Question

The cellular component responsible for transmission of traits and control of cell function was long assumed to be proteins. Discuss the characteristics of proteins and DNA that made protein initially seem the more likely candidate, and outline the seminal studies that implicated DNA as the molecule of heredity and determination of trait.

Answer 1

@InYourHead

Answer 2

do you know their structures? of DNA and protein

Answer 3

like helical structure?

Answer 4

@Ammarah No, the chemical make-up.

Answer 5

adenine thymine or phosphate groups?

Answer 6

everything

Answer 7

deoxyribose sugar
phosphate backbone
nitrogenous bases

Answer 8

@Ammarah Do you know how many nucleic acids are used in DNA? How many different proteins there is?

Answer 9

nope...

Answer 10

I don't like how the directions are worded. Let me rephrase them:

"Once upon a time, everyone thought that proteins were the most important part of all living things.
They thought that everything about life began with proteins.
But NOW, we know that DNA is what determines traits and characteristics of living things."

So, we have to talk about two things:

1. The reason for why people used to think that proteins were responsible for everything about life. (Even though it's not true, it still was a good guess.)

2. The reason for why we know, now, that DNA is more responsible for life than proteins.

Answer 11

So you know that proteins are made from DNA, yeah?

You remember "transcription" and "translation"?


We're human. And humans are made of protein.

Most of the human body is water.
But whatever isn't water is MOSTLY protein.

Proteins are like the building blocks that make us who we are.

There are many different kinds of proteins in the human body. More than 100,000.

Our hair, eyes, skin, muscles, and bones are all different from one another.
They're all made of different kinds of proteins.

SO....Because proteins are all so different, people used to think that proteins were responsible for all of life. I mean...wouldn't that make sense?

Remember, proteins are the building blocks that make up humans, and all life.

You and I both look different, because we're both made of different kinds of proteins, in different combinations.

-----------

Well, people used to think that proteins were the beginning of life.

But NOOOWWW...we know how proteins are made.

Proteins are made from DNA. Remember?

-----------

So, again, we have to talk about two things:

1. The reason for why people used to think that proteins were responsible for everything about life. (Even though it's not true, it still was a good guess.)

2. The reason for why we know, now, that DNA is more responsible for life than proteins.


I've already explained #1.

Now, can you explain #2?
Describe how protein is made from DNA. As best as you can.

Answer 12

Protein first goes through transcription and then rna comes into place creating the amino acids of protein These are then turned into polypeptides through translation.

Answer 13

nope
Step 1
DNA strand is used as a template to make messenger RNA / mRNA strand
this step is called transcription

Step 2
mRNA leaves the nucleus through nuclear pores and goes to either rough endoplasmic reticulum ribosomes or cytoplasmic ribosomes
Now Step 2 starts once mRNA binds to small subunit of ribosome and then large subunit binds to smaller one -
this step has more steps in it
- transfer RNA comes with anti-codons of mRNA codons
- it (tRNA/transfer RNA) brings amino acid corresponding to codon (for example if codon on mRNA is AUG, then tRNA will have anticodon UAC and amino acid methionine)
-once tRNA matches its anticodon with codons on mRNA and finds its corresponding codon - it leaves the amino acid to bind to the growing polypeptide

this is whole step in short pretty much and this step is called translation

at the end we get a polypeptide that then is to be transported to Golgi complex for modification and packaging

Answer 14

Okay, you are missing the core reason why proteins were considered to be the unit of heredity. There is a lot of variation in lifeforms and between lifeforms. We knew there was 20 or more proteins found and essential to all lifeforms, while there was only 4 (5 if you count uracil) base pairs. It was thought that the variation in life could not be the result on only 4 different chemicals.

You must keep in mind that at the time we did not understand how proteins were made.

You need to look up early transformation experiments and the importance of the fact that S is in many amino acids but not in any nucleic acids.

Answer 15

@mrdoldum " there was 20 or more proteins found and essential to all lifeforms " do you mean amino acids?

Answer 16

just simplify the answer for me guys....

Answer 17

@Somy Sorry, yes I meant amino acids that make up the proteins.

Answer 18

@Ammarah We are not here to simply give you answers. That is against policy.

Answer 19

omg i want the answers so i can have an idea of what im learning...

Answer 20

I gave you enough info that if you look up things online you can figure it out. I'm not going to give you a simplified answer for a question that asks for just that.

Answer 21

ok please help me with this one i can just google it but i want some advice from u guys

Answer 22

Telomeres, or the ends of linear chromosomes, have special structure and function, even though they are

non-coding. Describe their structure and function.

Answer 23

If you post what confuses you I will help you understand it.

Answer 24

@Ammarah Once again, if I cannot help without you making an attempt. What do you think a telomere is and what its function is?

Answer 25

i dont know what it is please explain it to me

Answer 26

@Ammarah No. I already said I am not going to do so. If I tell you what they are I will be giving you the answer.

Answer 27

i have a test and im studying for it

Answer 28

@Ammarah You have to had this material presented to you at some point if you are going to have test about it. You are clearly on the internet. You can do a quick search, even on wikipedia, and read what a telomere is and what it does. If you do so, and come back here and let me know what your read, what you think it means, and what is confusing, I will work with you and get you to the correct answer.

Answer 29

wow thanks

Answer 30

@ammarah If you don't want to put any more effort in than having some one simply give you the answers, then I am not going to help. I am in the very last semester of my PhD in molecular biology and I see kids with this attitude all the time, usually by the end of the semester they are or a very close to failing the course.

Maybe some one else will do you the disservice of simply providing the answers, but I will not.

Answer 31

u know what i totall agree with you. Thankyou i was getting very lazy and just didnt want to look it up. Pleasee just help me become a better student in biology. Will u help me prepare for my upcoming ap test in may"?

Answer 32

i need a good teacher like you to give me strong advice and tips to get a top score on the ap exam and the class

Answer 33

@mrdoldum true said there! I'm a first year med student and even some of my classmates are like that - no studying, no questioning and no researching......no idea how are they gonna become a doctor without putting effort and working hard... Good luck in finishing PhD!

Answer 34

@Ammarah I am more than happy to help you understand material, so long as you make an effort. This does not mean I expect you to have near complete understanding before asking a question, just that you identify what is confusing to you and, if possible, why.

Example, instead of posting "I don't understand genetics" or "What is a telomere" give me what you know and think like, "I don't understand how we find out the inheritance pattern of a gene" or "I know telomeres are at the ends of chromosomes, but I don't understand why they matter and how they relate to an organisms lifespan."

Feel free to send me a PM on here. You don't have to wait for me to respond to posts. I'll even read emails sent to a-r-t-h-r-o-t-o-k*@*mail-.-com \(\bf remove all "-" and "*"\)

@Somy Thanks, and good luck in med school.

Answer 35

@mrdoldum Thanks!!