Explore BrainMass

Biological Chemistry


(See attached file for full problem description) --- For problems 6-8, assume standard conditions of pH 7 and 25C, unless otherwise stated, and assume equilibrium constants in which any [H+] and [H2O] terms have been incorporated into the constant, i.e., you don't have to use [H+] in any of the calculations. 6. Th

Mutiple choice

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) In absence of oxygen, a yeast cell undergoes fermentation and uses 100 molecules of glucose. How much net ATP will be generated? A) 100 B) 36 C) 400 D) 300 E) 200 2) All the following statements pertai

Glactose sucrose fementation

Glucose and sucrose easily produced alcohol fermentation in yeast. Why didn't galactose and lactose? This was the virtual experiment. pH was set at 7 temperature 20 degrees C 20 ml of glucose was added to 1ml yeast 20ml or sucrose was added to 1ml of yeast 20ml of galactose was added to 1 ml of yeast 20ml of lact

pH of Glycine After Addition of Acid/Base

I need some help answering this questsion: If I had 1L of a 1.0M solution of glycine at the isoelectric pH (6.02) and I added 0.3 mol of HCL, what would be the new pH? What would be the pH if I added 0.3 mol of NaOH instead of the acid?

Peptide Bonds, Amino Acids and Chemical Structures

I need some help with biochemical questions: 1. How do you calculate the pH of a solution of lysine if the side chain amino group is 3/4 dissociated? 2. What is the isoelectric point of His? 3. For L-Ile, describe with drawings why it is 2S,3S? 4. What are the 6 atoms that are coplanar due to the resticted rotation about

Non-Covalent Interactions In Proteins

--Which non covalent interactions are most likely to be important in protein-protein interactions in aqueous environment? --What is the driving force for proteins that are embedded in lipid membranes?

Intracellular second messenger

What Intracellular second messenger is the primary regulator of the physiological response of photoreceptors to stimulus? AND What intracellular messenger is the primary regulator of adaptation of photoreceptors? Please explain, but most of all with the right answer and explanation!

Beta bends or reverse turns

The amino acid sequence shown below represents a portion of a peptide bond obtained from a large protein: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 His - Ile -Thr - Arg - Phe - Phe - Pro - Cys - Met - Gly - Glu - Ala - Ile- Pro - His - 16 17 18

Questions Based on the Action of Pyruvate

Hi, I need some assistance with the following questions: 1. The disease beriberi, which results from a dietary deficiency of vitamin B1 (Thiamine) is characterized by neurological and cardiac symptoms, as well as increased levels of pyruvate and alpha- ketoglutarate in the blood. How does a deficiency of thiamine account for


What is the purpose of ferementation after glycolysis? and.. Why use starved starved yeast rather than sugar fed yeasts for fermentation?

Signaling responses are investigated.

Why do signalling responses that require changes in proteins already present in the cell occur in milliseconds to seconds, whereas responses that involve changes in gene expression usually take hours? Ideas are shown.

Fatty Acid Complement in Bacterial Membrane

A bacterium is in the process of acclimating to a lower temperature environment. How would you expect the fatty acid complement in the bacterial membrane to change in response to the lower temperature? Why?

Calculating enthalpy change in an oxidation ratio

What is deltaE for the oxidation of ubiquinol by cytochrome c when the ratio of [QH2]/[Q] is 10 and the ratio of [cyt c3+]/[cyt c2+] is 5? cytochrome c (Fe3+) + e- <---------> cytochrome c (Fe2+) E'o = 0.254V Ubiquinone + 2H+ + 2e- <-----------> ubiquinol + H2 E'o = 0.045V

Life on Earth - 8 Short Questions.

Life on Earth - Biological Concepts from the Non-Science Major Perspective Quiz: (1 point each) 1. Describe the difference between and exergonic and endergonic reaction? 2. Why do environmentalists claim that an increase in forests, i.e. rainforests, will slow down the effects of global warming? 3. Explain how fats a

Oxidation of palmitate

Estimate the amount of energy a mammal can obtain from the oxidation of palmitate, in the liver under conditions of ketosis, relative to the amount obtainable under conditions of a balanced diet with adequate consumption of glucogenic fuels.

GRE subject Biochem

Discuss the feasibility of using methylation analysis to distinguish between each of the following pairs of carbohydrates: A) Maltose and Trehalose B) Maltose and Amylose C) Amylose and Cellulose

Forming Disaccharides

Question: How many different possible disaccharides can be formed between the pyranose forms od D-galactose and D-glucose? How many are non-reducing? I am really stuck on this question. I don't really understand these concepts at all.

Inhibitors: Irreversible and Reversible

Question: It is possible to distinguish between an irreversible inhibitor and a classical mixed type reversible inhibitor by measuring Vmax of the enzymatic reaction as a function of [E]t in the absence and presence of the inhibitor. What does the slope represent in each case? What does the X-axis intercept represent in

Analysing Properties of Pancreatic Serine Proteases

A major difficulty in investigating the properties of pancreatic serine proteases is that these enzymes, being proteins, are self digesting. The problem is less severe for solutions of chymotrypsinthan than for solutions of elastase or trypsin. Suggest an explantion for this observation? (Do not consider the zymogen activ

Net Charge of a Protein and Temperature

The table below indicates approximate values for these at 25C. For reference, the delta H(ionization) for Tris is 47kJ/mole. Group deta H (ionization)(kJ/mole) Asp 3.9 Glu 0 Lys 48 Arg 48 His 28 N-term 40 C- term 0 How will the net charge of a typical protein change upon lowering the temperature from 37C to 4C, base

Biophysics - Calculating deltaG

In one day the average person secretes about 2.5 litres of gastric juice into the stomach. The pH of the cells in the stomach lining that perform the secretion is about 7 (the same as for all cells) and the pH of the stomach is about 1. Thus, H+ ions must be moved against an H+ gradient. The free energy change for moving molecul

Energy Span of the Respiratory Chain

Please see the attached document. Thanks. Energy Span of the Respiratory Chain: Electron transfer in the mitochondrial respiratory chain may be represented by the net reaction equation: NADH + H+ + ½ O2 H2O + NAD+ (a) Calculate the value of ∆E'0 for the net reaction of mitochondr

Carbonic Anhydrase: Calculate Turnover Number

Please help with the following problem. Provide step by step calculations. Carbonic anhydrase of red blood cells, which has a molecular weight of 30,000, is among the most active known enzymes. It catalyzes the reversible hydration of CO2, which is important for the transport of carbon dioxide from the tissues to the lungs.

Single enzyme that will breakdown all proteins,lipids, and carbs??

A friend of yours has just received a new dietary supplement purchased online. The bottle states that the single enzyme it contains will break down all proteins, lipids, and carbohydrates in food we eat into smaller easily digestible pieces. the bottle also states that the enzyme is an "organic protein." has your friend been mis

Cleaning Products, Proteins and Macromolecules

Please help with the following problem. You are the owner of a company that sells cleaning products. The people in research and development have two new products for you to review. The first is a type of hand soap that they say cuts grease because "it is from lipid and like dissolves like." The second is a laundry detergent