Chapter 4 - Carbon and the Molecular Diversity of Life

You will need to master the chart and the information in it. Using the functional groups above, see if you can answer the following prompts: a. -NH2 b. Can form cross-links that stabilize protein structure c. Key component of ATP d. Can affect gene expression e. CH3 f. Is always polar g. Determines the two groups of sugars h. Has acidic properties i. -COOH j. Acts as a base k. Circle and identify three functional groups in the molecule shown above

Amino groups are written -NH2. Sulfhydryl groups can form cross-links that stabilize protein structure. Phosphate is a key component of ATP. Methyl groups can affect gene expression and are written -CH3. Hydroxyl is always polar. Carbonyl determines the two groups of sugars. Carboxyl has acidic properties and a carboxyl group is written -COOH. Amino acts as a base

In Chapter 2 you learned what an isotope is. Since students often confuse this word with isomer, please define each term here and give an example.

An isotope is an alternative form of the same element containing an equal number of protons but a different number of neutrons in its atomic nucleus, and thus some different properties. C-12, C-13 and C-14 are isotopes of the element carbon. An isomer is an alternative form of the same compound with the same formula but a different arrangement of atoms in the molecule, and thus different properties. Pentane and 2-methylbutane are structural isomers of each other.

Use this figure to identify the three types of isomers. For each type, give a key character and an example.

Structural isomers such as pentane and 2-methylbutane differ in the covalent arrangements of their atoms; the locations of double bonds may also vary. Geometric isomers such as rhodopsin's have the same covalent partnerships, but differ in their spatial arrangements due to the inflexibility of double bonds, which must be reassembled as, unlike single bonds, they cannot simply be rotated. An atom or group of atoms attached to a double-bonded carbon may be on the same side (cis) or on opposite sides (trans). Enantiomers such as ibuprofen's differ in spatial arrangement around an asymmetric carbon, resulting in molecules that are mirror images of each other and thus named L or D after the Latin terms for left and right (levo and dextro, respectively)

Identify the three types of isomers. For each type, give a key character and an example.

Structural isomers such as pentane and 2-methylbutane differ in the covalent arrangements of their atoms; the locations of double bonds may also vary. Geometric isomers such as rhodopsin's have the same covalent partnerships, but differ in their spatial arrangements due to the inflexibility of double bonds, which must be reassembled as, unlike single bonds, they cannot simply be rotated. An atom or group of atoms attached to a double-bonded carbon may be on the same side(cis) or on opposite sides (trans). Enantiomers such as ibuprofen's differ in spatial arrangement around an asymmetric carbon, resulting in molecules that are mirror images of each other and thus named L or D after the Latin terms for left and right (levo and dextro, respectively).

Here is an idea that will recur throughout your study of the function of molecules: Change the structure, change the function. You see this in enantiomers, you will see it in proteins and enzymes, and now we are going to look at testosterone and estradiol. Notice how similar these two molecules are, and yet you know what a vastly different effect each has. Label each molecule in the sketch below, and circle the differences.

Testosterone has an O double-bonded to its first carbon ring, instead of estradiol's single-bonded OH (1). Estradiol has two more double-bonds in its first carbon ring than testosterone does (2). Finally, testosterone has a methyl group attached to it (3) which estradiol lacks.

Enantiomers

- Enantiomers -Are important in the pharmaceutical industry

What are Isomers ? What are the three types of isomers ?

- Isomers -Are molecules with the same molecular formula but different structures and properties - Three types of isomers are -Structural -Geometric -Enantiomers

Organic chemistry is the study of _______________________ compounds Organic compounds range from ________________ molecules to ________________ ones

- Organic chemistry is the study of carbon compounds - Organic compounds range from simple molecules to colossal ones

Give one example of enantiomers that vary in their pharmacological effect.

Albuterol is used to relax bronchial muscles, improving airflow in asthma patients. Only the effective R-Albuterol is marketed as the ineffective S-Albuterol form counteracts the active R form.

What is a hydrocarbon? Name two. Are hydrocarbons hydrophobic or hydrophilic?

Hydrocarbons are hydrophobic molecules consisting of only carbon and hydrogen, such as benzene and methane. -Are found in many of a cell's organic molecules

What was collected in the sample for chemical analysis? What was concluded from the results of this experiment?

Miller collected several organic compounds, both simple (such as formaldehyde) and complex (such as hydrocarbons), commonly found in organisms. Though his methodology is not undisputed, his results support the concept that abiotic synthesis of organic compounds could have been an early stage in the origin of life

•Carbon chains -Form the skeletons of most organic molecules -Vary in length and shape

Carbon chains -Form the skeletons of most organic molecules -Vary in length and shape

Make an electron distribution diagram of carbon. It is essential that you know the answers to these questions: a. How many valence electrons does carbon have? b. How many bonds can carbon form? b. What type of bonds does it form with other elements?

Carbon has 4 valence electrons, can bond to 4 items, and typically forms covalent bonds with other elements

Carbon chains form skeletons. List here the types of skeletons that can be formed

Carbon skeletons vary in length. The skeleton may have double bonds, which can vary in location. Skeletons may be branched or unbranched. Some carbon skeletons are arranged in rings.

Functional groups

Functional groups -Are the chemically reactive groups of atoms within an organic molecule

Define functional group

Functional groups affect molecular function by being directly involved in chemical reactions

Study this figure of Stanley Miller's experiment to simulate conditions thought to have existed on the early Earth. Explain the elements of this experiment, using arrows to indicate what occurs in various parts of the apparatus.

The water mixture in the "sea" at the bottom of the flask was heated; thus vapor entered the "atmosphere" of the flask (1), containing a mixture of hydrogen gas, methane, ammonia, and water vapor (2). Sparks were discharged to mimic lightning (3). A condenser cooled the "atmosphere," raining water molecules down into the "sea" (4). As material cycled through the apparatus, Miller periodically collected samples for analysis (5)