Heres some updates from the colorful world of science:
(1) People are trying to stop planes flying over the grand canyon
There are well over 100 planes and choppers flying over the Grand Canyon each day. The whiny tourists are cracking the shits, so they are kicking up a stink about it. It was meant to be taken care of about 22 years ago, but it never went through, so the tourists are having another crack at being major fucking whiners. "The Grand Canyon may look the same but it does not sound the same" a whiny tourist is quoted as saying.
(2) The US is finally getting around to doing something about greenhouse emissions.
The Seppos are finally biting the bullet and passing a bill to reduce the emissions to 17% below 2005 levels by 2020. Some companies are going to be coughing up dough to give to Uncle Sam for their emissions as well, supposedly 5% of the cash is gonna help reforestration projects. See what happens when you don't have a redneck criminal bigoted faschist pig of a president at the helm? (Dubya everyones looking at you!) things actually start to get done!
(3) Shellfish reefs are getting their asses handed to them.
Poor little buggers. They provide us with tasty meals, their reefs protect our shores from erosion, shelter other organisms, they filter organic dirt form the water and they have been all round decent folks to us. And THIS is how we treat them??? 85% of all reefs are now fuckin DEAD!! Because we are stupid fucks, we are only just now realising that shellfish are more then a tasty snack.
Monday, June 8, 2009
Sunday, June 7, 2009
Intro to cells
Cells are the building blocks of life. All life is either made of cells or is a cell.
Think of a cell like a balloon full of water. The balloon is the membrane. Holding all the bits inside, and the water is the gel, with all the chemicals and necessary parts for the cell to do stuff. The gel and membrane are mind numbingly complex, which is why you gotta take it slow and gradually build your knowledge up rather then just try to learn it all at once, your head might explode.
We are multi celled organisms. We are made up of many, many, many different kinds of cells, which all perform different functions to help us eat, sleep, breathe etc.
There are anywhere from 10-100 million species of living things in the world, this means ALOT of different types of cells.
Cells can vary ridiculously in size, anywhere from 1 micrometer to 1 millimeter in diameter.
They vary in shape, some nerve cells are 10,000x longer then they are thick. Some examples to demonstrate the diversity of cells include:
(1) Paramecium
Submarine shaped, is covered in 10s of thousands of cilia, which is like hair, and moves the cell. Paramedium can be found in ponds.
(2) Plant cells
Immobile prisms found at the surface layers of the plant, surrounded by a chemical called cellulose, then another layer on top of THAT of wax.
(3) Bdellovibrio
Bacteria, sausage shaped, driven by a rotating corkscrew shaped instrument called a flagellum which propels it through water.
(4) Macrophage AKA white blood cells
These little buggers go through an animals body getting rid of evil microorganisms, cleaning up dead and dying cells and whatnot.
Back to the water baloon analogy, some cells only have one plasma membrane protecting them, other cells take it one step further and coat themselves AGAIN, in some slimy gooey shit. This slimey goo builds up into cell walls. So EVERY cell has a cell membrane, and some of the cells also have a cell wall on top of that, imagine coating bees wax on the water balloon, and it hardens, this is a way of visualising it.
In most respects, cells can be so insanely different, that a chemical a cell needs to survive, like oxygen, could be fatally harmful to another kind of cell. Some cells only need air, water and sunlight to survive, others need a complex mixture of stuff from other cells etc.
Some cells can be little factories for particular chamicals e.g. hormones. Some are engines, using stuff to make energy, some cells can even generate electricity.
Some cells are so specialised that they cannot live on their own, they need to be a part of a multicellular organism, where they can rely on other cells for support.
What do cells have in common?
Discoveries in biochemistry and molecular biology have really helped us know what the true nature of a cell is. All cells share common machinery to do their usuall stuff, alot of their chemistry is essentially alike, and all cells rely on DNA to store their genetic information. Of course we all know what DNA is, if you do not, here is a basic article on DNA 101 http://simple.wikipedia.org/wiki/DNA. Basically DNA contains the information about the structure and function of the proteins that make up the cell, being as most of a cell is made up of proteins. DNA is transcribed into its cousin molecule, RNA, which is then translated into proteins. Think of DNA as an instruction booklet on how to build a car. The proteins are the building materials for the car. The RNA is you looking at the book and reading it, then building the car.
Proteins are made up of simpler molecules called amino acids, which are stuck together in a chain. There are 20 different kinds of amino acids used to make these proteins, they can be arranged in any kind of order. The order the amino acids are in determines the chemical makeup of the protein and hence it's structure and function. Just like rearranging letters differently in a collection of letters can make them collectively convey a different word and meaning.
If something doesnt have all the features of a cell, it is not considered living. E.g. a virus does not have the ability to reproduce by itself, they need to invade a host and use the host's repoductive bits to do the work. Hence viruses are like chemical zombies, only harmful once they are inside a host.
All life shares a common parent, i.e. a single cell floating in the primordial sea is the ancestor of all living life. A cell reproduces by duplicating its DNA then splitting into 2 cells. Sometimes the copying of the DNA fucks up a little bit, this is called a mutation. Using the car analogy, if the car instruction book is altered a bit, then the car will be built a little differently. The mutation can be beneficial, helping the organism to survive and reproduce more effectively, it can be neutral, or it can be a hindrance to the organism, which will result in the mutated organism not surviving to reproduce. This is the principle of natural selection. Beneficial mutations increase an organisms ability to reproduce and spread its genes, bad mutations are weeded out. This is responsible for all the complexity and adaptation of life we see today. The concept of evolution and a universal common ancestor explains why all of life is all so fundamentally similair.
The genome is the correct terminology for the DNA instruction booklet. It is basically defined as the totality of the genetic information present in an organisms DNA.
There are many different types of cells in a multi cellular organism. These differentiated cell types are generated all from a single fertilized egg cell. All cells in a particular organism contain the entire genome of that organism. But if all cells in an organism contain the same genome, why the hell are they all different??????
This is because different cells express different genes. i.e. they all have the same instruction booklet, but they can be selective about which bits of the booklet to read. They can read a couple of bits and ignore the rest, hence this is responsible for the uniqueness of the structure and function of particular cells in the organism. There are different factors which ultimately determine which genes end up being expressed, mostly cues from the surroundings.
Imagine Leonardo da Vinci trying to use a modern day laptop. At first he would be befuddled, but after he had a couple of years of trying to learn as much about it as he can, he would then try to discover how it works on the inside, which he eventually would. This is analogous to scientists first discovering the cell and how perplexed they were when they tried to figure out how they work.
Cells could not be seen untill the invention of microscopes in the seventeenth century. The term 'cell' was actually used to describe the little chambers found when you examine cork under a microscope, which was done by Robert Hooke. The name then stuck and was applied to the building blocks of life as well when they were discovered.
The microscope really began to be frequented to look at cells in the 19th century, before that it was a rich commodity.
The birth of biology began with the release of 2 papers by Theodore Schwann and Matthais Schleiden, in 1838 and 1839 respectively. They looked at plant and animal tissues via microscope and concluded they were made of cells. They also developed idea that cells reproduced by dividing. These ideas accumulated into cell theory. It also included the idea that life can only come from pre-existing life (biogenesis), which is true in this day and age, but not back in the times of early earth when the conditions for the formation of life from non life were more favourable. It also included the principles of inheritance i.e. the tendency for offspring to inherent parent characters.
Evolution is mentioned quite frequently in the context of biology, being as all biological studies seem to make much more sense with the acceptance of evolutionary theory.
If you look at a slice of plant or animal tissue under the microscope, you will see thousands of small cells. they are either squished together or seperated by an extracellular matrix. Think of the cells as balloons again, now visualise the extracellular matrix as a pool of thick gooey stuff in which the balloons are suspended. For chemical reasons it keeps the cells a little bit apart from each other. The extracellular matrix is made from protein fibers coccooned inside a polysaccharide gel, and it is very thick and DENSE. I will talk about what a polysaccharide is a little later.
The typical cell is around 5-20 micrometers in diameter. If you have looked after your cells, they should be moving around a bit under the microscope. If you got patience, you can watch a cell divide into 2 under the microscope.
The internal bits of a cell are hard to see because
Think of a cell like a balloon full of water. The balloon is the membrane. Holding all the bits inside, and the water is the gel, with all the chemicals and necessary parts for the cell to do stuff. The gel and membrane are mind numbingly complex, which is why you gotta take it slow and gradually build your knowledge up rather then just try to learn it all at once, your head might explode.
We are multi celled organisms. We are made up of many, many, many different kinds of cells, which all perform different functions to help us eat, sleep, breathe etc.
There are anywhere from 10-100 million species of living things in the world, this means ALOT of different types of cells.
Cells can vary ridiculously in size, anywhere from 1 micrometer to 1 millimeter in diameter.
They vary in shape, some nerve cells are 10,000x longer then they are thick. Some examples to demonstrate the diversity of cells include:
(1) Paramecium
Submarine shaped, is covered in 10s of thousands of cilia, which is like hair, and moves the cell. Paramedium can be found in ponds.
(2) Plant cells
Immobile prisms found at the surface layers of the plant, surrounded by a chemical called cellulose, then another layer on top of THAT of wax.
(3) Bdellovibrio
Bacteria, sausage shaped, driven by a rotating corkscrew shaped instrument called a flagellum which propels it through water.
(4) Macrophage AKA white blood cells
These little buggers go through an animals body getting rid of evil microorganisms, cleaning up dead and dying cells and whatnot.
Back to the water baloon analogy, some cells only have one plasma membrane protecting them, other cells take it one step further and coat themselves AGAIN, in some slimy gooey shit. This slimey goo builds up into cell walls. So EVERY cell has a cell membrane, and some of the cells also have a cell wall on top of that, imagine coating bees wax on the water balloon, and it hardens, this is a way of visualising it.
In most respects, cells can be so insanely different, that a chemical a cell needs to survive, like oxygen, could be fatally harmful to another kind of cell. Some cells only need air, water and sunlight to survive, others need a complex mixture of stuff from other cells etc.
Some cells can be little factories for particular chamicals e.g. hormones. Some are engines, using stuff to make energy, some cells can even generate electricity.
Some cells are so specialised that they cannot live on their own, they need to be a part of a multicellular organism, where they can rely on other cells for support.
What do cells have in common?
Discoveries in biochemistry and molecular biology have really helped us know what the true nature of a cell is. All cells share common machinery to do their usuall stuff, alot of their chemistry is essentially alike, and all cells rely on DNA to store their genetic information. Of course we all know what DNA is, if you do not, here is a basic article on DNA 101 http://simple.wikipedia.org/wiki/DNA. Basically DNA contains the information about the structure and function of the proteins that make up the cell, being as most of a cell is made up of proteins. DNA is transcribed into its cousin molecule, RNA, which is then translated into proteins. Think of DNA as an instruction booklet on how to build a car. The proteins are the building materials for the car. The RNA is you looking at the book and reading it, then building the car.
Proteins are made up of simpler molecules called amino acids, which are stuck together in a chain. There are 20 different kinds of amino acids used to make these proteins, they can be arranged in any kind of order. The order the amino acids are in determines the chemical makeup of the protein and hence it's structure and function. Just like rearranging letters differently in a collection of letters can make them collectively convey a different word and meaning.
If something doesnt have all the features of a cell, it is not considered living. E.g. a virus does not have the ability to reproduce by itself, they need to invade a host and use the host's repoductive bits to do the work. Hence viruses are like chemical zombies, only harmful once they are inside a host.
All life shares a common parent, i.e. a single cell floating in the primordial sea is the ancestor of all living life. A cell reproduces by duplicating its DNA then splitting into 2 cells. Sometimes the copying of the DNA fucks up a little bit, this is called a mutation. Using the car analogy, if the car instruction book is altered a bit, then the car will be built a little differently. The mutation can be beneficial, helping the organism to survive and reproduce more effectively, it can be neutral, or it can be a hindrance to the organism, which will result in the mutated organism not surviving to reproduce. This is the principle of natural selection. Beneficial mutations increase an organisms ability to reproduce and spread its genes, bad mutations are weeded out. This is responsible for all the complexity and adaptation of life we see today. The concept of evolution and a universal common ancestor explains why all of life is all so fundamentally similair.
The genome is the correct terminology for the DNA instruction booklet. It is basically defined as the totality of the genetic information present in an organisms DNA.
There are many different types of cells in a multi cellular organism. These differentiated cell types are generated all from a single fertilized egg cell. All cells in a particular organism contain the entire genome of that organism. But if all cells in an organism contain the same genome, why the hell are they all different??????
This is because different cells express different genes. i.e. they all have the same instruction booklet, but they can be selective about which bits of the booklet to read. They can read a couple of bits and ignore the rest, hence this is responsible for the uniqueness of the structure and function of particular cells in the organism. There are different factors which ultimately determine which genes end up being expressed, mostly cues from the surroundings.
Imagine Leonardo da Vinci trying to use a modern day laptop. At first he would be befuddled, but after he had a couple of years of trying to learn as much about it as he can, he would then try to discover how it works on the inside, which he eventually would. This is analogous to scientists first discovering the cell and how perplexed they were when they tried to figure out how they work.
Cells could not be seen untill the invention of microscopes in the seventeenth century. The term 'cell' was actually used to describe the little chambers found when you examine cork under a microscope, which was done by Robert Hooke. The name then stuck and was applied to the building blocks of life as well when they were discovered.
The microscope really began to be frequented to look at cells in the 19th century, before that it was a rich commodity.
The birth of biology began with the release of 2 papers by Theodore Schwann and Matthais Schleiden, in 1838 and 1839 respectively. They looked at plant and animal tissues via microscope and concluded they were made of cells. They also developed idea that cells reproduced by dividing. These ideas accumulated into cell theory. It also included the idea that life can only come from pre-existing life (biogenesis), which is true in this day and age, but not back in the times of early earth when the conditions for the formation of life from non life were more favourable. It also included the principles of inheritance i.e. the tendency for offspring to inherent parent characters.
Evolution is mentioned quite frequently in the context of biology, being as all biological studies seem to make much more sense with the acceptance of evolutionary theory.
If you look at a slice of plant or animal tissue under the microscope, you will see thousands of small cells. they are either squished together or seperated by an extracellular matrix. Think of the cells as balloons again, now visualise the extracellular matrix as a pool of thick gooey stuff in which the balloons are suspended. For chemical reasons it keeps the cells a little bit apart from each other. The extracellular matrix is made from protein fibers coccooned inside a polysaccharide gel, and it is very thick and DENSE. I will talk about what a polysaccharide is a little later.
The typical cell is around 5-20 micrometers in diameter. If you have looked after your cells, they should be moving around a bit under the microscope. If you got patience, you can watch a cell divide into 2 under the microscope.
The internal bits of a cell are hard to see because
- they are really tiny
- they are transparent
This is where cell dyes come in. There are certain dyes that color certain bits of the cell so you can see it. Or scientists take advantage of a process called refraction i.e. different bits of the cell bend light more strongly then other bits. Scientists use this to make an image of the cell, which is then further enhanced by image processing. With a light microscope, you cannot see things smaller then 0.2 micrometers.
The revealed cell thus far has:
- A distinct boundary (membrane, sometimes the cell wall too)
- a nucleus in the middle
- Gooey stuff that fills up the cell and is the medium in which everything happens (cytoplasm), it is the water in the water balloon analogy
- Tiny objects called organelles inside the cell which are analogous to organs inside our body.
If you want to magnify things even further, then you have to switch to something more high powered, this is where electron microscopes come in. It can examine things down to a few nanometers. Preparing cells to examine with an EM is a pain-in-the-fucking-arse!!!!!
Here are the steps:
- Preserve/pickle sample in solution (fixing)
- Embedd in hard wax/resin
- Section into thin slices
- Stain so you can see it
These steps apply for the light microscope too, but with an EM the sections have to be thin as fuck! and you CANNOT look at wet cells.
Under an EM, you can clearly see the organelles, the cell membrane/plasma membrane in detail (about 5 nanometres thick, or the equivalent of 2 large molecules), plus internal membranes around the organelles as well (same thickness). You can even see some of the really big molecules inside the cell, that is how powerful the EM is.
There are 2 types of EM.
- Transmission Electron Microscope (TEM), exactly the same as a light microscope, but it uses a beam of electrons insteadof a beam of light.
- Scanning Electron Microscope (SEM), bounces electrons off the sample, so its really good for examining the surface of the sample.
Procaryotes are single celled organisms with no nucleus. Bacteria is a type of procaryote, it basically has the bare essentials to survive and reproduce. Bacteria has no organelles. Cells that do have a nucleus are called prokaryotes.
Anyway, that is all for now, I will be posting 2 more long ass articles then having a break.
Science updates.
Some recent happenings in the world of science:
(1) Soccer-playing robots have learned how to fall properly
Some scientists basically did a physical analysis of the least stressful way the robot could fall, then programmed these parameters into the robots CPU. Arsehole robots will probably start deliberately falling over during soccer games and screaming "UMPIE!", another human quality to learn: cheating.
(2) The mystery that is placebo's evil twin: nocebo
Most scientists laughed off the idea that nocebo could have a serious impact upon someones health, but recent developements have suggested that it is to be taken seriously. Simply believing something is bad for you can have very adverse consequences they have found.
(3) Budget is too short to go to the moon
Apparently the budget for NASA this year is 3.1 billion shorter then expected, so the hopes of getitng to the moon by 2020 have been dashed for now. I dimly suspect this is temporary though.
(4) Blue whales are dumb
After retreating to California waters in response to being whaled to fuckin death by the Japs, Blue whales are slowly coming back to Pacific waters off North America. Probably because there isnt enough food around California, since everyone fuckin starves themselves there to be skinny, but scientists reckon we can scapegoat global warming for it as well, since global warming is meant to somehow reduce the krill population, the tucker of choice when the whales come down with a bad case of the munchies.
(5) Darwin is majorly pissed off.
Some people know about the fetish Darwin had for birds on the Galagpos islands, he used these birds to offer supporting evidence for speciation (where new species are created from old ones). Well the dead motherfucker is turning in his grave as we speak. The medium tree finch, one of his BFF birds, is endangered and slowly inching closer to extinction. It is joining the other 191 species of birds on the endangered species list. They reckon the main reason is these greedy little parasitic flies that are also on the island, have an affinity for medium tree finches, and like to suck the life out of them because, well, they taste good. Poor little buggers.
(6) Get ready for juiced up zombies, they are gonna be eating designer BRAIINNNNSSSS!!!
Genetic enhancement, mechanical implants, downloadable computer software and information, this is all becoming a reality for our favourite clump of newurons and grey matter between our ears. We are entering an age of intellectual badassery. Forget tattooes, forget how many bad ass life threatening stunts you have done, this is the new wave of mental extremity. Imagine being able to say to mates that you are an expert physician, surgeon, biologist, computer scientist, mechanical engineer, political scientist, comedian, pick up artist, actor, musician, economist, systems analyst and mathematician all in one - and you downloaded it into your head five minutes ago?? That is the shit man.
Thats all for now
(1) Soccer-playing robots have learned how to fall properly
Some scientists basically did a physical analysis of the least stressful way the robot could fall, then programmed these parameters into the robots CPU. Arsehole robots will probably start deliberately falling over during soccer games and screaming "UMPIE!", another human quality to learn: cheating.
(2) The mystery that is placebo's evil twin: nocebo
Most scientists laughed off the idea that nocebo could have a serious impact upon someones health, but recent developements have suggested that it is to be taken seriously. Simply believing something is bad for you can have very adverse consequences they have found.
(3) Budget is too short to go to the moon
Apparently the budget for NASA this year is 3.1 billion shorter then expected, so the hopes of getitng to the moon by 2020 have been dashed for now. I dimly suspect this is temporary though.
(4) Blue whales are dumb
After retreating to California waters in response to being whaled to fuckin death by the Japs, Blue whales are slowly coming back to Pacific waters off North America. Probably because there isnt enough food around California, since everyone fuckin starves themselves there to be skinny, but scientists reckon we can scapegoat global warming for it as well, since global warming is meant to somehow reduce the krill population, the tucker of choice when the whales come down with a bad case of the munchies.
(5) Darwin is majorly pissed off.
Some people know about the fetish Darwin had for birds on the Galagpos islands, he used these birds to offer supporting evidence for speciation (where new species are created from old ones). Well the dead motherfucker is turning in his grave as we speak. The medium tree finch, one of his BFF birds, is endangered and slowly inching closer to extinction. It is joining the other 191 species of birds on the endangered species list. They reckon the main reason is these greedy little parasitic flies that are also on the island, have an affinity for medium tree finches, and like to suck the life out of them because, well, they taste good. Poor little buggers.
(6) Get ready for juiced up zombies, they are gonna be eating designer BRAIINNNNSSSS!!!
Genetic enhancement, mechanical implants, downloadable computer software and information, this is all becoming a reality for our favourite clump of newurons and grey matter between our ears. We are entering an age of intellectual badassery. Forget tattooes, forget how many bad ass life threatening stunts you have done, this is the new wave of mental extremity. Imagine being able to say to mates that you are an expert physician, surgeon, biologist, computer scientist, mechanical engineer, political scientist, comedian, pick up artist, actor, musician, economist, systems analyst and mathematician all in one - and you downloaded it into your head five minutes ago?? That is the shit man.
Thats all for now
first post.
Hey,
I am intending this blog to educate laypeople on basic facts of biology, and cell structure and function.
I will ALSO be reporting recent happenings in science, like new discoveries and advancements in the scientific community.
So enjoy, and dont forget to comment.
I am intending this blog to educate laypeople on basic facts of biology, and cell structure and function.
I will ALSO be reporting recent happenings in science, like new discoveries and advancements in the scientific community.
So enjoy, and dont forget to comment.
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