What is DNA

1. What is DNA BY: Grace Cusano

2. What is DNA? • it’s something stored in as a code made up of four chemical bases such as (A) adenine, (G) guanine, (C) cytosine, (T) thymine. • It’s also found in the cell nucleus called nuclear DNA. Some part of it can be found in the Mitochondria. • The unit pairs of the DNA ladder that are paired together are (A),(T) and (C),(G)

3. What DNA does • DNA can replicate itself meaning it can make copies of it’s self. It consist of three billion bases. The order of the sequence of these bases determine the information available for building an organism similar to the way in the letters of the alphabet appear in a certain order to form words and sentences. • DNA, it’s critical when cells divide because each new cell needs an exact copy of DNA from an old cell.

4. Picture of DNA!

5. Spiral ladder of DNA • The spiral ladder of DNA is formed of sugar phosphate. It’s the back bone, such as the like the railings of a stair case. • It’s shaped into a spiral called the double form words and sentences. • It’s a circular ladder with base pairs forming the ladder rings and sugar with phosphate molecules forming the vertical side pieces of the ladder.

6. Picture of DNA Spiral Ladder

7. Function of DNA • It stores the Genetic code of a person or a living thing. • It also provides the code on all life is based, also to pass along all important instructions to the next generation. • Two copies of each chromosome, so each parent can contribute one copy to children • It supports the cells ability to create proteins and RAA to carry out all cellular functions.

8. Genetics • Science of heredity, dealing with resemblances and differences of related organisms resulting from the interaction of their genes and the environment. • It has two copies of each chromosome, so each parent can contribute one copy to children.

9. Gentic pictures

10. Cell Division within the DNA • Division of a cell reproduction or growth. • Duplication in resting phase ensures the equal distribution of the cellular information on the daughter cells formed. • It also occurs in four phrases such as Prophase, Metaphase, Anaphase, and Telophase. • Dividing cells can be studied in living or fixed specimens. Confocal microscopy can be used to image the different stages of mitosis in exquisite detail. Click on the images to see larger versions. • Prophase – Chromosomes that pair up by this time, Chromosomes have replicated so that parent cell has two complete sets. • Metaphase - Chromosomes that align at the equator between both cell formed poles. • Anaphase – Chromosomes that divide, one of each copy of the parents, heading towards each cell formed pole. Then the cell membrane begins to divide. • Telophase – Nuclei appear at either pole and membrane divides. Two cells exist, each have identical chromosomes.

11. DNA Cell Replication • The DNA Replication process Several enzymes and proteins are involved with the replication of DNA. At a specific point, the double helix of DNA is caused to unwind possibly in response to an initial synthesis of a short RNA strand using the enzyme helicase. Proteins are available to hold the unwound DNA strands in position. Each strand of DNA then serves as a template to guide the synthesis of its complementary strand of DNA. DNA polymerase III is used to join the appropriate nucleotide units together. The replication process is shown in graphic on the left. • It is so important that the cells duplicate the DNA genetic material exactly, that the sequence of newly synthesized nucleotides is checked by two different polymerase enzymes. The second enzyme can check for and actually correct any mistake of mismatched base pairs in the sequence. The mismatched nucleotides are hydrolyzed and cut out and new correct ones are inserted.

12. Cell Replication picture and explanation

13. Click for larger image Cell Replication picture

14. DNA Polymerse • A DNA polymerase is an enzyme that cataylzes the polmerization of deoxyribonucleotides into a DNA strand. DNA polymerases are best-known for their feed back role in DNARepication, in which the polymerase "reads" an intact DNA strand as a template and uses it to synthesize the new strand. This process copies a piece of DNA. The newly-polymerized molecule is complementary to the template strand and identical to the template's original partner strand. DNA polymerases use magnesionsas cofactors. Human DNA polymerases are 900-1000 amino acids long.

15. Picture process of Cell Replication

16. DNA Microarray • A DNA microarray is a multiplex technology used in moleculate biology. It consists of an arrayed series of thousands of microscopic spots of DNA OLIGONUCLEOTIDES, called features, each containing PICOMOLES(10−12 moles) of a specific DNA sequence, known as probes(or reporters). These can be a short section of a gene or other DNA element that are used to hydridize a cDNA or cRNA sample (called target) under high-stringency conditions. Probe-target hybridization is usually detected and quantified by detection of fluorophore, silver-, or chemiluminescence-labeled targets to determine relative abundance of nucleic acid sequences in the target. Since an array can contain tens of thousands of probes, a microarray experiment can accomplish many genitictestsinparallel. Therefore arrays have dramatically accelerated many types of investigation.

17. Mitochondrial DNA • Mitochondrial DNA (mtDNA) is DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, ATP. Most other DNA present in eukaryotic organisms is found in the cell nucleus.

18. Identical Twins • Identical twins have almost identical DNA. We used to think identical twins had identical DNA, because they come from the same fertilized egg, which had only one complete set of DNA in the first place.

19. Fraternal Twins • two separate eggs fertilized by two separate sperm to form two separate embryos and then make two separate babies.

20. Work cited • http://www.wonderquest.com/twins-dna.htm • http://www.buzzle.com/articles/fraternal-twins.html