Biology 1A - Lecture 6: Cellular metabolism and biological c

[ForeverHidden626]

i hate you. i hate you. i hate you. my brother loves u but i hate you. he wants to marry you. i hate both of you. have a nice hunny moon suckers!!!!!!!!!!!!!!!!!!!!!!1

[Denkverbrecher]

Cool, i have cut a fly in half with my scissors! What a dumb ass of a fly sitting on my shooldesk! But she is fine! She only cant fly anymore.

Now we can learn togheter! :)

[farzanatasneem]

A very large number of genes do not encode proteins. Instead, their products play important regulatory functions. The most recent among this class are genes that encode small RNA molecules, so-called microRNAs (miRNAs). miRNAs, unlike other RNAs, do not encode proteins but instead inhibit gene expression..Silencing of gene expression by miRNA is preserved in all living forms from plants to humans and therefore must be a fundamental mechanism of gene regulation.

[farzanatasneem]

By current estimates, there are approximately 1000 genes in humans that encode miRNAs. Transcription of miRNA genes produces primary microRNA transcript (pri-miRNA), which is processed within the nucleus to form another structure, called pre-miRNA.With the help of specific transporter proteins, pre-miRNA is exported to the cytoplasm. Additional "cutting" by an enzyme, appropriately called Dicer, generates mature miRNAs that are about 21 to 30 nucleotides in length.(hence the name "micro").

[farzanatasneem]

Hi

I am discussing Thermodynamics with someone on youtube.

Can I take a part of your clips in between my statements for further elaboration?

[IntelligentsiaUS]

@TheMarlon2012- I'm self-studying AP biology,and I definitely agree. These videos are so helpful!

[safewayselect]

Who is this guy? shes hot!

[farzanatasneem]

@safewayselect

That's a wrong way of looking at the things.

[TheMarlon2012]

I'm in high school taking AP Biology and this video really help to understand better about this stuff. Thumbs up. :)

[ForeverHidden626]

@TheMarlon2012 I'm in highschool & nobody give's a shit fool. shut up!

[seanmPWH]

At 18:30 the idea that biological systems don't violate the 2nd law because ultimately there will be universal equilibrium misses the point. Why sweep the local entropy violations under the universal rug? It's exactly the need for biology to break entropy that's raises interest. Why dodge the issue?

[chroniclerofthe70s]

@seanmPWH What do you mean break entropy? The 2nd law of thermodynamics means any natural process the total entropy of the universe increases. The 2nd law of thermodynamics isn't violated by cellular biochemical reactions. The cell isn't a closed system.

[farzanatasneem]

@chroniclerofthe70s

The second law of thermodynamics when applied to open system too need a machine to convert the energy.

If we are talking about biological system , then cell has that machine in the form of its organelle which are programmed to change the type of energy.

Even food energy is transferred in body after splitting it , and then absorption followed by transport and then deposition or utilisation.

During all these processes the energy is consumed which increases the overall entropy

[chroniclerofthe70s]

@farzanatasneem Nonsense. Organelles are not programmed. Entropy is a state of disorder and can be quantized in relation to energy. Energy is released when biomolecules are assembled in the form of free energy.

Secondly, when more orderly structures are assembled, the amino acids and salts which are held in highly ordered states in the form of water caged molecules go from lower entropy states to an increased state of entropy.

I suggest you learn more advanced chemistry.

[farzanatasneem]

@chroniclerofthe70s

"I suggest you learn more advanced chemistry"

I suggest you learn more advanced cellular biology and the beginning of this video is enough for you to understand how many chemical reactions are going on in a single cell.

These are all organised and compartmentalised so as not to influence each other in a way to give wrong outcome.

Ordered and organised are two different entities

[chroniclerofthe70s]

@farzanatasneem I have studied graduate level Biochemistry and Molecular Cell Biology. Your simplistic non technical statements suggests you have a novice understanding of these disciplines.

Glycolysis occurs in the cytosol, fool.

Protein synthesis occurs on ribosomes on the surface of RER. The golgi apparatus is continuous where sugar moeity modifications occur. You're no one to give advice to me , I've taught advanced Genetics and Molecular Biology.

[farzanatasneem]

@chroniclerofthe70s

The way you speak does not designate that you belong to culture called "Educated"

And you are yourself declaring the correctness of my statements.

Protein synthesis starts in nucleus as the first step when DNA unwinds to create mRNA which is formed in nucleus and then it(mRNA) is transferred to cytosol and rest of the protein synthesis takes place in ribosomes.

But there is role for miRNA too.

Isn't this all compartmentalised for a newcomer ??

[chroniclerofthe70s]

@farzanatasneem  Correction of your statements? Why embarrass yourself any further to other YT readers with your comments.

Protein synthesis takes place only in the cytoplasm.

First, histones must be dissociated from DNA in chromatin as part of eukaryotic DNA replication,

synthesis, and transcription.

Secondly, mRNA is processed by removal of introns and strand end modifications before it is

transferred into the cytoplasm.

Prokaryotic cells do not contain organelles.

[MsAgnosticatheist]

@chroniclerofthe70s What are some good books, videos, etc. sources you recommend for layman?

[chroniclerofthe70s]

@MsAgnosticatheist I suggest a college freshman level Biology textbook which are generally comprehensive and often include an introductory chapter(s) on general chemical structures and principles. I suggest supplementing with semi-technical publications such as Scientific

American, Discover, or Popular Science. Good luck.

[NorthForkFisherman]

@MsAgnosticatheist "Molecular Biology Made Simple and Fun, 3rd ed" By Lewis is a good one. And of course, this string of videos. They use the same book (Campbell, but slightly different ed) at JCCC, here in Kansas.

[SharathCK]

Undergrad teachers at Berkeley are really good in comparison to other colleges (*cough* MIT *cough*). Makes me wish I applied here.