olenka

Hello I have a questions about isotopes and radioactivity. I have red that that isotope of carbon 14C can be placed at any position in the glucose molecule and then , measurement of radioactivity in the products will indicate the metabolic fate of the radioisotope. So, if glucose is labeled in one or more positions with 14C, and fed to fermenting yeast, which form or forms of 14 C-glucose would give the most radioactivity in CO2 and the least ethanol??? My second question is about arsenate. Arsenate is chemically similar to inorganic phosphate and is used by phosphate-requiring enzymes as an alternative substrate. However , inorganic arsenates are quite unstable and spontaneously hydrolyze. Arsenate is known to inhibit ATP production in glycolysis. Can somone explain me the mechanism of inhibition and identify the target enzyme please???? :confused::confused::confused:

1. Use Venn diagrams or membership table to demonstrates that: A U (B ∩ C)= (A U B) ∩ (A U C) is a true equation for any sets A, B, and C. If you use Venn diagrams , show the three circles overlapping and include a legend pointing out which set is represented by witch shaded regions. 2. Find the best conclusion for this Lewis Carroll problem . The "best" conclusion is one which uses all of the given information. A. No one who is going to a party ever fails to brush his hair. B. No one looks fascinating , if he is untidy. C. Opium -eaters have no self-command. D.Everyone who has brushed his hair looks fascinating. E.No one wears white kid gloves unless he is going to a party. F. A person is always untidy if he/she has no self -command. Assign letters to the statements , write the premises using logic symbols , write a valid argument which leads to the best conclusion , then write the conclusion in words. 3. Prove this statement : For all X ε { 2,4,6,8,12,10}, 3x +12 is an even number. Please help !!! Thanks(Headbang)

These R not The Homework Questions but anyway could you please give me any hints how to do them correctly? Thanks! 1. An Acid , HA has a pKa=4.7. Calculate the ratio [A-]/[HA] for the following values: a) pH=2.7 b)pH=3.7 c)pH=4.7, PH=5.7, pH=6.7 and pH=13.7 2. A buffer at pH 4.5 is made from a weak acid(HA) with pKa of 4.0. What is the ratio of [A]/[HA] in this buffer? The equilibrium equation for this buffer is HA<--> H+ + A-, Show how this buffer would act to mop up an influx H+ ions. 3. The pH increased from 5.8, the normal pH of a cigarette , to pH 6.4 by addition of ammonia. How many moles of ammonia are required to produce this pH change per cigarette (volume approx. 5ml) ? (Assume that no unprotonated ammonia will exist at pH 6.4) 4. Calculate the pH of normal arterial blood using the information given below: pKa= 6.1 for CO2 <--> H+ + HCO3- In arterial blood [HCO3-] =24mM , [CO2]=1.2mM Suppose the normal arterial blood is suddenly made to accept 11mM of HCl (aq): a) what is the resulting pH of the blood if no CO2 is allowed to escape? b)what is the resulting pH of the blood if 11 mM of CO2 can be quickly exhaled by normal processes? c) under these conditions , a person would actually begin to hyperventilate. how will this help to restore normal pH?

1. An Acid , HA has a pKa=4.7. Calculate the ratio [A-]/[HA] for the following values: a) pH=2.7 b)pH=3.7 c)pH=4.7, PH=5.7, pH=6.7 and pH=13.7 2. A buffer at pH 4.5 is made from a weak acid(HA) with pKa of 4.0. What is the ratio of [A]/[HA] in this buffer? The equilibrium equation for this buffer is HA<--> H+ + A-, Show how this buffer would act to mop up an influx H+ ions. 3. The pH increased from 5.8, the normal pH of a cigarette , to pH 6.4 by addition of ammonia. How many moles of ammonia are required to produce this pH change per cigarette (volume approx. 5ml) ? (Assume that no unprotonated ammonia will exist at pH 6.4) 4. Calculate the pH of normal arterial blood using the information given below: pKa= 6.1 for CO2 <--> H+ + HCO3- In arterial blood [HCO3-] =24mM , [CO2]=1.2mM Suppose the normal arterial blood is suddenly made to accept 11mM of HCl (aq): a) what is the resulting pH of the blood if no CO2 is allowed to escape? b)what is the resulting pH of the blood if 11 mM of CO2 can be quickly exhaled by normal processes? c) under these conditions , a person would actually begin to hyperventilate. how will this help to restore normal pH?

Tris is a widely used buffer in biochemistry and molecular biology research. Its molecular weight is 121.14g/mol. how many gram of Tris you need to male 1L of 1 M stock solution ? How many mL of water you need to make a 0.1 M Tris solution from 10 mL of 1M stock solution? If the 1 M Tris stock solution is labeled as 1000 X , what is the working concentration ? How many mL of stock solution you need to make 1 L of working solution? Please help me with this!!!!!

1. For [ ( p → q ) ʌ q ] → p make up the statement for p and one for q, then write a statement of this form in words to illustrate that this statement form is sometimes false. 2. The negation of statement form like pʌq can be written "not(pʌq)" or " it is false that pʌq" but these are considered trivial negations. A non trivial negation will change the form of the statement. For example using DeMorgans Law the negation of (pʌq) can be written (not p ᴠ not q). Using some of the logical equivalences on the tautology sheet write a non trivial negation of each of the following statements: a) If roses are red then violets are purple. b) Triangle ABC is isosceles or it is scalene C) A figure is a parallelogram if and only if it is a rectangle. :confused:Please Help