DNA - a nucleic acid
DNA stands for deoxyribonucleic acid. In eukaryotic cells, you will find DNA in the nucleus. DNA is one of the nucleic acids, information-containing molecules in the cell (ribonucleic acid, or RNA, is the other nucleic acid). DNA is a record of instructions telling the cell what it's job is going to be. A good analogy for DNA as a whole is a set of blueprints for the cell, or computer code telling a PC what to do.
When a cell is in its normal state, the DNA is not duplicating and it just looks like a blob of white strands. Scientists use the word chromatin to describe that DNA. When it is time for the cell to reproduce, they condense and wrap up very tightly. The tightly wound DNA is called a chromosome. Although it may look complicated, the DNA is really just a macromolecule made up of four different parts called nucleotides. The nucleotide in DNA consists of a sugar (deoxyribose), a phosphate group, and one of four nitrogen bases (cytosine (C), thymine (T), adenine (A), guanine (G)). The nitrogen bases point inward making up the "rungs" of DNA's twisted ladder. They follow a base pair rule: A with T and C with G. Here's a helpful activity to learn the structure of DNA and base pairing:
http://learn.genetics.utah.edu/content/molecules/builddna/ DNA ReplicationDNA carries the information for making all of the cell's proteins. These proteins implement all of the functions of a living organism and determine the organism's characteristics. When the cell reproduces, it has to pass all of this information on to the daughter cells.
Before a cell can reproduce, it must first replicate, or make a copy of, its DNA. DNA replication is the process of producing two identical copies from one original DNA molecule. Play this game to learn about DNA replication: http://www.nobelprize.org/educational/medicine/dna_double_helix/ |
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Upon popular demand, here is the intro to DNA video I played in class before we started notes:
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Making RNA (Transcription) and Protein Synthesis (Translation)
Helpful animations and videos about transcription and translation:
Transcription animation
Glencoe's Making RNA interactive lab
University of Utah's Transcribe and Translate a Gene Activity
Transcription animation
Glencoe's Making RNA interactive lab
University of Utah's Transcribe and Translate a Gene Activity
TED Ed video about Protein Synthesis:
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