DNA

In Biology Class we study DNA what is DNA?
DNA is made up of a gene?
The gene have letter which they are called nucleotide.
The letters are usually CTAG which pairs are GATC.
There are three main types of RNA?

• messenger RNA- serve as messengers from DNA to the rest of the cell.
• Ribosomal RNA-that make up the major part of Ribsomes
• Transfer RNA-transfer amino acid to ribsomes during protein synthesis.

Gene

• What is a gene

1. A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins.
   


2. sequence of DNA that codes for a protein and thus determines a trait.



3. A hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Genes undergo mutation when their DNA sequence changes.

• How is it controlled?
  

1. A variety of genes are involved in the control of cell growth and division. The cell cycle is the cell’s way of replicating itself in an organized, step-by-step fashion. Tight regulation of this process ensures that a dividing cell’s DNA is copied properly, any errors in the DNA are repaired, and each daughter cell receives a full set of chromosomes. The cycle has checkpoints (also called restriction points), which allow certain genes to check for mistakes and halt the cycle for repairs if something goes wrong

• How do it work?

• What is so special about the DNA of red blood Cell?

1. Red blood cells in mammals do not have a cell nucleus, and therefore do not have DNA; they also do not have other organelles like mitochondria, and produce energy through glycolysis of glucose – a fermentation process – followed by lactic acid production. Their glucose uptake is not regulated by insulin. They are shaped like disks with indentations on top and bottom, optimizing them for exchanging oxygen by maximizing surface area. They are also flexible, allowing them to fit into the tinest capillaries. Adult humans have 2-3 x 1013 red blood cells at any given time, with men and people living in high altitudes having more. Blood types are differentiated by different surface glycoproteins.

• And how is its' specialty adapted to it's function?
  

*a gene can be turn on in off this is called gene regulation.

*Gene regulation can occur at any point during gene expression, but most commonly occurs at the level of transcription (when the information in a gene’s DNA is transferred to mRNA).

*If a cell has an error in DNA it can not be repaired.

• What did the Earth look like years ago?
  Could anybody survive on Earth? If not why?
  Is a virus a living thing (cell)?
  Can a potato absorb in water?
  These are questions I would answer later in this blog.
  
  It was a lifeless, not a surrivable place. A billion years later it was teeming with organisms resembling blue-green algae.
  In one advance Louis Pasteur discredited the concept of spontaneous generation. He offered proof that even bacteria and other microorganisms arise from parents resembling themselves.
  Science shows us that the universe evolved by self-organization of matter towards more and more complex structures. Atoms, stars and galaxies self-assembled out of the fundamental particles produced by the Big Bang In first-generation stars, heavier elements like carbon, nitrogen and oxygen were formed. Aging first-generation stars then expelled them out into space – we, who consist of these elements, are thus literally born from stardust. The heaviest elements were born in the explosions of supernovae. The forces of gravity subsequently allowed for the formation of newer stars and of planets. Finally, in the process of biological evolution from bacteria-like tiny cells (the last universal common ancestor) to all life on earth, including us humans, complex life forms arose from simpler ones.