycle

Why does fluoracetate cause citrate to build up in the Citric Acid Cycle? Why do glucose and glycolysis decrease and hexose increases? Why is it fatal? What about fluoroacetyl-SCoA instead in the CAC? Why is it blocking or inhibiting?

Yeasts.

Are yeasts better anaerobic or aerobic? Why?

Breakdown of glycogen

What is the difference between glycogen breakdown in liver and in muscle? - Release vs. consumption

Covalent Modification

The phosphorylation and dephosphorylation of proteins is a vital means of regulation. Protein kinases attach phosphoryl groups, whereas phosphatases remove the phosphoryl group from the target protein. What is the energy cost of this kind of covalent regulation?

Features of Chymotrypsin

How do I sketch the active site, including the catalytic triad? How do these three residue act to allow proteolysis? Can you briefly explain to me the features of the chymotrypsin active site and the mechanism?

Bradford Assay Errors

What are the possible errors when the Bradford assay is used for the protein determination?

Peroxidase Description Type Reactions

What are peroxidase? - Include a brief description of the general type of reaction they catalyze. - Describe a metabolic pathway from any organism (bacterium, plant, animal) that peroxidase is involved. - Include the name of the specific peroxidase, the components of the reaction catalyzed by the peroxidase and the name

Describing pH, pKa and Ionization

I need help with the following correlation: In the simplest terms possible, please. Describe how one would use the concepts of pH and pka to predict the ionization state of any given amino acid or its side chain in a protein.

Universal Priming Sequences

A 2500 base-pair long cDNA of unknown sequence was cloned into the MCS of a plasmid vector that has universal priming sequences adjacent to and on both sides of the MCS. On one side this is called the "forward universal priming sequence" and on the other it is called the "reverse universal priming sequence." Sanger sequencing

Function of fluoresence have pseudomonal fluorescent bacteria

These bacteria don't present much colour when viewed through the microscope, but the name must carry some indication of colour. Has the colour a specific function? What is the process by which the bacteria turn meat "off"? The proces by which the bacteria affect milk is outlined in text books, but the "meat" process seems to b

Using the data given in table below plot a Lineweaver-Burk plot

A) Using the data given in table below plot a Lineweaver-Burk plot b) Determine the Km and Vmax for the three sets of data c) Which inhibitor would the most effective at high substrate concentrations? d) Explain you choice Table 1 : Kinetics data for an enzyme catalysed reaction with and without the presence of

Maximum Growth Rate

Calculate the maximum growth rate (umax) and the specific growth rate (u) at t=10h dX/dt = unetX, when u is constant lnX-lnX0 = ut Attached is a word doc with the data

Tripeptide Properties

Tripeptide1: Tyr-Lys-Met Tripeptide2: Gly-Pro-Arg Tripeptide3: Asp-Trp-Tyr Tripeptide4: Asp-His-Glu Tripeptide5: Leu-Val-Phe Which one of the above tripeptides: a. is most negatively charged at pH7 b. contains the largest number of nonpolar R groups c. contains sulfur d. will have the greatest light absorbance at 280

Glycolysis Pathway questions

1) Glycerol can enter the glycolysis pathway by being converted to what? 2) How many molecules of ATP are used up in the glycolysis pathway? 3) How many pyruvate molecules are obtained from one molecule of glucose in the glycolysis pathway? 4) How many molecules of ATP are produced in the glycolysis pathway? 5) H

Saturation of Lipids - Bromine

If you add 1 drop of 5% bromine solution in hexane to 1mL each of 5% solution of lard, olive oil, and corn oil dissolved in hexane, what happens to the bromine that causes each mixture to turn colorless? If you continue adding drops of bromine to each, eventually the lipids change color. For our experiment it took 14 for lard

Saponification Water-Based Solutions

1) Since calcium and magnesium salts of fatty acids are insoluble in water, how would you expect this to affect the usefulness of soap in hard water? 2) If you were to make soap (using 4 grams of lard, 2 mL of 7.8 M sodium hydroxide & boiling it) and add it to the following and inverting, what would you expect to see as far

4 Problems

3 . Describe the role of each member of the "triad" in the mechanism of chymostrypsin. 4. Some enzymes show a bell shaped curve for enzyme activity versus pH. What conclusions can you reach about the nature and the function of groups in the enzyme? Name an enzyme which exhibits this characteristic. 7. In 1935, two famous

Biochemical pathway

You are studying a biochemical pathway in the bread mold NEUROSPORA crassa that is involved in the production of the compound C. You know that compounds A,B,D,E,F are required in this pathway, but you do not know the order in which they are synthesized. In order to study this, you isolate five auxotrophic strains that cannot syn

Synthesized triglycerides structural formulas

A normal well fed animal is given an intravenous injection of radioactive acetate labeled with 14C in the methyl group. By use of structural formulas indicate the carbon atoms that will be labeled most heavily in the newly synthesized triglycerides. Briefly justify your result.

NMR Spectrum and 13C Label

I need some help with this challenging question: 13C-NMR spectroscopy was used to detect (13)C-label accumulation in cerebral metabolites following the intravenous infusion of [1,6-(13)C]-glucose (Glc). The (1)H- [(13)C]-NMR method yielded high-quality (1)H-[(13)C]-NMR spectra. As a result, the (13)C labeling of [4-(13)C]-glut

Comparing Rates of CO2 Generation

The relative metabolic activities in an organism of glycolysis + the citric acid cycle vs. the pentose phosphate pathway + gluconeogenesis can be measured by comparing rates of 13CO2 generation upon administration of glucose labeled with 13C at C1 with that of glucose labeled at C6. Explain why this is possible.

Comparing Efficiency of Glucose Oxidation

Compare the relative efficiencies (in ATP's per mole of glucose oxidized) of glucose oxidation via glycolysis + the citric acid cycle vs. glucose oxidation via the pentose phosphate pathway + gluconeogenesis. Assume that NADH and NADPH are each energetically equivalent to three ATP's.