Tuesday
March 28, 2017

Number of results: 96

BioChem
What is the pH of hydroiodic acid (HI)?
September 1, 2011 by Max

BIOCHEM
calculate the pH of 0.0076M KOH
September 7, 2007 by CHEM

Biochem
The pK of acetic acid is 4.76. Which statement is true at pH 5.0? [A^-] = [HA] [A^-] < [HA] [A^-] > [HA]
August 28, 2011 by Zack

biochem
What is the structure and net charges of Aspartate, Lysine and Alanine at pH 7.5
January 28, 2012 by age

biochem
ph is 4.6, pKa is 4.76 in a .15M buffer solution, what are the concentrations of acid and base?
September 17, 2012 by Lola

Biochem
Calculate the pH of the buffer system of 0.20M K2HPO4/0.25M KH2PO4
December 3, 2015 by Yeah

Biochem
Describe the steps (and the glassware used) to making 100 mL of a 1 M Tris pH 7.8.
September 1, 2016 by Kasei

Biochem
Describe the steps (and the glassware used) to making 100 mL of a 1 M Tris pH 7.8.
September 6, 2016 by Kasei

REPOST biochem
i don't understand this why can carboxyl and phosphate groups act as acids? as in, what makes an acid?
October 18, 2007 by J

chem-biochem
why should a transition state be strongly bound to an enzyme than a substrate or product?
September 4, 2016 by Anonymous

BIOCHEM
what are the problems created by using molecular oxygen as a recipient of the electrons from the oxidation of carbon compounds.
March 14, 2011 by DAN

biochem
If you were to place a bacteria that could form spores in a stressful environment, what would the cell morphology look like?
October 20, 2009 by chrissy

Biochem
Can someone please help me find, or know of any molecules that are at least 20 bases (carbons, nitrogens..) long and have 3 hybrids (sp, sp2, dsp)
December 28, 2006 by Kara

biochem
can someone help me write a balanced 1/2 rxn for the oxidation of glyceraldehyde-3-phosphate to glycerate-1,3-bisphosphate? I confused on where to put the electrons and how many are needed
December 3, 2011 by amy

biochem
How would I calculate blood glucose levels if using standard curve ...and I have three samples and their absorbence at 420 nm.
March 15, 2015 by em

biochem'
A flask contains 300 ml of 0.4M NaCl. ¿How many moles of NaCl are in 15ml?
March 14, 2016 by jess

Biochem
10ml of HCl acid titrate with 9.9ml of NaOH. What is the mass in grams of HCl?
August 3, 2010 by Amrik

Biochem
What is the pH and pOH a solution that was made by adding 400 mL of water to 350 mL of 5.0 x 10^-3 M NaOH solution?
September 2, 2011 by Max

Biochem
How many silver coins (weighing 26g each) would it take to provide 5 moles of silver(Ag).
September 27, 2011 by Anonymous

Biochem
I have to memorize the 20 amino acids and some nucleotides...do you know where I can find some mnemonic tips for this???
September 12, 2007 by Julie

BioChem
If you run an unknown sample and it is darker than your highest standard on your standard curve, what do you report as the concentration?
October 31, 2011 by Dreamland11

Biochem
What concentration of competitive inhibitor is required to yield 75% inhibition at a substrate concentration of 1.5x10-3 if Km=2.9x10-4 and Ki=2x10-5?
April 17, 2011 by Bradley

BioChem
Write the chemical equation for the reaction that occurs when you add NaOH solution to NaH2PO4/Na2HPO4 buffer solution
March 23, 2012 by Megan

biochem
I have 0.500ml of 3M ethanol and then I take 0.250ml of it and put it to 0.250ml of 0.06M phosphate buffer, what is the final concentration?
March 27, 2012 by trouble

Biochem
If .1ml of serum, 5ml of reagent and 4.9ml of distilled water are mixed together what is the dilution of the serum in the final solution
March 23, 2014 by Dave

Biochem 12
Calculate the energy released per gram of propane when it is burned in a combustion reaction. The chemical formula for propane is C3H8.
March 8, 2015 by Vikki

biochem
Many of today’s antibacterial drugs work by interfering with the growth of cell walls, why do these drugs tend to have little toxic effect on humans?
September 28, 2009 by chrissy

Biochem
calculate the volumes of 0.10 M acetic acid and 0.20 M sodium acetate that are needed to prepare 48-mL buffer solution with pH = 3.70. Ka for acetic acid is 1.75 x 10-5
April 22, 2011 by Iris

Biochem
Describe the relationships among the major components that maintain Ca homeostasis. (Identify all the major factors which are involved in Ca homeostasis).
May 22, 2015 by Stephanie

Biochem
When trying to purify a protein using column chromatography, what happens to the mass of the protein eluted from the column if you accidentally run it dry? Would it be more or less? Thanks.
October 18, 2010 by Nancy

Chemistry
Calculate the pH of a potassium phosphate buffer if the pKa of KH2PO4 is 7.2 and the acid-base ratio is 2:1 I took Chemistry 7 years ago and am in a review for a Biochem course I am takin. I do not remember the basics so any help with how to get started or what equations to ...
August 18, 2015 by Liz

help with chem biochem
You have a 1 ml solution containing 100 uM Ethanol, and 1 mM NAD+. You then add 1 mg of alcohol dehydrogenase. Assume all of the ethanol gets converted to acetaldehyde . a) What will the final concentration of NADH be in the solution?
September 11, 2013 by tracy

Biochem
A buffer solution is prepared by mixing 200 mL of 0.2 M salt solution and 400 mL of a 0.2 M acid solution. What is the concentration of the resulting buffer? ~what is the pKa?
November 19, 2012 by Dr. Nick

biochem
How can I convert a rate constant from mol to t/M.I have 0.00012 mol of AcH present at 5min .Know I want to calculate the concentration at this time ( [AcH]t / M ) . How would I work this out .Please help this is for a lab writeup for tomorrow .
November 30, 2014 by Becky

biochem
How can I convert a rate constant from mol to t/M.I have 0.00012 mol of AcH present at 5min .Know I want to calculate the concentration at this time ( [AcH]t / M ) . How would I work this out .Please help this is for a lab write up for tomorrow .
November 30, 2014 by Becky

biochem
How can I convert a rate constant from mol to t/M.I have 0.00012 mol of AcH present at 5min .Know I want to calculate the concentration at this time ( [AcH]t / M ) . How would I work this out .Please help this is for a lab writeup for tomorrow .
November 30, 2014 by becky

Biochem
Using stocks of 0.1 M KH2PO4 and 0.1 M K2HPO4 how much 0.1 M K2HPO4 is needed to prepare 20 mL of a buffer solution at pH 7.2. The pKa of phosphate is 6.82. I know to solve for the ratio using henderson hasselbach but im lots after that! 5.2=6.82+log(A/HA) 1.0024HA=A
September 19, 2016 by Ellen

BioChem
Given stocks of 1M lactic Acid (pka 3.86) at pH 3.5, 2 M NaOH, 2M HCl and water; how would you prepare 4 Liters of 0.05M lactic acid at pH 3.25. I know you use the Hendersen-Hasselbeck eqn, just not sure how to start. Please help.
October 29, 2015 by Michelle

Biochem
You prepare a 1L solution of 0.5 M imidazole. (pKa= 7.05). Calculate the pH of the solution after you add 0.1 moles of HCl. I need to create an ICE table. I also know I need to use the Henderson- Hasselbalch equation but I'm confused on what to plug in.
September 23, 2016 by Ashley

biochem
When making Aspirin, I know that sulfuric acid is used as a catalyst. But i was wondering 1.) if the reaction would happen without the cataylst and 2.) can other substances be used as a cataylst in this reaction?
January 24, 2010 by chrissy

Biochem
We will need 0.5L extraction buffer with 25 mM HEPES, 1 mM EDTA, and 1 mM DTT. Please calculate how many grams of each solute are needed. (HEPES 238.3; EDTA 292.2; DTT 154.2)
September 9, 2013 by Amanda

Biochem again
Thanks for answering the first one :) Here is another Calculate the amount of sodium acetate and acetic acid necessary to make 100mL of a 0.500 M acetate buffer that is pH 5.2. I believe I have the answer but I want to make sure I did the work correctly.
September 11, 2008 by bugbabe623

biochem
The pKa of butanoic acid is 4.87. A student mixes 120 mL of 0.45 M butanoic acid with 50 mL of 0.3 M NaOH and adds water to give a final volume of 1 L. What is the pH of the final solution? Please show you work.
August 31, 2015 by Kim

biochem
why do lipids less dense than proteins? PLEASE HELP ME ANSWER THIS QUESTION. it really makes me wonder because lipids are much larger molecule compare to protein molecule but why protein is denser?
February 22, 2016 by sheila

biochem
If I am given a solid chemical form of both the acid and the base, how do I determine how many grams of each I need to make 1L of a 25mM Tris-HCl buffer with acid concentration of 18.94mM, and base concentration of 6.06mM?
February 17, 2011 by Jenny

biochem lab
any help with any of these questions is appreciated. Why was lysozyme pipetted with the Drummond micropipetter? Why can we crystallize lysozyme at room temperature when most proteins require 4 degrees celcius? Why can lysozyme experiments be set up without preservatives needed...
April 30, 2008 by stew

Biochem
Calculate the amount of Tris(hydroxlmethyl)aminomethane(Tris) necessary to make 100mL of a 0.100 M Tris buffer that is equimolar in Tris-base (MW=121.1 g/mol) and Tris-HCL (MW= 157.6g/mol)
September 10, 2008 by bugbabe623

Biochem
HEPES, is a commonly used component of physiological buffers. The PKa of the protonated amino group of HEPES is 7.55 at 25C. Describe the preparation of 1.00L of 0.100M HEPES buffer, pH 8.00, from the sodium salt of the basic form of HEPES (MW 260.3), .0M HCL and deionized water
September 13, 2010 by Angel

biochem
Exactly 100 bacteria with a generation time of 30 min are introduced into fresh sterile broth at 8am and maintained at an optimum incubation temperature throughout the day. How many bacterian are present at 3pm? How many generation will take place by 5pm the same day?
September 24, 2009 by chrissy

BioChem
If you want to determine the actual salicylate concentration for a sample that gives you a darker color than the highest standard, you would need to make a dilution of it. If you dilute it by mixing .25 mL of sample with .75 mL of water and then find that this mixture has a ...
October 31, 2011 by Dreamland11

Biochem
Describe the one dehydration reaction in glycolysis. Include reactants, products, enzyme, and which step it is. I know that it is step 6 and I believe that the reaction uses glyceraldehyde-3-phosphate dehydrogenase to convert glyceraldehyde-3-phosphate into 1,3-...
April 6, 2009 by Jaime

Biochem
If the calibration curve for a Beer's Law plot of a protein assay had a slope of 0.433 when absorb acne, A, was plotted as a function of protein concentration, c, in mg/mL. The absorbance of an unknown protein sample was 0.345. What is the concentration of protein in this ...
December 6, 2013 by S

biochem
I need to create a 100ml buffer with a pH of 4.00 using 0.100M Benzoic acid (pKa = 4.20)and 0.180M sodium benzoate. What volume of each material do I need to make this buffer? I think I need to use pH=pKa + log(A/HA)but am not sure if that is correct. Any help would be ...
September 10, 2011 by amy

Biochem
Desribe the preparation of 2.00 L of 0.100M pH 9.00 glycine starting with the sodium chloride salt of zwitterionic glycinhe and 1.00M NaOh. If a reaction that generated 2.00 mmoles of base were carried out in 100 mL of the above buffer, what would be the final solution pH? ( ...
September 13, 2011 by Sandra

biochem
dna template of auc? dna template of met? would that be ATC or TAG? Met's rna temp would be AUG. so its dna is TAC? or ATG? im confused.
January 14, 2016 by sheen

biochem
Which of the following pairs of compounds would NOT make a hydrogen bond with each other? CH3 and H20 H20 and HF NH4 and HF H2O and CH3COOH all of the following would make hydrogen bonds
January 27, 2013 by Jen

Biochem
The theory of ATP synthesis by the ATP synthesis apparatus is called the _______ theory. I have no idea. Can some please help? Go to www.google.com and type in "ATP synthesis" without the parentheses. I think you will find your answer about four or five references from the top...
July 20, 2006 by shamaev

I don't know where to start with it? A tube is set up for radioimmunoassay containing antibody with a capacity for binding 1ug antigen. Both labelled (50,000 counts per ug) and unlabelled antigen are added to the tube. Work out a formula to calculate the amounts of counts ...
February 27, 2011 by Isabel

help with chem biochem
Ethanol + NAD+  acetaldehyde + NADH + H+  You have a 1 ml solution containing 100 uM Ethanol, and 1 mM NAD+. You then add 1 mg of alcohol dehydrogenase. Assume all of the ethanol gets converted to acetaldehyde.  a) What will the final concentration of NADH be in the...
September 11, 2013 by tracy

BioChem
1.Suppose you had a buffer containing 0.5 moles of sodium monobasic phosphate and 0.5 moles of sodium dibasic phosphate. How many moles of hydrochloric acid would this phosphate buffer be able to accept before the pH of the solution began to change drastically? Some Help would...
September 4, 2015 by Zaac

biochem
You have the following stock solutions and solid chemicals in your lab: 1.5M NaCL 0.2M Tris buffer, pH 8.0 10 mg/ml Bovine serum albumin (BSA) MgCl2 (solid, anhydrous) MW = 95.211 g/mole (95% pure) How would you make 250 ml of the following solution: 0.2M NaCl 0.05M Tris, pH 8...
March 10, 2013 by Shea

Biochem
what are the basic A.A when do protons dissociate Acid-base titration is performed, and the amino acid is found to have 3 distinct pKg values: 2.2 for the carboxyl group and 9.2 and 10.7 for the ammonium groups. At 1) pH < 2.2 2) pH = 9.2 -10.7 3) pH > 10.7 What is the ...
December 8, 2016 by sg

Biochem
For membrane-associated proteins, the consensus sequence _______ is found on the inchoate (new) polypeptide and ______ to halt. a. pribnow, replication b. signal peptidase, transcription c. stop-transfer peptide, transcription d. stop-transfer sequence, translation e. stop-...
August 1, 2006 by Sarah

BioChem
Please help with this question. Insulin, antibodies, enzymes and progesterone are four of many molecules found in and around cells. Of these four__________ are/is not a protein. a. antibodies b. insulin and antibodies c. antibodies and progesterone d. progesterone I think the ...
June 17, 2006 by Jamshid

biochem
How do you draw a tetrapeptide from the one letter codes(Amino acids) and also give the pI, if given the pKa values? For example the Amino acids: S,T,G,L So i know i decipher the the codes then to make tetrapeptide i start with the n terminus to the c terminus by adding the r ...
February 17, 2009 by jeff helper

Biochem
Using your results from the titration what mass of antacid is required to neutralized 25 ml of HCl. RESULTS: titration: mass of antacid:V of Hcl neutralized : 1:0.31.25.60 2:0.295.32.20 3:0.300.33.20
November 23, 2014 by anaaaam

Biochem
Glycerol 3-phosphate dehydrogenase catalyzes the reversible reaction: G3P + NAD+ --> NADH + H+ + DHAP If in the cell, the concentrations of G3P, NAD+, NADH, and DHAP are 2 mM, 4 mM, 6 mM, and 8 mM respectively. Determine if the reaction spontaneous as written? DHAP + 2e...
December 8, 2015 by Mia S

biochem
I mixed 4.50mL of 10.0mM NaOH with .50mL phenol red. I need to calculate the pH of this solution. I have more information in my lab but I am not sure what data I need to look for. As part of the experiment I calculated pKa of Phenol Red. Do I use that pKa in the henderson-...
September 20, 2011 by amy

Biochem (plz help)
The following data describe the binding of oxygen to human myoglobin at 37oC. P02 (mm Hg) = 0.5 1 2 3 4 Theta = .161 .277 .434 .535 .605 P02 (mm Hg) = 6 8 12 20 Theta = .697 .754 .821 .885 From these data, estimate: a). P50 b) the fraction saturation of myoglobin at 30 mm, the...
September 28, 2007 by Gulzaman

Biochem
5. The glass electrode used in commercial pH meters gives an electrical response proportional to the concentration of hydrogen ion. To convert these responses to a pH reading, the electrode must be calibrated against standard solutions of known H+ concentration. Determine the ...
March 12, 2013 by Anonymous

biochem.
why is it important for the intravenous fluids to have the same solute concentration as your blood? Answer: If the intravenous fluids did not have the same solute concentration, then the red blood cells would shrink, if the intravenous fluids were hypertonic or they would ...
September 23, 2008 by Lena

Biochem
I did a titiration expriment and I need to work out how much Hcl is in the sample (NaOH). The expriment was testing the rate of ester hydrolysis . I was wondering if the the amount of Hcl present is the same as NaOH added due to the equivalence of the acid and base but I also ...
November 30, 2014 by annnnnnnnnnnnnnnnnn

Biochem
You have prepared a 400 mL of a .210 M acetate buffer solution with a pH of 4.44. 1. Determine the concentration of both the acetate and acetic acid in the solution. 2. If you made this solution using solid sodium acetate (MW = 136 g/mol) and liquid acetic acid (17.6 M, ...
September 24, 2013 by Ross

Biochem
Assuming that the value of the equilibrium constant for the aldolase reaction Keq=6.43*10^-5 at pH=7 a.) What will be the equilibrium concentration of dihydroxyacetone phosphate (DHAP) if 1 mM of fructose-1,6-biphosphate is added to a buffered solution (pH=7) of aldolase? b.) ...
January 30, 2008 by Obert

chem biochem bio
You have the following stock solutions and solid chemicals in your lab: 1.5M NaCL 0.2M Tris buffer, pH 8.0 10 mg/ml Bovine serum albumin (BSA) MgCl2 (solid, anhydrous) MW = 95.211 g/mole (95% pure) How would you make 250 ml of the following solution??? 0.2M NaCl 0.05M Tris, pH...
March 10, 2013 by mel

Biochem
The mRNA sequence of nucleotides for gene "Y" has been determined to be AGCCAUGCCCGCGAGGUAGAAA. You have decided to mutate the gene, such that a new and functional protein is expressed from this gene. To do this, you have placed the nucleotide sequence_______ after the codon ...
July 20, 2006 by Shamaev

Biochem
Enhancers and promoters are ______. In contrast, the heterodimer "TFIIA and TFIIB" are examples of __________. a. trans-acting elements, cis-acting factors b. cis-acting elements, trans-acting factors c. cis-activating factors, trans-acting elements d. trans-activating factors...
August 1, 2006 by Sarah

Biochem
What is the maximum amount of ethanol (in millimoles) that could theoretically be produced under the following conditions? Condition: A cell-free yeast extract is placed in a solution that contains 3.50 × 102 mmol glucose, 0.30 mmol ADP, 0.30 mmol Pi, 0.60 mmol ATP, 0.20 mmol...
April 3, 2013 by Mark

Biochem
You wish to measure the ∆G°' for the hydrolysis of ATP: ATP --->ADP + Pi But the equilibrium for the hydrolysis lies so far toward products that analysis of the ATP concentration at equilibrium is neither practical or accurate. However, you have the following data ...
September 14, 2009 by Manny

Chemistry (or Physio/Biochem)
Asthma affects about seven percent of the population. During an asthma attack smooth muscle cells in the bronchi constrict, the airways become inflamed and swollen, and breathing becomes difficult. What effect might an asthma attack have on blood pH? A. pH goes down B. pH goes...
March 14, 2010 by Trixie

Biochem
In yeast, ethanol is produced from glucose under anaerobic conditions. What is the maximum amount of ethanol (in millimoles) that could theoretically be produced under the following conditions? A cell-free yeast extract is placed in a solution that contains 2.50 × 102 mmol ...
October 30, 2013 by B

BioChem
In yeast, ethanol is produced from glucose under anaerobic conditions. What is the maximum amount of ethanol (in millimoles) that could theoretically be produced under the following conditions? A cell-free yeast extract is placed in a solution that contains 2.50 × 102 mmol ...
October 30, 2013 by B

Biochem
Griffith's experiments along with Avery, MacLeod and McCarty helped to determine the transforming factors of Pneumococcus bacteria. Using heat-killed S-strain bacteria and one particular fraction of the cell lysates, they were able to demonstrate that _____ and not ______ was ...
July 22, 2006 by Sara

Biochem
1 ml of whole blood is collected and centrifuged to obtain a plasma sample. The volume of the plasma sample is 600 microlitres. A 1 in 4 dilution of the plasma is made and analysed using a cholesterol assay like the one you performed in the laboratory. 10 microlitres of both ...
September 30, 2012 by Liv

Biochem
1 ml of whole blood is collected and centrifuged to obtain a plasma sample. The volume of the plasma sample is 600 microlitres. A 1 in 4 dilution of the plasma is made and analysed using a cholesterol assay like the one you performed in the laboratory. 10 microlitres of both ...
September 30, 2012 by Liv

Biochem - Diabetes
Type 1 diabetic injected insufficient insulin so her body can’t use glucose in blood. Blood glucose is 38 mM (normal value = 3.3-5.8 mM). To adjust osmolality, she increased urine output = dehydration. Should she be treated with water? The answer is NO and my teacher said ...
February 27, 2011 by Lena

biochem
I'm stuck on this question, not sure where to start. can you show detail and explain so that it helps me to understand it. help please, thanks. The value of delta G for the conversion of 3-phosphoglycerate to 2-phosphoglycerate (2PG) is +4.4kj/mol. If the concentration of 3-...
February 9, 2013 by frank

bio
so the question is : List three different factors which influence the rate of enzyme activity and specifically explain each factor’s influence on enzyme activity. My answer: Since enzymes are proteins, they are very sensitive to environmental conditions. The very nature of ...
June 29, 2006 by bobs

Biochem
November 13, 2014 by Pop

Biochem
The number _____ and _____ sign are assigned to the first nucleotide of a transcriptional unit. a. 0, positive b. 1, negative c. 1, positive d. 0, no sign No idea what the answer might be. Since this is not my area of expertise, I searched Google under the key words ""first ...
August 1, 2006 by Sarah

BioChem
I have a hard time with this question. Please help. One way to determine the concentration of protein in a solution is to perform a "protein assay". There are several assay kits on the market that one can use, but they all rely on the common paradigm that the aromatic amino ...
June 17, 2006 by Jamshid

Chemistry (Biochem)
I'm given two pictures looking down the alpha helices of a coiled coil dimer of alpha-keratin. I'm asked to identify three statements out of the following that are true. My guesses are 2, 3, and 6. 1. Leu-Glu-His-Val-Cys-Lys-Ser is a likely repeat in the α helix of ...
January 27, 2013 by Robert

yo help!
k PGAL may be converted to glucose phosphate right? what other products can be produced???? Glyceraldehyde 3-phosphate can be converted to dihydroxyacetone phosphate, and these two molecules can be joined by aldolase to form fructose 1 ... glyceraldehyde 3-phosphate can be ...
July 25, 2006 by big head

chemistry!!!Need helpp!!!
Acid base Chenistry Homework help!? Histidine was electrophoresed in polyacrylamide at pH 6.0 with alanine (pI=6.0) and arginine (pka's 2.2, 9.0, and 12.5). At the end of the experiment, arginine had migrated toward the cathode 6.0 cm, alanine was still at the origin, and ...
September 23, 2007 by Mae

Biochem
The Na –glucose symport system of intestinal epithelial cells couples the \"downhill\" transport of two Na ions into the cell to the \"uphill\" transport of glucose, pumping glucose into the cell against its concentration gradient. If the Na concentration outside the cell ([...
November 2, 2013 by MIaow

Biochem
I can't figure out the correct answer for this, please help. The drosophila embryo goes through a series of mitotic divisions before cytokinesis occurs. This demostrates one of the following. 1: cytokinesis is inextricably associated with mitosis 2. mitosis is always followed ...
July 31, 2006 by Sarah

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