Wednesday, February 25, 2009

TQT Time

Bios,

Please submit your TQTQs for this week as a response to this post. Look ahead in your text and look at the LAC operon in bacteria and gene expression in eukaryotes for inspiration. A test looms, I just am not sure when.

Mr. Baker

13 comments:

Shauna said...

Geez, how I am the first one to post?
anywho...
1. Will the parent generation keep producing mutated genes? ( is it more likely)
2.Why does transfer RNA have the base uracil instead of thymine?
3.Is mRNA built like a lagging or leading strand? Does it matter?

Bulgan said...

1. If TMV is infected to any kind of plant that humans eat, would it die? Would humans get the virus if we eat the infected plant?
2. Why does RNA virus require their own supply of a certain enzymes?
3. What is the difference between viroids, prions and viruses?

Ana said...

1. How does the ras gene produce the g protein?
2. What does Differentiation do?
3. I just recently saw a story on primordial dwarfism... Could that have to do with genes??

Ca said...

1. In the process of protein synthesis, what determines whether a ribosome will be bound to ER (Endoplasmic Reticulum) or free in the cytoplasm?
2. What are capsomeres?
3. Can viruses make protein on their own?

Mr. Baker said...

Well I have a few minutes here so I will tackle a few of the TQTQs.

Shauna asked, "Will the parent generation keep producing mutated genes?" Not necessarily, each time a gamete is produced there is a chance it will include a mutant gene and the probability does not change if a mutant gene was produced in the preceding generation.

Shauna asked, "Is mRNA built like a lagging or leading strand?" Recall that mRNA is a single-stranded molecule and because of this it does not encounter the lagging strand problem.

Bulgan asked, "If TMV is infected to any kind of plant that humans eat, would it die? Would humans get the virus if we eat the infected plant? The best answer to both of these questions is that typically, viruses can infect only very specific hosts. So the TMV infects only tobacco and could not infect us.

Bulgan asked, "Why does RNA virus require their own supply of a certain enzymes?" This is because viruses are not cells and do not have all the "machinery" to make enzymes thus they need to infect cells and use their "equipment" to make more virus particles. Viruses infect cells by injecting their nucleic acid which is used to code for virus parts. So viruses can not make protein on their own (this answers Ca's question also) and must take over a cell.

Thanks for the questions.
More later,

Mr. Baker

Inwoo said...

Inwoo Lee
1. Can some mutations be considered a positive effect?
2. Can we manually shuffle DNA codings?
3. What is a frame shift mutation?

ZS said...

1.From the DNA activity, why do we use mRNA instead of tRNA to find the codons?
2. What is trp operons?
3. Cancer is the cell that lost its self-control. When does it happen? Maybe you already answered;;; but I dont' remember;;;

WeNdY said...

Here are my six questions. Three for this week and the three I missed last time.

1] Why doesn't the DNA leave the nucleus instead of making a copy of its code with RNA?

2]Does the cytoplasm decompose DNA like it does MRNA?

3]The book pictures proteins as solid structures. When genes turn into protein in ch 18 they end up as long polypeptide chains. Are these chains modified somewhere into solid shapes or are these only to aid understanding?

1]what decides if the virus is made of rna or dna?

2]How come the most complex viruses affect bacteria?

3]Is a virus's "host Range" written in its dna/rna?

Mr. Baker said...

Good Sunday morning, with my cup of coffee in hand, I will take on a few questions.

Inwoo asked,
"Can some mutations be considered a positive effect?" You bet, it is common for people to think of mutations as negative. In many cases they are, but mutations that improve reproductive success occur and are termed positive.
"Can we manually shuffle DNA codings?" We can in experimental organisms or cell cultures.
"What is a frame shift mutation?" This is a insertion or deletion of DNA bases in multiple other than three such as a two base deletion. This results in the DNA sequence triplet reading frame shifting downstream of the deletion. It typically results in significant changes in the amino acid sequence. This was modeled by the protein synthesis activity in class.
Zena asked,
"From the DNA activity, why do we use mRNA instead of tRNA to find the codons?" This is because in the cell it is the mRNA that is "read".
"What is trp operons?" See the lecture this week.
"Cancer is the cell that lost its self-control. When does it happen?" Again, see lecture this week.
Wendy asked,
"Why doesn't the DNA leave the nucleus instead of making a copy of its code with RNA?" How this evolved, we do not know but the use of mRNA allows multiple copies of a DNA transcript to be produced and avoids the problem of a very long molecule (DNA) having to move about the cell directing the synthesis of protein.
"Does the cytoplasm decompose DNA like it does mRNA?" DNAases do exist in the cell and I would they would degrade DNA if given the chance.
"The book pictures proteins as solid structures. When genes turn into protein in ch 18 they end up as long polypeptide chains. Are these chains modified somewhere into solid shapes or are these only to aid understanding?" If DJ is reading this, correct me if I am wrong. My understanding is that the amino acid chain will spontaneously fold into their secondary structure and some into the tertiary. But there is also some evidence of cellular mechanisms that help and modify proteins so that they reach their tertiary and quarternary structure.
"What decides if the virus is made of rna or dna?" The evolutionary history of the virus.
"How come the most complex viruses affect bacteria?" That is only your perception, do a Google search for HIV and I think you will see a rather complex virus.
"Is a virus's "host Range" written in its dna/rna?" You bet, like all genetic things, the gene determine what it is and does.

Some of you wanted a report on my lab work so here goes. I have reviewed some of the data coming off the sequencer and it looks like I am getting the expected products (alleles). However, I did run into a glitch, I do not have the required size standard and had to use another. Because of this the computer sizing algorithm could not score the data. No worries, this experiment was just to see if the chemistry worked and it does. The most important thing I found out was that the signal was REALLY high (which also makes it hard to score the data). So for future tests, I will make adjustments to reduce the signal.

See you tomorrow I expect that we will be scoring flies. Test Friday.

Mr Baker

Keely said...

Hello all,

Let me start by saying I am so sorry for my late and extra late TQTs. I have nine questions for you. 3 for this week, 3 for last week, and 3 for the week before that. I promise I will have mine on time this week.

1.When DNA is being transcribed why does all the tymine get eventually get converted into uracil?
2.In prokaryotic cells transcription is immediately followed by translation. Why is it in eukaryotic cells there is an in between step (RNA Processing)?
3.In eukaryotic cells why does transcription and RNA Processing occur in the nuclear envelope and translation happens in the cytoplasm?
4.Why is the 3rd base in a codon less influential than the 1st and 2nd base?
5.Viruses can't be destroyed right? If yes, when we get treated for them are we actually just subduing them and they are still "alive" in us? So does that mean every virus we have ever had is still "alive" in us? How can our immune system constantly fight all of them off?
*sorry that was like 4 questions in 1 but they are all related*
6.Also when we are uncontagious how is that possible if we still have the virus?
7.Can you fully destroy bacteris?
*Are diseases mainly bacteris or viruses?*
8.In Ch 18 under the Viral Genomes paragraph it says genomes may consist of double-stranded DNA, single-stranded DNA (How can it be DNA if it's not a double helix? Or how can it be a double helix if it is only a single strand), double-stranded RNA (I thought RNA was only a single-strand. If it's double-stranded does it form a double helix like DNA?), or single-stranded RNA, depending on the specific type of viruse.
9.If viruses aren't alive what are they considered? Are phages alive since it is a bacteria and a virus?

*___* are my side notes.

See you tomorrow,
~Keely

Keely said...

I am glad that your experiment is going well or you are at least getting the results you expected. Good luck on your future experiments.

See you tomorrow,
~Keely

Mr.Sexy said...

Hey Mr. Baker, sorry these questions are a little dated and I haven't keep up with the TQTs but here a my questions. Some are from the early chapters and I started reading just so I can find more questions.

1. Does all homologues have the same gene on every loci of the chromosomes?

2. How long does MRNA transcribes for until it stops?

3. How does the Poly A Polymerase know how many A nucleotides to add onto the end?

4. What happens to the introns after it's been spliced?

5. If genese give you a certain physical characteristic, is ti the same in bacteria cells?

6. Does the "wrapped" viruses just stay inside you, unactive?

7. Whats the use of tryptophan?

8. Does E. Coli just stand for a type of bacteria or is it a named used for all?

9. Could Cancer happen in almost every part of the body, or is there some parts that just can't get it?

10. Could humans evolve like the finches to carry certain types of characteristics necessary to survive or do we just use our brain and make certain tools necessary?

11. Did Darwin's idea get rejected by others?

12. Are plant viruses, just for plants our could they affect mammals?

13.Does every virus have Reverse Transcriptase?

14.Could malfunctions happen where in mRNA they acidentally use Thymine instead of Uracil?

15.During translation, what bond holds together the amino acids in the polypeptides?

I think thats how many i missed. Sorry it was so delayed. I'll try to keep up in the future.

-Uy Hoang

TahiraMadness said...

Hi,
Well I thought better late than never so here are mine.

1) How does recombination work exactly and what does it mean when it asks you how far on the chromosome it is?

2) Why do we need an operon? To stop enzymes? Isn't that bad?

3) If we eat a plant that has a virus will we be infected? If so, how can one tell if their salad has a virus? Does it cry out in pain?

--Tahira