WheatLom

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Hi I wanted to make this thread to see if people had content questions for the DAT. I usually learn best from teaching and was hoping people could ask me questions they have. That way, if I don't know the answer right away I can study it and reply, or further reinforce my knowledge!

Shoot away at me! If I truly can't help, I will tell you. Cause that could be damaging for both of us.

OR QUIZ ME!!

Once I reply, can you edit your original post and put answered, so I don't miss any.

Ill be on here all day, and tomorrow and the 8th. 9th is my DAT but Ill help out after lol. Replies within 20-25 minutes, unless I am looking up more information to connect the ideas for people.
 
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Hard Work Pays Off

Leo the Lion says Ger
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oooh cool, can we ask general questions? like what in the world are the carboxylic acid derivative reactions and how can we remember them
 
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WheatLom

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Yea, honestly ask away, if one person has a question another likely does.
oooh cool, can we ask general questions? like what in the world are the carboxylic acid derivative reactions and how can we remember them

Yep, If one person has a question another is likely to have it so, go for it! Ill post your answer in a few minutes.
 

asdf99

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Are the archenteron and the coelem the same thing? And which tissue layer lines these structures?


Lovely idea man, when do you write?
 
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WheatLom

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The carboxylic acid derivatives are R- COZ groups. The C=O is a carbonyl,

Z group can be the following. (It can not be an R group as that would be a Ketone.)

1)chloride - acid chloride
2)OCOR - anhydride
3)OR - ester
4) -OH carboxylic acid
5) NH2 (NRH or NR2) will be an amide.

To remember the reactions, I feel there is no easy way, but there are clue you can use.

Oxidation versus Reduction
- Looking through my Organic book, you rarely if ever see oxidation of carboxylic acids, cause they are already oxidized. usually you will see reduction. Therefore it is useful to know what product of reduction can be.


Type of reaction

-These derivatives usually will go through substitution. Why? Because I said so!!!! Joking. They substitute because a nucleophile attacks the carbonyl Carbon, which then causes the existing Z group to leave as a leaving group.
-It is good to know the reactivity of the derivatives. I listed the derivatives in most reactive to less reactive. ****3 and 4 are similar in reactivity*** You can go from a more reactive derivative to a less reactive one, not the other way around, unless you use some other means.


Let me know if you want me to add to it, I went to my OCHEM book and summarized some key points.
 
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WheatLom

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Are the archenteron and the coelem the same thing? And which tissue layer lines these structures?


Lovely idea man, when do you write?
I feel like this is tricky. The Archenteron is what forms when you are developing, it is the primitive gut cavity. The coelom refers to the developed cavity and is surrounded by other tissues. This throws me off too, but coelom is more for developed organisms, while archenteron is for developing organisms. The Archenteron, can form the coelom if that species is a coelomate. Some organisms are pseudocoelomates (gut cavity, but no surrounding tissue. Think of it suspending in the body.


Left out the second part.

The Archenteron develops into the mesoderm and endoderm, therefore the coelom is likely surrounded by the same tissue layers. Obviously some nervous tissue from the ectoderm will be there, but the meso and endoderm are more abundant.
 
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asdf99

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I feel like this is tricky. The Archenteron is what forms when you are developing, it is the primitive gut cavity. The coelom refers to the developed cavity and is surrounded by other tissues. This throws me off too, but coelom is more for developed organisms, while archenteron is for developing organisms. The Archenteron, can form the coelom if that species is a coelomate. Some organisms are pseudocoelomates (gut cavity, but no surrounding tissue. Think of it suspending in the body.


Left out the second part.

The Archenteron develops into the mesoderm and endoderm, therefore the coelom is likely surrounded by the same tissue layers. Obviously some nervous tissue from the ectoderm will be there, but the meso and endoderm are more abundant.

Appreciate it man, that first paragraph really brought things together. Thanks!
 

Samin23

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What are the avascular plants? In some places, I see that mosses and ferns are both avascular, and in other places I see that only ferns are avascular :bang:
 

asdf99

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What are the avascular plants? In some places, I see that mosses and ferns are both avascular, and in other places I see that only ferns are avascular :bang:
My understanding was that mosses were avascular, and that ferns were vascular?

Not really sure though, plants aren't my forte. Kind of just winging/yoloing that section lol. Hopefully wheatcom can chime in
 
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WheatLom

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What are the avascular plants? In some places, I see that mosses and ferns are both avascular, and in other places I see that only ferns are avascular :bang:

PLANTS!!!!! GOTTA LOVE THEM, hate to study them.

There are 4 groups of Plants, I will put them from oldest to newest.

Primative
avascular
Bryophytes -mosses
Vascular
Lycophytes - ferns
Gymnosperms - conifers, naked seeds
Angiosperms - flowering plants, seeds that are enclosed.

Less primitive

Even if you did not know much about plants you can think of this with a little bit of logic.

Mosses are avascular, if you think about it when have you seen a moss that is more than a foot tall (if they even get that tall). To be able to grow big you need something to transport nutrients and water. Mosses lack xylem and phloem which means, all cells need to be in almost direct contact with the environment to get nutrients and water.

Ferns are vascular they do have xylem and phloem. Which allows them to grow taller and bigger. They are able to transport nutrients so their growth is not directly related how close they are to their nutrients, they can transport them from distances.

Hope this helps.
 
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fayevalentine

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Do you have any tips for remembering things like epidermis layers, cells of the different layers, and so on? Merkel cells, all that junk?
 
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WheatLom

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Do you have any tips for remembering things like epidermis layers, cells of the different layers, and so on? Merkel cells, all that junk?
I haven't looked into the skin that much.

I would go with more a logical sense, look at the roots and stems of words that can help give you meaning to the words. like Melanocyte, most likely has something to do with melanin and building.

Outer to inner part of skin.

The epidermis is mostly dead skin cell and avascular. This layer is a protective layer. There are some living cells closer to the dermis, that produce keratin and melanin.

The dermis is where all the nerves and blood vessels are. It is mostly living cells. From my understanding the cells of the dermis shed into the epidermis then off the body. If you get a cut and bleed that means you've reached the dermis. Hair follicles are also here. It would make sense as there is blood and living cells. Glands would be here.


The subcutaneous layer (not part of skin) is fatty and it is a shock absorbing type layer


It is good to know skin is part of the non-specific immunity and is acidic.

Certain cells. LT and MT could help. Langerhan cells are related to T-cells. Merkal cells to Touch.

I hope this helps, skin was not a big thing to study for me, but I did review it to type this post out.

Ill add some stuff as I learn more.

So I reread feralis' notes. Most of the skin information is pretty common sense, Like sweat leaves here, thermoregulation, immune protection. There may be more, but Feralis covers mostly all I said.
 
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LuckBloodandSweat

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Do you have any tips for remembering things like epidermis layers, cells of the different layers, and so on? Merkel cells, all that junk?
Here's a weird thing I did, (CLGSB) = Coral (Corneum) League (Lucidum) Gaming (Granulosum) Sponge (spinosum) Bob (basale) xD!! I don't know how helpful that is for you though!
 
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LuckBloodandSweat

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Hi I wanted to make this thread to see if people had content questions for the DAT. I usually learn best from teaching and was hoping people could ask me questions they have. That way, if I don't know the answer right away I can study it and reply, or further reinforce my knowledge!

Shoot away at me! If I truly can't help, I will tell you. Cause that could be damaging for both of us.

Once I reply, can you edit your original post and put answered, so I don't miss any.

Ill be on here all day, and tomorrow and the 8th. 9th is my DAT but Ill help out after lol. Replies within 20-25 minutes, unless I am looking up more information to connect the ideas for people.
You are a noble man :)! GOOD LUCK DUDE YOUVE GOT DISSSSSSSSSS :D
 

LuckBloodandSweat

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Thank you!! You got any questions?! or want to quiz me. Ill tell you if I had to look it up or not too haha.
Lol i've been done with the DAT for over a week bro! xDD. Not sure how wise it would be to retake my 23 o_O. Although if I'm really that bored.... NO NOT A THIRD TIME >xD
 

fayevalentine

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I haven't looked into the skin that much.

I would go with more a logical sense, look at the roots and stems of words that can help give you meaning to the words. like Melanocyte, most likely has something to do with melanin and building.

Outer to inner part of skin.

The epidermis is mostly dead skin cell and avascular. This layer is a protective layer. There are some living cells closer to the dermis, that produce keratin and melanin.

The dermis is where all the nerves and blood vessels are. It is mostly living cells. From my understanding the cells of the dermis shed into the epidermis then off the body. If you get a cut and bleed that means you've reached the dermis. Hair follicles are also here. It would make sense as there is blood and living cells. Glands would be here.


The subcutaneous layer (not part of skin) is fatty and it is a shock absorbing type layer


It is good to know skin is part of the non-specific immunity and is acidic.

Certain cells. LT and MT could help. Langerhan cells are related to T-cells. Merkal cells to Touch.

I hope this helps, skin was not a big thing to study for me, but I did review it to type this post out.

Ill add some stuff as I learn more.

So I reread feralis' notes. Most of the skin information is pretty common sense, Like sweat leaves here, thermoregulation, immune protection. There may be more, but Feralis covers mostly all I said.
Thank you! :)
 

Hard Work Pays Off

Leo the Lion says Ger
Jun 17, 2016
48
47
I get the claisen condensation and aldol condensation stuff mixed up because mostly they both use NaOH, so is the only difference that the claisen ones have an ester and the aldols are ketones or aldehydes? thanks for your help!
-and good luck on your exam tomorrow I'm rooting for you
 
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Dec 31, 2015
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Claisen requires NaOEt, aldol uses NaOH.

Claisen needs NaOEt, because OEt- acts as a base to take the hydrogen and form the enolate to do the claisen condensation. However, NaOEt also acts as a nucleophile where it will kick the LG group off. However, since we are using NaOEt then nothing changes because the base is NaOEt and the LG is also OEt. So for claisen condensation we use the LG as a base in a sense which is always NaOEt.
 
Dec 31, 2015
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I have a question. For claisen condenstation step #2 requires H30+. If all carboxylic acid derivatives turn into carboxylic acids with H30+ ,then how come the ester stays the same?
So why does the ester stay the same, and what's the point of the H30+ step? (I know the answer, just quizzing you)
 
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WheatLom

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I have a question. For claisen condenstation step #2 requires H30+. If all carboxylic acid derivatives turn into carboxylic acids with H30+ ,then how come the ester stays the same?
So why does the ester stay the same, and what's the point of the H30+ step? (I know the answer, just quizzing you)

Well, since the reaction is under basic conditions the alpha hydrogens between the two carbonyls are still highly acidic. So the free roaming bases would still deprotonate it, and it would be resonance stabilized cause there is a lot of electrons in the area. The acid would just neutralize the base, as well as reprotante the deprotonated product.


I will say I had to look this up as the answer is a little more in depth than you would think. Soon as acid is mention I just think ADD a H or water. I was prettier close before I looked it up, but I still was a little iffy on it!! Thanks for the quiz DAT is 16 hours!!!!!
 
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WheatLom

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I get the claisen condensation and aldol condensation stuff mixed up because mostly they both use NaOH, so is the only difference that the claisen ones have an ester and the aldols are ketones or aldehydes? thanks for your help!
-and good luck on your exam tomorrow I'm rooting for you
Thank you man!! appreciate it a lot. I will be submitting my application on wednesday. I will recheck my information on there and shoot it through. Hopefully I can add a few higher up schools cause I am mostly applying to lower schools to increase my chances. BUT ANY SCHOOL I get into will be my number one school and my top school. Opportunity is the most important.
 
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WheatLom

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I have a question. For claisen condenstation step #2 requires H30+. If all carboxylic acid derivatives turn into carboxylic acids with H30+ ,then how come the ester stays the same?
So why does the ester stay the same, and what's the point of the H30+ step? (I know the answer, just quizzing you)

Im going to take a jab at the ester part. I believe the ester is pretty stable and its reactivity is similar to a carboxylic acid. It could easily have a O+1 and kick the carbonyl electrons onto the other O.

Why mess with a structure that has some resonance.
 
Dec 31, 2015
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Yeas, also esters typically turn into carboxylic acids with hydronium, but for claisen condensations it's very very dilute so it doesn't react with the ester, but just enough for reprotonation.
 
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WheatLom

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Yeas, also esters typically turn into carboxylic acids with hydronium, but for claisen condensations it's very very dilute so it doesn't react with the ester, but just enough for reprotonation.

The power of LOGIC hahaha. Ill see you all tomorrow. I may post a break down and I may not tomorrow. But I think I will as long as I am proud of my scores. I know Im leaving it all on the computer tomorrow.
 
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Charles_Darwin

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The power of LOGIC hahaha. Ill see you all tomorrow. I may post a break down and I may not tomorrow. But I think I will as long as I am proud of my scores. I know Im leaving it all on the computer tomorrow.
Good luck! Post a break down no matter what - I'm sure you'll kill it
 
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WheatLom

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Good luck! Post a break down no matter what - I'm sure you'll kill it
Thank you. I appreciate it. EATing a lot of carbs and fruit to get my sugars up for tomorrow. Want to be all fueled. up.


ANYONE CAN STILL POST QUESTIONS. I KNOW THERE IS A DESTROYER THREAD, BUT FOR THOSE WHO DONT HAVE DESTROYER THEN THERE ISNT MUCH.
 

Charles_Darwin

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Thank you. I appreciate it. EATing a lot of carbs and fruit to get my sugars up for tomorrow. Want to be all fueled. up.


ANYONE CAN STILL POST QUESTIONS. I KNOW THERE IS A DESTROYER THREAD, BUT FOR THOSE WHO DONT HAVE DESTROYER THEN THERE ISNT MUCH.
spinach and blueberries if you've got time for a grocery store run tomorrow! antioxidants = :prof:
 
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I get dieckman and claisen confused?!! They both use NaOEt.. How do I know which to use!????



Claisen requires NaOEt, aldol uses NaOH.

Claisen needs NaOEt, because OEt- acts as a base to take the hydrogen and form the enolate to do the claisen condensation. However, NaOEt also acts as a nucleophile where it will kick the LG group off. However, since we are using NaOEt then nothing changes because the base is NaOEt and the LG is also OEt. So for claisen condensation we use the LG as a base in a sense which is always NaOEt.
get
 
Jun 25, 2016
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The carboxylic acid derivatives are R- COZ groups. The C=O is a carbonyl,

Z group can be the following. (It can not be an R group as that would be a Ketone.)

1)chloride - acid chloride
2)OCOR - anhydride
3)OR - ester
4) -OH carboxylic acid
5) NH2 (NRH or NR2) will be an amide.

To remember the reactions, I feel there is no easy way, but there are clue you can use.

Oxidation versus Reduction
- Looking through my Organic book, you rarely if ever see oxidation of carboxylic acids, cause they are already oxidized. usually you will see reduction. Therefore it is useful to know what product of reduction can be.


Type of reaction

-These derivatives usually will go through substitution. Why? Because I said so!!!! Joking. They substitute because a nucleophile attacks the carbonyl Carbon, which then causes the existing Z group to leave as a leaving group.
-It is good to know the reactivity of the derivatives. I listed the derivatives in most reactive to less reactive. ****3 and 4 are similar in reactivity*** You can go from a more reactive derivative to a less reactive one, not the other way around, unless you use some other means.


Let me know if you want me to add to it, I went to my OCHEM book and summarized some key points.

I don't know names of any reactions like I know how to do em but like I would never know somethinn is an electrophillic addition or a "nuclelophilic substitution" or a "reduction" like I just solve the resection no idea of the name.
Is there a way of knowing without memorizing what each is like if I gained this and this it's a blabla if I got this than its a blabla u know? Or any easy way of knowing cuz they might just say does this act as a base or is this addition and I gots no idea!!!
 

LuckBloodandSweat

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Well Electrophilic Addition has an electrophile (has + charge) and Nucleophiles have a negative charge. I'm not amazing at explaining orgo but that's the simplest way I can put it if you want to know the basic concept.
 

orgoman22

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I get the claisen condensation and aldol condensation stuff mixed up because mostly they both use NaOH, so is the only difference that the claisen ones have an ester and the aldols are ketones or aldehydes? thanks for your help!
-and good luck on your exam tomorrow I'm rooting for you
The Aldol is employed when an aldehyde or ketone with an ALPHA hydrogen is treated with dilute acid or base...or even LDA. The Claisen is employed when an ESTER containing an alpha hydrogen is treated with a base such as sodium ethoxide or sodium methoxide.....NEVER NEVER hydroxide.

Hope this helps.

Dr. Romano
 

fit2

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Well Electrophilic Addition has an electrophile (has + charge) and Nucleophiles have a negative charge. I'm not amazing at explaining orgo but that's the simplest way I can put it if you want to know the basic concept.
This confuses me too though and just thinking about it doesn't seem to always work. For example I got a question wrong that said: What kind of reaction is the formation of an acetal? I think response is nucleophilic substitution....why? Anyone who could explain the reaction categorizations that would indeed be helpful :p
 
Jun 25, 2016
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The Aldol is employed when an aldehyde or ketone with an ALPHA hydrogen is treated with dilute acid or base...or even LDA. The Claisen is employed when an ESTER containing an alpha hydrogen is treated with a base such as sodium ethoxide or sodium methoxide.....NEVER NEVER hydroxide.

Hope this helps.

Dr. Romano
What about Claisen vs. Dieckman?????