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chapter 4
book work
Question | Answer |
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why was wohler astonished to find he had made urea? | prior to wohler's experiment, the prevailing view was that only living organisms could synthesize "organic" compounds. Wohler made urea, an organic compound without the involvement of living organisms. |
when miller tried his experiment with out the electrical discharge, no organic compounds were found. What might explain this result?* | the spark provided energy needed for the inorganic molecules in the atmosphere to react with each other* |
Draw a structural formula for C2H4 | double bonded carbons in the middle with Hs off to the sides |
what makes a molecule an isomer and differentiate between the different kinds of isomers* | isomers are compounds that have the same number of atoms of the same elements but different structures with different properties. Structural= differ covalent arrangement, cis trans have covalent bonds the same but different spacial arrangement. |
continued* | enantiomers are isomers that mirror images of each other differing in shape from asymmetric carbon one attached to four different atoms |
what does the term amino acid signify about the structure of such a molecule? | it has an amino group, which makes it an amine, and a carboxyl group which makes it a carboxylic acid |
How are gasoline and fat chemically similar? | both consist largely of hydrocarbon chains |
can propane C3H8 form an isomer? | no because there is not enough diversity in the atoms. It can't form structural isomers because there is only one way for three carbons to attach to each other. There is no double bonds so cis trans isomers is not possible. Each carbon molecule has two |
continued | hydrogen attatched so the molecule is symmetrical and cannot have enantiomers |
what chemical change occurs to ATP when it reacts with water and releases energy? | ATP molecule loses a phosphate, becoming ADP |
Suppose you had an organic molecule such as cysteine and you chemically removed the NH2 group and replaced it with -COOH. Draw the structural formula this molecule and speculate about its chemical properties. Is the central carbon asymetric? | a group that can act as a base is replaced by a group that can act as an acid, increasing the acidic properties of the molecules with which it can interact. The original cysteine molecule has an asymmetric carbon in the center. After replacement of the |
continued | amino group with a carboxyl group, this carbon is no longer asymmetric |
How did Stanley Miller's experiment extend the idea of mechanism to the origin of life | Miller showed that organic molecules could form under the physical and chemical conditions estimated to have been present on early earth. Abiotic synthesis of organic molecules would have been a first step to the origin of life |
what type of isomers are acetone and propanal? How many asymmetric carbons are present in acetic acid, glycine and glyceral phosphate? Can these three molecules exist as forms that are enantiomers?figure 4.9 | Acetone and propanal are structural isomers. Acetic acid and glycine have no asymmetric carbons, whereas glycerol phosphate has one. Therefore glyerol phosphate can exist as forms that are enantiomers, but acetic acid and glycine cannot. |
In what ways does a methyl group differ chemically rom the other six important chemical groups? | methyl group is nonpolar and not reactive. The other six groups are called functional groups. They are each hydrophilic, increasing the solubility of organic compounds in water, and can participate in chemical reactions |
organic chemistry is defined as? | the study of carbon compounds |
which chemical group is most likely to be responsible for an organic molecule behaving as a base? | amino |
which of the following hydrocarbons has a double bond in its carbon skeleton? | c2h2 |
what term correctly describes the relationship between two sugars number 5 page 67 | structural isomers |
how do you identify an asymmetric carbon* | if the charges opposite of eachother are equal but negative or positive then it is asymmetric* |
give an example of an action that could produce a carbonyl group | the replacement of the -oh of a carboxy group with a hydrogen |
what properties does silicon share with carbon that would make silicon based life more likley than, say, neon- based life or aluminum based life | since it has 4 valence electrons, just like carbon, silicon would be able to form long chains, including branches, that could act as skeletons for large molecules. It would do better than neon with no valence or aluminum with only three. |