(b)+DNA+Structure

Complete Biology: page 190 ( Section 11.2 ).

The diagram below shows the link between DNA → protein → Characteristic. This means that a characteristic is formed by different types of proteins in the cell and proteins are made of hereditary DNA.



A DNA molecule is made up of four different chemical compounds called nucleotide or organic bases, and they are as follows: (A) or Adenine is a nucleobase with a variety of roles in biochemistry including cellular respiration, in a form of ATP and NAD and FAD and protien synthesis. (G) or Guanine is paired with cytosine. Guanine is a deriative of purine, consisting of a fused pyrimidine - imidazole ring system (T) or Thymine is a pyrimidine base that is a component of a DNA and (C) or Cytosine is a white pyrimidine occuring in nucleic acids and forms a pair with Guanine

In all organisms, Adenine and Thymine always pair up, and Guanine and Cytosine always match up.

(9) What shape is the DNA molecule (2 special words)? Draw a quick sketch (labeled) to show this shape.

The shape of a DNA molecule is a shape known as the Double Helix. A helix is a geometric shape consisting of two helices around the same axis. A helix is a twisting spiral shape, like a spring. The two helices in a double helix are congruent, meaning that helix may be either right handed or left handed depending on whether it coils clockwise or counter - clock wise. The DNA double helix is right handed and consists of two strands or backbones of phospolate and sugar joined by base pairs of the nucletides Adenine, Thymine, Guanine and Cytosine. In other words, if you know the one base of the double helix, you can know the other side as well. These nucleoides have all the genetic information in the human genome. The "Double Helix" word was first coined by biologists Francis Crick and Dr. James D. Watson.

The diagram below shows this:

Another diagram displaying DNA structure:



Thymine: Nucleobase in nucleic acid found in DNA. In DNA it binds to adenine via 2 hydrogen bonds to stabilize nucleic acid structures Adenine: Nucleobase in nucleic acid found in DNA. It bind to thymine via 2 hydrogen bonds to stabilize nucleic acid structures Cytosine: One of four main bases of DNA. It is a pyrimidine derivative and forms 3 hydrogen bonds along with guanine Guanine: Derivative of purine and is paired with cytosine

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 * Exploring a DNA chain**


 * The sugars in the backbone**

The backbone of DNA is based on a repeated pattern of a sugar group and a phosphate group. The full name of DNA, deoxyribonucleic acid, gives you the name of the sugar present - deoxyribose.

Deoxyribose is a modified form of another sugar called ribose. I'm going to give you the structure of that first, because you will need it later anyway. Ribose is the sugar in the backbone of RNA, ribonucleic acid.

This diagram misses out the carbon atoms in the ring for clarity. Each of the four corners where there isn't an atom shown has a carbon atom.

The heavier lines are coming out of the screen or paper towards you. In other words, you are looking at the molecule from a bit above the plane of the ring.

So that's ribose. Deoxyribose, as the name might suggest, is ribose which has lost an oxygen atom - "de-oxy". The only other thing you need to know about deoxyribose (or ribose, for that matter) is how the carbon atoms in the ring are numbered. The carbon atom to the right of the oxygen as we have drawn the ring is given the number 1, and then you work around to the carbon on the CH2OH side group which is number 5.

You will notice that each of the numbers has a small dash by it - 3' or 5', for example. If you just had ribose or deoxyribose on its own, that wouldn't be necessary, but in DNA and RNA these sugars are attached to other ring compounds. The carbons in the sugars are given the little dashes so that they can be distinguished from any numbers given to atoms in the other rings.

You read 3' or 5' as "3-prime" or "5-prime". || || || Work cited

"DNA Process.jpg." //MediaFire//. Media Fire, 02 Aug. 2011. Web. 06 Feb. 2012. . "DNA." //Wikipedia, the Free Encyclopedia//. Web. 06 Feb. 2012. .

"Nucleic Acid Double Helix." //Wikipedia, the Free Encyclopedia//. Web. 06 Feb. 2012. [].

Sohn, Seung Hyun. //DNA Structure//. Digital image. //Media Fire//. Seung Hyun Sohn. Web. 7 Feb. 2012. [].

"What Is a Double Helix?" //WiseGEEK: Clear Answers for Common Questions//. Web. 06 Feb. 2012. [].

"Cytosine." //Wikipedia, the Free Encyclopedia//. Web. 14 Feb. 2012. [].

"Guanine." //Wikipedia, the Free Encyclopedia//. Web. 14 Feb. 2012. [].

"Thymine." //Wikipedia, the Free Encyclopedia//. Web. 14 Feb. 2012. .