Assume that 40.0 mL of a 0.0250 M solution of the protonated form of the amino acid valine (H2A+) (Figure 1) is titrated with 0.100 M NaOH.

Part A

Calculate the pH after addition of 10.0 mL of 0.100 M NaOH. Express your answer using three significant figures.

Part B

Calculate the pH after addition of 15.0 mL of 0.100 M NaOH.

Express your answer using three significant figures.

Part C

Calculate the pH after addition of 20.0 mL of 0.100 M NaOH.

Express your answer using three significant figures.

1a. Histone acetylation (addition of acetyl groups) is associated with ___ gene expression. (mark your answer with an X)

            ___ decreased                         ___ increased

b. Why does acetylating histones have this effect?

c. Acetyl groups can be removed by what type of enzyme?

d. These enzymes (answer to c) are recruited by: (mark your answer with an X)

            ___ activators                          ___ repressors

1.Classify the following as relating to an active site, the lock-and-key model, or the induced-fit model.

an active site that has a rigid shape

an active site that adapts to the shape of a substance

the portion of an enzyme where catalytic activity occurs

2. Identify the nitrogen base and sugar in each of the following nucleotides.

dCMP

dAMP

dGMP

dTMP

2. Based on the results of the glucose test strips, under what reaction conditions did hydrolysis of sucrose occur?

3. Based the results of the glucose test strips, under what reaction conditions hydrolysis of lactose occur?

4. What do the results of the glucose test strips suggest about the enzyme specificity of invertase and lactase?

Which enzyme–substrate pair is CORRECT?

Group of answer choices

- methylmalonyl CoA mutase – 3-hydroxy-3-methyl-glutaryl CoA

- acyl CoA synthetase – acetyl CoA

- thiolase – 3-ketoacyl CoA

- hydroxymethylglutaryl CoA synthase – L-methylmalonyl CoA

- cis-Δ³-enoyl CoA isomerase – trans-Δ³-enoyl CoA

1. How does malonate affect the initial velocity of succinate dehydrogenase?

2. Explain why initial velocity varies directly with enzyme concentration, and how this related to the Michaelis Menten equation

3. How does malonate affect the initial velocity of an reaction?

4. What feature(s) of malonate makes it a competitive inhibitor of SDH?

Which of the following occurs in photoreceptors when they are exposed to the appropriate wavelength of light?

Explain the difference between nonspecific binding and specific binding using an indirect ELISA as an example. For this assay, assume that you are determining the titer of antibody against BSA.

You bind BSA to wells of a microtiter plate, add a dilution series of the antibody in question across the wells of the plate, then detect that antibody with an enzyme-conjugated antibody/chromogenic substrate pair.

Many pesticides work by inhibiting the action of acetylcholinesterase, the enzyme that normally breaks down acetylcholine within the neuromuscular junction. What effect would inhibition of acetylcholinesterase have on muscle tissue and why? What symptoms might you expect in cases of pesticide toxicity? What do you think is the most likely cause of death in these poisonings?