Chapter 1: Introduction to the Chemistry of Life

The origins of life using the primordial atmosphere theory

Suggests that the atmosphere consisted of N, H2O, CH4, H2, CO2, and NH3. It is believed UV radiation from the sun or lighting discharge caused a reaction to form organic compounds.

Abiogenesis

Living organisms originating from inorganic materials.

The major elements in most biological compounds

include carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

Miller-Urey Experiment

Conducted by Stanley Miller and Harold Urey, the experiment used a closed system that simulated what scientists thought the early Earth environment might have been like.

Miller-Urey Experiment breakthrough

demonstrated that organic compounds can form from inorganic precursors under early Earth-like conditions.

enhancement of chemical versatility of simple organic molecules

Combining different monomers and their functional groups into a single large molecule

condensation

two molecules combine to form a larger molecule, with the release of water (e.g. forming a peptide bond)

hydrolysis

a larger molecule is broken down in smaller molecules with the addition of water (e.g. breaking peptide bond)

evolution of self-replicating systems

simple pairing began between complementary functional groups. This allows one member of a pair to determine the identity and orientation of the other member. (ex. DNA synthesis)

complementarity

the principle that certain molecules or parts of molecules can pair or interact with each other in a way that is specific. This makes it possible for a macromolecule to replicate, or copy itself using an existing template

compartmentation

the organization of biological processes into specific, distinct spaces within a cell or tissue, often bounded by membranes or other structures

benefits of compartmentation

(1) Protection from adverse environmental forces.

(2) Allows for maintenance of high local concentrations of biological molecules.

(3) Each organelle can maintain unique internal conditions, such as pH, ion concentrations, and enzyme composition.

endosymbiotic theory

smaller organisms (ex. bacteria) may have been engulfed by larger ones, forming a mutually beneficial relationship. This is believed to be how organelles such as the mitochondria and chloroplasts originated.

evolution of life from unicellular organisms

some cells began to specialize in function, eventually leading to the formation of multicellular organisms with differentiated tissues. This process was slow and gradual.

role of energy in natural selection

natural selection favored organisms that developed high energy generating metabolic pathways from simpler and abundant precursors (ex. photosynthesis).

eukaryotes characteristics

(1) plants, animals, fungi, protozoans, yeasts, and some algae.

(2) larger cells

(3) plasma membrane

(4) contain internal membranes and compartments (organelles)

(5) compartmentation

prokaryotes characteristics

(1) varies and highly adaptable metabolisms

(2) fast growth rate

(3) small cells

(4) 3 basic shapes: spheroidal (cocci), rodlike (bacilli), and helically coiled (spirilla)

(5) no specific compartmentation

cytoplasm/cytosol

jelly-like substance that fills the inside of a cell, surrounding organelles. Cytosol is cytoplasm minus the organelles

nucleus

site of DNA and RNA synthesis

cytoskeleton

cell and shape mobility

endoplasmic reticulum (ER)

site of protein synthesis

lysosomes

degrade polymers into monomers

golgi apparatus

site of protein modification

mitochondria

site of oxidative energy production