Questions and Answers

VEGANGELICA · 10-14-2009, 12:27 PM

Quote:

Originally Posted by kayleigh.

i always wonder how humans actually work. i do know how they work. but i want to know what causes the chemical reactions, and how it all just happens? followin' me? its kind of hard to explain

Hi kayleigh,

Toretorden gave a good description of how we are, each of us, a community of cells that grow as they do by following the instructions that are their DNA molecules, with the environment having some impact on how the instructions are used.

My interest in life and how it works inspired me to study biology. You get a feeling for "how humans (living organisms) actually work" by studying general biology, anatomy, cell biology, and biochemistry, and then chemistry and physics. Usually students start with biology, then take physics, then chemistry, but may not get to really feel or see how the information combines to give a deeper understanding of how life works until they get to biochemistry (and enzymology). I feel biochemistry, the chemistry of life, really shows best on a fundamental level how our bodies use food energy to keep themselves and their processes going.

I get really excited about the topic of how we work! For example, do you recall that inside your cells are small oval structures, the mitochondria, which allow your cells to transfer some of the energy of food into the energy of a type of molecule (ATP) that cells use to drive cell processes? This process requires oxygen, and is essentially like a controlled fire. When you mix wood, oxygen, and a spark, you get fire. In us, the food that we eat is what gets "burned," but the body doesn't release all the energy as heat. Instead, a lot of the energy is bound up as chemical energy...the energy that is in the bonds holding one atom to another.

Also, something else fascinating is that our cells have mitochondria because long ago one of our (free-living) ancestor cells engulfed (but did not digest) a free-living bacterium, according to the theory of endosymbiosis (which is accepted as fact because of all the evidence).

So, we humans (and other animals) are like a slow, controlled burning fire...and we are partly bacterial in origin! Weird and wonderful.

I love the way we living beings are like one gigantic organism that stretches through time, like a growing vine, where only the tips of the branches remain alive. Each of us feels like a separate being, but in fact is actually just the present-time manifestation of this giant organism (life) that began billions of years ago.

Quote:

Originally Posted by boo boo

I'm not sure why so many people are worried about what is going to happen to the universe in tens of billions of years.

I don't think anyone here is gonna be around that long, except Urban, his hatred for everything is so powerful that it has made him immortal.

I don't worry about what will happen to the universe far in the future...but I definitely think about it. Learning about what science predicts gives me a sense of perspective...and a sense of sadness for those organisms who will probably evolve on other planets far in the future and, due to the universe's expansion, will not be able to see and learn as much about the universe and its origins as humans can now.

dollarsandcents · 10-14-2009, 12:34 PM

Another biology student, yey! Some good classic analogies used above. Can't beat a few good analogies to get across a potentially complicated concept. I think the key to a good understanding of something complex is to be able to make it understandable to a wider audience. Guess that's why people like Dawkins and Hawkings are so successful as popular (to an extent) fiction writers.

FETCHER. · 10-14-2009, 12:56 PM

Quote:

Originally Posted by toretorden

That's a hard question because it's extremely general and could touch on a wide variety of subjects and if you wanna get into the intricacies of it all, of course then we don't know everything yet and you could devote years of study to something like that. It's still possible to summarize the very basics. You might know them, but I could try and sum them up

Humans are made up of many cells. Each cell came from a splitting parent cell, so cells are made by cells. The inside of the cells are somewhat closed to the outside environment by a membrane and they have a core where you find DNA. Now we've split humans up into three parts, humans - cell - DNA.

DNA are very long molecules made up of 4 repeating parts and you can imagine it almost as a long double strand of letters (A, C, G, T).

AGCTTCGTC
GATCCTACT

These letters are complementary (a C on one side means a T on the other) and can be read like a code. The DNA codes for proteins. The chemical processes in your body are catalyzed by enzymes which are proteins whose blueprints are found in the DNA.

Not all the DNA is used in all cells. Different cells use different genes to produce different proteins that do different jobs, f.ex facilitate different chemical reactions. The reading and translation from DNA to proteins is also done by proteins.

This is pretty inaccurate and simplified, but to summarize : Humans are made from a blueprint in their cells called DNA. The DNA codes for proteins which are large molecules that do jobs like facilitating chemical reactions in your body. Different cells produce different proteins which is why they are different. All the cells together (liver cells, muscle cells, skin cells) make up a human.

The first cell containing your DNA and which first started splitting into the multitude of cells that make up you came from your parents and theirs came from their ancestors and so it goes backwards in time until the start of your lineage thousands of millions of years ago.

I've tried to keep this simple on purpose and while I don't think it answers your question, perhaps it'll help you formulate a new one.

i understand the structure of DNA etc, as when i dont Biology, it was the sections which included humans in which i was most interested in. as i wanted to know how and why everything in a human works, but what starts it all off? is the mother/baby relationship basically like jumpstarting a car?
anyways thanks Tore, that decribed some stuff i actually found confusing and difficult at school

.

Quote:

Originally Posted by VEGANGELICA

Hi kayleigh,

Toretorden gave a good description of how we are, each of us, a community of cells that grow as they do by following the instructions that are their DNA molecules, with the environment having some impact on how the instructions are used.

My interest in life and how it works inspired me to study biology. You get a feeling for "how humans (living organisms) actually work" by studying general biology, anatomy, cell biology, and biochemistry, and then chemistry and physics. Usually students start with biology, then take physics, then chemistry, but may not get to really feel or see how the information combines to give a deeper understanding of how life works until they get to biochemistry (and enzymology). I feel biochemistry, the chemistry of life, really shows best on a fundamental level how our bodies use food energy to keep themselves and their processes going.

I get really excited about the topic of how we work! For example, do you recall that inside your cells are small oval structures, the mitochondria, which allow your cells to transfer some of the energy of food into the energy of a type of molecule (ATP) that cells use to drive cell processes? This process requires oxygen, and is essentially like a controlled fire. When you mix wood, oxygen, and a spark, you get fire. In us, the food that we eat is what gets "burned," but the body doesn't release all the energy as heat. Instead, a lot of the energy is bound up as chemical energy...the energy that is in the bonds holding one atom to another.

Also, something else fascinating is that our cells have mitochondria because long ago one of our (free-living) ancestor cells engulfed (but did not digest) a free-living bacterium, according to the theory of endosymbiosis (which is accepted as fact because of all the evidence).

So, we humans (and other animals) are like a slow, controlled burning fire...and we are partly bacterial in origin! Weird and wonderful.

I love the way we living beings are like one gigantic organism that stretches through time, like a growing vine, where only the tips of the branches remain alive. Each of us feels like a separate being, but in fact is actually just the present-time manifestation of this giant organism (life) that began billions of years ago.

I don't worry about what will happen to the universe far in the future...but I definitely think about it. Learning about what science predicts gives me a sense of perspective...and a sense of sadness for those organisms who will probably evolve on other planets far in the future and, due to the universe's expansion, will not be able to see and learn as much about the universe and its origins as humans can now.

i can relate to that in bold! thats why i want to study Biology

.
the italics i found was a good metaphor to describe the way in which the body works, thanks.
i found the rest helpful also, thanks Veg!

boo boo · 10-14-2009, 09:02 AM

Well, if you believe in an etternal afterlife you might possibly be around for that long, but I think any kind of afterlife would exist on a different plain from the universe as we know it.

boo boo · 10-15-2009, 12:28 AM

SteW · 10-15-2009, 10:02 AM

It could explain things like deja vu, psychics etc.

Guybrush · 01-22-2010, 05:45 AM

I have another question for someone who knows astronomy. Not someone who thinks they know astronomy, because then I might as well answer my own questions.

Anyways, what's a quasar? The way I understand it is that it's a particularly big black hole at the center of a galaxy - but I'm guessing black holes at galaxy centers is a common feature. Quasars are particularly big? There's some kind of radiation streaming out from the "top and bottom" of it? Why does it do that? Shouldn't all galaxies develop quasars as their black holes swallow more and more mass?

I could look it up I guess, but I figured "why not milk this old thread a little more?" .. So, anyone who knows this stuff?

Freebase Dali · 01-22-2010, 06:12 PM

^

10-14-2009, 12:34 PM	#2 (permalink)
dollarsandcents more tea vicar? Join Date: Aug 2009 Location: England Posts: 193	Another biology student, yey! Some good classic analogies used above. Can't beat a few good analogies to get across a potentially complicated concept. I think the key to a good understanding of something complex is to be able to make it understandable to a wider audience. Guess that's why people like Dawkins and Hawkings are so successful as popular (to an extent) fiction writers. __________________ My Blog: You And Whose Army?

10-15-2009, 10:02 AM	#6 (permalink)
SteW Groupie Join Date: Sep 2009 Location: Cardiff, Wales Posts: 5	It could explain things like deja vu, psychics etc. Last edited by SteW; 10-15-2009 at 10:03 AM. Reason: grammar

01-22-2010, 05:45 AM	#7 (permalink)
Guybrush Juicious Maximus III Join Date: Nov 2008 Location: Scabb Island Posts: 6,525	I have another question for someone who knows astronomy. Not someone who thinks they know astronomy, because then I might as well answer my own questions. Anyways, what's a quasar? The way I understand it is that it's a particularly big black hole at the center of a galaxy - but I'm guessing black holes at galaxy centers is a common feature. Quasars are particularly big? There's some kind of radiation streaming out from the "top and bottom" of it? Why does it do that? Shouldn't all galaxies develop quasars as their black holes swallow more and more mass? I could look it up I guess, but I figured "why not milk this old thread a little more?" .. So, anyone who knows this stuff? __________________ Something Completely Different

01-22-2010, 06:12 PM	#8 (permalink)
Freebase Dali Partying on the inside Join Date: Mar 2009 Posts: 5,584	^ __________________