LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson © 2011 Pearson Education, Inc. Lectures by Erin Barley Kathleen Fitzpatrick Carbon and the Molecular Diversity of Life Chapter 4

Overview: Carbon: The Backbone of Life Why is carbon considered the Backbone? How does it become a part of living systems? What processes are critical to the cycle of carbon? © 2011 Pearson Education, Inc.

Figure 4.1

Concept 4.1: Organic chemistry is the study of carbon compounds CHNOPS © 2011 Pearson Education, Inc.

Organic Molecules and the Origin of Life on Earth Stanley Miller’s - abiotic synthesis of organic compounds Experiments support the idea that abiotic synthesis of organic compounds, perhaps near volcanoes, could have been a stage in the origin of life © 2011 Pearson Education, Inc.

Figure 4.2 EXPERIMENT “Atmosphere” Electrode Condenser CH 4 H2H2 NH 3 Water vapor Cooled “rain” containing organic molecules Cold water Sample for chemical analysis H 2 O “sea”

Concept 4.2: Carbon atoms can form diverse molecules by bonding to four other atoms Electron configuration – is the key to an atom’s characteristics –determines the kinds and number of bonds an atom will form with other atoms © 2011 Pearson Education, Inc.

Figure 4.3 Name and Comment Molecular Formula (a) Methane (b) Ethane CH 4 Ball-and- Stick Model Space-Filling Model (c) Ethene (ethylene) C2H6C2H6 C2H4C2H4 Structural Formula

Figure 4.4 Hydrogen (valence  1) Oxygen (valence  2) Nitrogen (valence  3) Carbon (valence  4)

Figure 4.UN01 Urea

Figure 4.5a (a) Length Ethane Propane

Figure 4.5b (b) Branching Butane 2-Methylpropane (commonly called isobutane)

Figure 4.5c 1-Butene (c) Double bond position 2-Butene

Figure 4.5d (d) Presence of rings Cyclohexane Benzene

Hydrocarbons  organic molecules consisting of only carbon and hydrogen  can undergo reactions that release a large amount of energy © 2011 Pearson Education, Inc.

Figure 4.6 Nucleus Fat droplets (b) A fat molecule(a) Part of a human adipose cell 10  m

Isomers Isomers are compounds with the same molecular formula but different structures and properties –Structural isomers have different covalent arrangements of their atoms –Cis-trans isomers (geometric) have the same covalent bonds but differ in spatial arrangements –Enantiomers are isomers that are mirror images of each other © 2011 Pearson Education, Inc.

Figure 4.7 (a) Structural isomers (b) Cis-trans isomers (c) Enantiomers cis isomer: The two Xs are on the same side. trans isomer: The two Xs are on opposite sides. CO 2 H CH 3 H NH 2 L isomer NH 2 CH 3 H D isomer

Figure 4.7a (a) Structural isomers

Figure 4.7b (b) Cis-trans isomers cis isomer: The two Xs are on the same side. trans isomer: The two Xs are on opposite sides.

Figure 4.7c (c) Enantiomers CO 2 H CH 3 H NH 2 L isomer NH 2 CH 3 H D isomer

Figure 4.8 Drug Ibuprofen Albuterol Condition Effective Enantiomer Ineffective Enantiomer Pain; inflammation Asthma S-IbuprofenR-Ibuprofen R-Albuterol S-Albuterol

The Chemical Groups Most Important in the Processes of Life Functional groups  involved in chemical reactions  The number and arrangement give each molecule its unique properties © 2011 Pearson Education, Inc.

Figure 4.UN02 Estradiol Testosterone

ATP: An Important Source of Energy for Cellular Processes One phosphate molecule, adenosine triphosphate (ATP), is the primary energy- transferring molecule in the cell ATP consists of an organic molecule called adenosine attached to a string of three phosphate groups © 2011 Pearson Education, Inc.

Figure 4. UN05 Adenosine Reacts with H 2 O Inorganic phosphate ATP ADP Energy