Ch.04Carbon and the Molecular Diversity of Life

Home , Carbonyl group, Functional group, Ketone, Methyl group

EXPERIMENT “Atmosphere”

CH4 Water vapor Electrode Molecular Structural Ball-and-Stick Space-Filling Name Formula Formula Model Model NH 3 H 2 (a) Methane

Condenser

Cooled water (b) Ethane containing Cold organic water molecules

H2O “sea”

Sample for chemical analysis 1 2

Hydrogen Oxygen Nitrogen Carbon (valence = 1) (valence = 2) (valence = 3) (valence = 4)

H O N C

Urea

3 4

Fat droplets (stained red)

Ethane Propane 1-Butene 2-Butene (a) Length (c) Double bonds

Butane 2-Methylpropane (commonly called isobutane) Cyclohexane Benzene (b) Branching (d) Rings 100 µm (a) Mammalian adipose cells (b) A fat molecule

5 6 Effective Ineffective Drug Condition Pentane 2-methyl butane Enantiomer Enantiomer

(a) Structural isomers

Ibuprofen Pain; inflammation

cis isomer: The two Xs are trans isomer: The two Xs are S-Ibuprofen R-Ibuprofen on the same side. on opposite sides.

(b) Geometric isomers

Albuterol Asthma

R-Albuterol S-Albuterol

L isomer D isomer (c) Enantiomers 7 8

Estradiol

Testosterone

L-dopa D-dopa

9 10

CHEMICAL Hydroxyl Carbonyl Carboxyl CHEMICAL Amino Sulfhydryl Phosphate Methyl GROUP GROUP

(may be STRUCTURE STRUCTURE written HS—)

(may be written HO—) The amino group The sulfhydryl group In a phosphate group, a A methyl group consists of a In a hydroxyl group (—OH), a The carbonyl group ( CO) When an oxygen atom is (—NH2) consists of a consists of a sulfur atom phosphorus atom is bonded to carbon bonded to three hydrogen atom is bonded to an consists of a carbon atom double-bonded to a carbon nitrogen atom bonded bonded to an atom of four oxygen atoms; one oxygen hydrogen atoms. The methyl oxygen atom, which in turn is joined to an oxygen atom by a atom that is also bonded to to two hydrogen atoms hydrogen; resembles a is bonded to the carbon skeleton; group may be attached to a and to the carbon hydroxyl group in shape. two oxygens carry negative carbon or to a different atom. bonded to the carbon skeleton of double bond. an —OH group, the entire skeleton. charges. The phosphate group the organic molecule. (Do not assembly of atoms is called 2– (—OPO3 , abbreviated P ) is an confuse this functional group a carboxyl group (—COOH). ionized form of a phosphoric acid – 2 with the hydroxide ion, OH .) group (—OPO3H ; note the two hydrogens).

NAME OF Alcohols (their specific names Ketones if the carbonyl group is Carboxylic acids, or organic NAME OF Amines Thiols Organic phosphates Methylated compounds COMPOUND usually end in -ol) within a carbon skeleton acids COMPOUND Aldehydes if the carbonyl group is at the end of the carbon skeleton

EXAMPLE EXAMPLE

Glycine Glycerol phosphate Ethanol, the alcohol present in Acetone, the simplest ketone Acetic acid, which gives vinegar Because it also has a Cysteine alcoholic beverages its sour taste In addition to taking part in carboxyl group, glycine many important chemical 5-Methyl cytidine is both an amine and Cysteine is an important reactions in cells, glycerol a carboxylic acid; sulfur-containing amino 5-Methyl cytidine is a compounds with both phosphate provides the acid. backbone for phospholipids, component of DNA that has groups are called been modified by addition of amino acids. the most prevalent molecules in Propanal, an aldehyde cell membranes. the methyl group.

FUNCTIONAL Is polar as a result of the A ketone and an aldehyde may Has acidic properties FUNCTIONAL Acts as a base; can Two sulfhydryl groups Contributes negative charge Addition of a methyl group PROPERTIES electrons spending more time be structural isomers with because the covalent bond PROPERTIES pick up an H+ from can react, forming a to the molecule of which it is to DNA, or to molecules near the electronegative different properties, as is the between oxygen and hydrogen the surrounding covalent bond. This a part (2– when at the end of bound to DNA, affects oxygen atom. case for acetone and propanal. is so polar; for example, solution (water, in “cross-linking” helps a molecule; 1– when located expression of genes. living organisms). stabilize protein internally in a chain of Can form hydrogen bonds with These two groups are also structure. phosphates). Arrangement of methyl water molecules, helping found in sugars, giving rise to groups in male and female dissolve organic compounds two major groups of sugars: Cross-linking of Has the potential to react sex hormones affects such as sugars. aldoses (containing an cysteines in hair with water, releasing energy. their shape and function. aldehyde) and ketoses proteins maintains the (containing a ketone). curliness or straightness Acetic acid Acetate ion (nonionized) (ionized) of hair. Straight hair can be “permanently” curled Found in cells in the ionized Ionized, with a by shaping it around form with a charge of 1– and charge of 1+, under curlers, then breaking called a carboxylate ion (here, cellular conditions. and re-forming the specifically, the acetate ion). cross-linking bonds.

11 12 Reacts with H2O

P P P Adenosine P i P P Adenosine Energy ATP Inorganic ADP phosphate