1.

a) A solution of 1 x 10^-8 M KOH (aq) is prepared. What is the pH of this solution?

b) A phthalate buffer is prepared in which [hydrogen phthalate]= 0.047 M and [phthalic acid] = 0.083 M. If the Ka1 of phthalic acid acid is 1.12 x 10^-3, and the Ka2 = 3.91 x 10^-6, what is the expected pH of the buffer?

c) The pH of a solution formed from a weak monoprotic acid (HA) is 3.1. If the formal concentration of the acid is 0.1M, what is the acids Ka value?

d) The pH of a saturated solution of a metal hydroxide (with formula M(OH)₂) is 9.85. What is the Ksp of M(OH)₂?

A tetrose has asymmetric carbon atoms in the D and L configuration in the second and third positions, respectively. What is the respective configuration of the tetrose?

a. β

b. L

c. α

d. DL

e. D

What lectin selectively binds to the endothelium?

a. E-selectin

b. P-selectin

c. hemagglutinin

d. L-selectin

e. erythropoietin

Some viruses gain entry into specific cells by:

a. attaching to ion channels.

b. cleaving the glycosidic bonds and altering protein shapes.

c. adding moieties of sialic acids to membrane proteins.

d. binding to glycoproteins on the cell surface that are unique to specific cells.

e. changing permeability of membranes.

Three flasks, labeled A, B, and C, contained aqueous solutions of the same pH. It was known that one of the solutions was 1.0 × 10–3 M in nitric acid, one was 6 × 10–3 M in formic acid, and one was 4 × 10–2 M in the salt formed by the weak organic base aniline with hydrochloric acid (C6H5NH3Cl). (Formic acid is monoprotic.)

(a) Describe a procedure for identifying the solutions.

(b) Compare qualitatively (on the basis of the preceding information) the strengths of nitric and formic acids with each other and with the acid strength of the anilinium ion,

(c) Show how the information given may be used to derive values for Ka for formic acid and Kb for aniline. Derive these values.

home / study / science / biology / questions and answers / which of the following best explains why atp is ... Question: Which of the following BEST explains why ATP is a ... Save Which of the following BEST explains why ATP is a positive regulator of aspartate transcarbamoylase (ATCase)? A. Aspartate is only available when ATP levels are high. B. ATP levels correspond to CTP levels, thus when both ATP and CTP are high, ATCase is active. C. Nucleic acids should only be produced when ATP levels are high. D. ATP always converts allosteric enzymes from the T state to the R state. E. None of the answers is correct.

3A. Using Table 11-3, Common Indicators, predict the color of Thymol Blue (note that there are 2 transition ranges for this indicator) at the following solution pH’s:

pH = 1.00 color__________

pH = 3.00 color__________

pH = 7.50 color __________

pH = 10.00 color

3B. Define the term “indicator error”:

3C: Explain why the first derivative of the titration curve can be used to identify the equivalence point of an acid-base titration (or equivalence p

3D: Explain the effect of pKa on endpoint detection for the titration of a weak acid with a strong base:oints for polyprotic acids).

3E: Explain the effect of acid strength (molarity) on endpoint detecton for the titration of a weak acid with a strong base.

The melting temperature for phospholipid membranes is strongly impacted by fatty acid composition and cholesterol contain. You have 3 different membranes. Membrane 1 is formed by phosphoglycerides with 2 chains of behenate

membrane 2 is formed by phosphoglycerides with 2 chains of stearate and membrane 3 is formed by phosphoglycerided with 2 chains of myristate. The structural properties of fatty acids are summarized in Table below. Which membrane (1, 2 or 3) has the lowest melting temperature and which membrane has the highest melting temperature. Explain your reasoning.

34. The myogenic reflex differs from a short reflex in which of the following ways?

a. The myogenic reflex is initiated by a stretch reflex

b. The myogenic reflex only involves one cell type

c. The myogenic reflex results in smooth muscle concentration

35. Which of the following is the most potent inhibitor of gastric acid secretion?

a. Somatostain

b. Gastrin

c. Acetylcholine

36. how do bile salts differ from lipases in digestion?

a. Bile salts help with fast digestion

b. Bile salts break bonds between fatty acids and the glycerol backbone

c. Bile salts can be recycled many times during a meal

During countercurrent multiplication, water is reabsorbed into the blood from the descending limb of the loop of Henle because

a. NaCl is transported out of the ascending limb

b. It is co-transported with Na+

c. Na+ is reabsorbed from the proximal convoluted tubule

d. Glucose is reabsorbed by the proximal convoluted tubule

e. Cl- is secreted into the distal convoluted tubule

2. A low salt (NaCl) diet is recommended for individuals with high blood pressure because

a. salt is the main cause of high blood pressure, so it needs to be consumed in low amounts.

b. extra Na+ in the diet causes blood vessels to stiffen which raises blood pressure over time

c. water follows Na+ and excess salt in the body will increase water retention and blood volume and thus, blood pressure

d. excess salt will force water into cells which may interrupt cell function or cause damage

e. excess salt will accumulate in blood vessels and block blood flow to tissues

3. To compensate for a state of acidosis, the kidney will

a. Increase H+ reabsorption to the blood

b. Slow metabolic production of acids like CO2

c. Slow the production of bicarbonate by tubular epithelial cells

d. Inhibit reabsorption of bicarbonate to the blood

e. Secrete H+ to the filtrate to be excreted

4. Chemical buffers

a. Only buffer the intracellular fluid and urine.

b. Eliminate excess acids or bases from the body.

c. Induce hypoventilation in response to abnormal carbon dioxide levels in the blood.

d. Only buffer the extracellular fluid.

e. temporarily tie up carbon dioxide or hydrogen ions until the lungs or kidneys are able to expel them from the body.