(b)+DNA+Structure

(4) Complete Biology: page 190 ( Section 11.2 ).

Deoxyribonucleic acid (commonly known as DNA) is a chain of nucleic acid which holds information for development and functioning for all known living beings. These chains of genetic material are organised into chromosomes.

The diagram below shows that the set of DNA (gene) controls the protein in the cells from the nucleus and because of this it alters the characteristics of a person as a whole by each individual cell.



A DNA molecule is made up of nucleotides which mainly contains a base and sugar phosphate back bone. MIllions of them are added together in different combinations (within the DNA) which is why genes are varied. The nucleotides are combined like rungs on a ladder.



There are 4 different nucleotides in DNA

Adrenine (A) Thymine (T) Guanine (G) Cytosine (C).



The base pair of a DNA is either one of two types, either adenine (A) with thymine (T) or guanine (G) with cytosine (C)

Adenine and guanine are purines which is larger type of DNA. the diagram below shows the detailed structure of these two//.(Hallick)// The atoms that make up the rings are numbered from 1-9 and all ring atoms lie in the same place. There are 5 carbon and four nitrogen atoms making up the fused rings.



Cytosine and thymine are pyrimidines which is not large compare to other two. the diagram below shos the detailed structre of there two.//(Hallick)// The atoms that make up the ring are numbered from 1-6 and all ring atoms lie in the same place, similar to the purines above. There are 4 carbon and 2 nitrogen atoms making up the ring.



media type="youtube" key="PDeaLxoL75M" height="315" width="560"

the nucleotides that make up DNA molecules are combined and then coiled together in a double helix form by hydrogen bonds.This is what a chromosome is.

(Biology Helix)

This video further demonstrates the structure of DNA

media type="youtube" key="qy8dk5iS1f0" height="315" width="420"

Work Cited

"Biology Helix." //Technyou//. N.p., n.d. Web. 6 Feb. 2012.

.

"DNA, proteins and the characteristics of organisms." //Complete Biology//. Print.

helix.jpg>.

"DNA." // Wikipedia, the Free Encyclopedia //. Web. 09 Feb. 2012. [].

 "James Watson Explains DNA Basepairing - YouTube." //YouTube - Broadcast Yourself. // Web. 16 Feb. 2012. .

Hallick, Richard B. "Introduction to DNA Structure." __Biology Learning Center at the University of Arizona__. 1995. 14 Feb. 2012 [].

__DNA Structure__. Dir. Ppornelubio. __YouTube__. 13 Sept. 2006. 16 Feb. 2012 .