How did comparisons of different rRNA sequences lead to the discovery of Archaea? Why did Woese use rRNA genes to construct molecular phylogenies? Which groups are most similar (bacteria, archaea, and eukaryotes) with respect to the following structures or processes: cellular membrane biochemistry, DNA replication, RNA transcription, mechanism of protein translation, initiation of protein translation. Explain the argument that the most fundamental divide in the Tree of Life is between Bacteria and Archaea. Why is membrane composition cited as the basis of the ‘eukaryote paradox’? Know the arguments for discontinuing use of the term “prokaryote” and be able to explain why you think (or don’t think) that prokaryote is a useful and/or accurate term. How do Lateral Gene Transfers (LGT), aka horizontal gene transfer, confound reconstruction of phylogenetic trees? Name three processes of bacteria and archaea that result in LGT. How can we overcome this difficulty in understanding the (vertical) evolutionary history of microbes? What kinds of genes seem resistant to LGT? Explain the statement “we are embedded in a microbial world” – be sure to include the production of oxygen on Earth in your answer. Remember that thermodynamics tells us that energy flows out of all systems, but matter cycles. Much of the nutrient (matter) cycling that we all depend on requires microbial activity. Name the nutrient cycles that we described in lecture that require microbial activity. When did the plant- nitrogen-fixing-bacterial symbiosis emerge in earth’s history? Chlorophylls are an innovation of which group of organisms? Why is nitrogen limiting in most ecosystems?

let's imagine a diploid plant cell.

a) draw the five stages of mitosis and meiosis assuming N=3

b) briefly explain each step of mitosis and meiosis.

Chapter 1(microbiology)

5. What was the contribution of each of the following scientists: Jenner, Lister, Leeuwenhoek, Redi, Ehrlich, and Fleming.

6. What is spontaneous generation?

7. What was Pasteur’s approach to disproving spontaneous generation? What other discoveries did he make?

8. What are Koch’s postulates? What are the key features of these postulates? Be able to apply these ideas to a real life scenario. Explain when someone would need to follow the steps of Koch’s postulates?

9. Identify type of study performed by etiology, epidemiology, virology, mycology, parasitology, bacteriology.

CHEM 4722/5722 Homework Set #3 (due beginning of class Thu Apr 2)

Homework is to be turned in prior to class and should be done on plain white printer paper. If not, it will be returned for resubmission with a penalty assessed. Word processing should be used for any narrative answers. Calculations and mechanisms can be done freehand but must be very neat, organized, legible and on plain white paper. No lined paper will be accepted.

1. An example of a unsaturated fatty acid is cis-11-heptadecenoic acid. If this compound is oxidized down to CO2 and water via β-oxidation and subsequent pathways, how many ATP equivalents can be obtained? Show all work and list where all of the ATPs come from.

2. Draw out both steps of the malic enzyme mechanism for the conversion of malate to pyruvate. Include nicotinamide moieties, acid/base catalysis, and electron movement.

3. Write a balanced stoichiometric equation for the synthesis of squalene from acetyl-CoA. Indicate the reactions you used to determine your answer and show all work.

4. Refer to your lecture notes or your book for the synthesis of sphingomyelin. Write out the mechanisms (reactant, product structures and electron movement) for each synthetic step to the final product.

5. Mice were divided into four groups, two of which were fed a normal diet and two of which were fed a cholesterol-rich diet. HMG-CoA reductase mRNA and protein levels from liver were measured.

   1. a) What is the effect of cholesterol feeding on HMG-CoA reductase mRNA?

   2. b) What is the effect of cholesterol feeding on HMG-CoA reductase protein?

   3. c) Why is the result in panel B surprising in light of the result in panel A?

   4. d) Suggest possible explanations for the result in panel B.

IgM, unlike other heavy chain isotypes, appears in the serum as a pentamer of the basic four-chain Ig monomer; thus making it decavalent rather than bivalent in terms of combining sites. One intriguing result of this is an increase in the likelihood - all other things being equal - that the IgM will be bound (versus free). Another way of saying this is that even though the affinity constant (Ka) of each individual combining site is the same regardless of the overall molecule's valency, this decavalent version will have more whole Ig molecules bound (to antigen) at equilibrium than would a bivalent version (given equimolar levels of combining sites). This phenomenon is sometimes called increased "avidity" (to avoid using the rigorously defined chemical term "affinity" incorrectly). I'd like you to discuss a few issues raised by this:

• First, bearing in mind that IgM is the first isotype made during primary responses,why does this higher "avidity" make intuitive sense?
• Second, can you foresee ways that this added "stickiness" might also engender problems?
• Finally, does this mean that IgM molecules are more or less "specific" than their IgG counterparts? (watch it, that last one is tricky)

   Slide 11 problem:

   5’ UGG 3’ -  mRNA

                      -Template DNA stand

  -Nontemplate DNA strand

Slide 33 problem:

The following sequence of nucleotides in a DNA strand was used as a template to synthesize a mRNA that was then translated into protein:

                        5’-TTAACGGCTTTTTTCCAT-3’

Predict the C-term aa and the N-term aa of the resulting polypeptide.

Slide 34 problem:

True or False? Explain your answer!

1.An individual ribosome can make only one type of protein.

2.The large and small subunits of an individual ribosome

always stay together and never exchange partners.

3.An mRNA may contain the sequence ATTGACCCCGGTCAA

Slide 35 problem:

A mutation in DNA generates a UGA stop codon in the middle of the mRNA coding for protein X. You are studying protein X and isolating it from mutated cells. Which one best describes your findings:

1. No changes whatsoever are found between protein X isolated from wild type and mutant cells
2. Protein X from wild type cells is shorter than the one from mutant cells
3. Protein X from wild type cells is longer than the one from mutant cells
4. Protein X from mutant cells has a new function

what is the difference between long and short reflexes in the neural control of digestion? Put in more about enteric nervous system.

How does M-Cdk facilitate mitosis? (Hint: 4 targets)

How is M-Cdk turned off?

Explain what happens in telophase related to the M-Cdk targets and return of cell to interphase.

Write an introduction on "how vinegar and water solution affect the rate of seed germination".

the introduction should include :

1 - Relevant background information

2 - A clear stated hypothesis with justification

3 - You must include at least three literature citations ( use in-text citations and provide the full citations)

1. Nutrition is a broad field that involves the foods you consume, the nutrient content of those foods, and how those foods and their nutrients affect your health and wellness. Health effects can include how you feel on a daily basis, as well as your risk for certain diseases in the future.

Choose the option below that does not describe the science of nutrition.

2. Macronutrients are important sources of energy for the body. These include carbohydrates, protein, and fat, and are needed in relatively large amounts in the diet. Some foods contain only one macronutrient, but most foods contain a combination of these nutrients.

Choose the option below that is not a source of macronutrients.

3. Dietary Reference Intakes are a set of guidelines intended to help identify how much of each nutrient is needed. Following these guidelines may help prevent deficiency diseases, reduce the risk of chronic disease, and limit risk of nutrient toxicity.

From the statements below, choose the one that correctly describes one of the Dietary Reference Intakes.

There are three different questions with three different answers. Please answer all three questions.

Galactosemia is a recessive human disease that is treatable by restricting lactose and glucose in the diet. Susan Smithers and her husband are both heterozygous for the galactosemia gene. If Susan and her husband have four children, what is the probability that: (1 point each)

a. none of the four will have galactosemia?

b. at least one child will have galactosemia?

c. only one child will have galactosemia?

d. the first two will have galactosemia and the second two will not?

e. two will have galactosemia and two will not, regardless of order?

Please provide an explanation! This is my second time posting this so if you aren't sure please don't answer!! TY!