Chapter four: carbon and the molecular diversity of life

Diagram: Stanley Miller in 1953 set up a similar condition as origin earth. He first evaporated water and mixed gas of water with methane, hydrogen, and ammonia. Some simple organic molecules were formed under cooling and lightning. After all the organic molecules may have been synthesized abiotically on the early Earth.


Main Questions:

1. Organic chemistry is currently defined as?

A: the study of carbon compounds.

2. Which action could produce a carbonyl group?

A: the replacement of the –OH of a carboxyl group with hydrogen.

3. What kind of chemical group is most likely to be responsible for an organic molecule behaving as a base?

A: amino.

Main Facts:

1. In 1953, Stanley Miller at the University of Chicago set up a laboratory simulation of chemical conditions on the primitive Earth and demonstrated the spontaneous synthesis of organic compounds.

2. With a total of 6 electrons, a carbon atom has 2 in the first electron shell and 4 in the second shell.

3. One function of phosphate groups is to transfer energy between organic molecules.

4. If the carbonyl group is on the end of the skeleton, the compound is an aldehyde. If the carbonyl group is within the carbon skeleton, then the compound is a ketone.

5. A carboxyl group acts as an acid because the combined electronegativities of the two adjacent oxygen atoms increase the dissociation of hydrogen as an ion (H⁺). An amino group (—NH₂) consists of a nitrogen atom bonded to two hydrogen atoms and the carbon skeleton.

Summary:

Although cells have 70–95% water, the rest consists mostly of carbon-based compounds. Carbon is unparalleled in its ability to form large, complex, and diverse molecules. Such as Proteins, DNA, carbohydrates, and other molecules that distinguish living matter from inorganic material are all composed of carbon atoms bonded to each other and to atoms of other elements. These other elements commonly include hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), and phosphorus (P).

Basically the study of carbon compound(organic chemistry) which is dealing with any compound with carbon.

Key terms:

1. Hydrocarbons: organic molecules consisting of only carbon and hydrogen.

2. Isomer: compounds that have the same numbers of atoms of the same elements but different structures and hence different properties.

3. Structural isomers: is a form of isomerism in which molecules with the same molecular formula have atoms bonded together in different orders, as opposed to stereoisomerism.

4. Geometric isomers: one of several compounds that have the same molecular formula and covalent arrangements but differ in the spatial arrangements of their atoms owing to the inflexibility of double bonds.

5. Enantiomers: one of two compounds that are mirror images of each other.

6. Functional groups: A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and usually involved in chemical reactions.

7. Adenosine triphosphate: An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. The energy is used to drive endergonic reactions in cells.

8. Methyl group: A chemical group consisting of a carbon bonded to three hydrogen atoms. The methyl group may be attached to a carbon or to a different atom.

9. Phosphate group: A chemical group consisting of a phosphorus atom bonded to four oxygen atoms; important in energy transfer.

10. Sulfhydryl group: A chemical group consisting of a sulfur atom bonded to a hydrogen atom.

Video: http://www.youtube.com/watch?v=vn_HICkswI4