How do changes in pH affect the activity of an enzyme?

When DNS is added to your tubes, in the amylase activity experiment, what becomes reduced and what oxidized?

You take 400 μl of a stock solution of maltose of 4 mg/ml and mix it with water to make a final volume of 1000 μl. What is the final concentration of maltose in the tube now?

How can we calculate the retention factor (Rf) in chromatography?

1. The effect of an inhibitor on an enzyme was tested and the experiment gave the results below. Plot on Excel the data using a double-reciprocal plot (Lineweaver-Burke), determine K_m and V_max of the no inhibitor and each type of inhibitor and the type of inhibition that is occurring.

[S] µM      V (µmol/min) V (µmol/min) V (µmol/min)

                  with 0.0 nM    with 25 nM     with 50 nM

                  Inhibitor          Inhibitor          Inhibitor

______      ___________ ___________ ___________

                     0.4          0.22                0.21                 0.20

                     0.67        0.29                0.26                 0.24

                     1.00        0.32                0.30                 0.28

                     2.00        0.40                0.36                 0.32

Find the pH of each of the following solutions of mixtures of acids.

A)0.115 M in HBr and 0.120 M in HCHO2
Express your answer to three decimal places.

B)0.165 M in HNO2 and 9.0×10−2 M in HNO3
Express your answer to two decimal places.

A 0.21 M solution of a weak base A‑ is made. To a limited extent, the A‑ reacts with H2O to form some OH- and some of the corresponding weak acid HA. If the weak acid has a pKa of 9.4, what will be the pH of the solution (to the nearest hundredths)? For a hint see the Acids and Bases handout on Canvas.

Discuss the effect of (a) cholesterol addition, (b) free fatty acid addition, and (c) lysophospholipid addition to a membrane bilayer. Be sure to include an explanation of concentration dependence in biochemical and physical terms. Will your answers to (b) or (c) change if you consider saturated versus unsaturated fatty acids?

Chapter 7 is about Acids and Bases and Chapter 8 is about Oxidation Reduction. Write on one topic Antacids or Batteries. Choose 4 products, check the labels, list the active ingredients, and discuss in reasonable detail its use, side effects or toxicity, precaution and proper disposal

For each of the following side chain interactions in a protein, give an example of two amono acids that interact that way and draw a structure that illustrates the interaction.

a. Hydrophobic interaction, b. Metal ion coordination, c. Covalent bond (in the side chain), d. Hydrogen bonding, e. Salt bridge

One file java program that will simulate a game of Rock, Paper, Scissors. One of the two players will be the computer. The program will start by asking how many winning rounds are needed to win the game. Each round will consist of you asking the user to pick between rock, paper, and scissors. Internally you will get the computers choice by using a random number generator. Rock beats Scissors, Paper beats Rock, and Scissors beats Paper. You will report the win, loss, or tie and continue with another round. Repeating until either the user or the computer has won the correct number of times first. Please output what the user and computers choice is each time and give a running score total as the game goes on.

Output should look like:

Welcome to my game of Rock, Paper, Scissors!
How many winning rounds are needed for victory? :3

Round# 1
Enter 0=rock, 1=paper, 2=scissors:0

Human : Rock Computer : Rock
Draw, try again
Total Score: Human 0 Computer 0

Round# 2
Enter 0=rock, 1=paper, 2=scissors:1

Human : Paper Computer : Rock
Human wins this round
Total Score: Human 1 Computer 0

Round# 3
Enter 0=rock, 1=paper, 2=scissors:2

Human : Scissors Computer : Paper
Human wins this round
Total Score: Human 2 Computer 0

Round# 4
Enter 0=rock, 1=paper, 2=scissors:0

Human : Rock Computer : Rock
Draw, try again
Total Score: Human 2 Computer 0

Round# 5
Enter 0=rock, 1=paper, 2=scissors:0

Human : Rock Computer : Scissors
Human wins this round
Total Score: Human 3 Computer 0

It took 5 rounds, but you won!
Goodbye, play again sometime

14. Contemporary organisms on planet earth encode their design information using nucleic acids polymers that have four different monomers. These monomers are read three at a time to produce tool polymers – made up of a different kind of monomer. [This is a straightforward case of combinatorial coding of information.] This means that the number of different monomers in the tool polymer could, in principle, be 64. In practice, this number is actually 20 – because different nucleic acid monomer triplets (called “codons”) are read as NOT different. [Such codons that are not distinguished from one another are said to be “degenerate”.] If nucleic acids had three different monomers instead of four, triplet codons could encode 27 different tool monomer units, in principle. This would be plenty of coding capacity for the 20 different tool monomers that are actually used. In view of this, which of the following is the most likely explanation for the fact that contemporary organisms use four NOT three nucleic acid monomers?

1. It is an historical accident, of no mechanistic importance.
2. There were originally more than 27 tool monomers, but some have been lost in the evolution of contemporary organisms.
3. Double stranded nucleic acids (like the DNA double helix) wouldn’t be stable with only three different bases.
4. The requirement that nucleic acids replicate themselves means that they must have an even number of monomers (2, 4, 6, etc).

15. When an organism has two copies of each piece of design information, we refer to this state by which of the following terms? (Choose the most specific term.)

1. haploid
2. diploid
3. asexual
4. somatic

16. When an adult sexual organism (“parent” here) makes a gamete (egg or sperm) she/he places one copy of each chromosome into the gamete. This chromosome is chosen at random from the two copies this parent has – one received, in turn, from its father and one from its mother (the “grandparents” here). This process of choosing one of these two chromosomes is referred to specifically by which of the following technical terms?

1. crossing over
2. recombination
3. independent assortment
4. random mating