biogeochemical cycles

Biosphere, Lithosphere, Hydrosphere, Atmosphere

Earth’s Spheres

Lithosphere

the solid (or molten) Earth

Hydrosphere

liquid Earth (cryosphere is the frozen Earth)

Element

a substance that cannot be broken down into simpler substances by chemical means; same number of PROTONS in nucleus, so same ATOMIC NUMBER

Isotope

Atoms of an element with different numbers of neutrons (and hence different atomic masses); some are radioactive

Different isotopes of an element will behave very similarly but have crucial

differences in fractionation and chemical reaction rates

Are isotopes of the same element similar or different? How?

Ion

Electrically charged (positive or negative) molecules or atom

Carbon

basic building block of organic molecules, 4 bonds

Hydrogen

Smallest and most abundant element, fills out organic molecules because it only needs one bond

Oxygen

Two bonds – Strong oxidizer (really wants to steal electrons)

Nitrogen

3 bonds – key element in protein structure

Phosphorus

Key element in cellular energy (ATP) and in DNA

Sulfur

Important component in amino acids (proteins)

Calcium

Mineral that serves a structural role

Iron

Used in proteins, often for transferring electrons

Covalent bonds

strong bonds formed by sharing of electrons; can be equal sharing (nonpolar) or unequal sharing (polar)

Ionic bonds

Strong bonds formed when one atom transfers its electrons to another; The two ions (positive and negative) are then strongly attracted to each other

Dipole (hydrogen) bonds

Weak bonds formed between polar molecules

Water molecule

Can break apart into OH- (hydroxide) and H+ (hydrogen) ions. Neutral is pH of 7.

Acidity

in water; refers to the relative balance of H+ and OH- (high H+ is acidic)

Organic Molecules

Made of carbon atoms covalently bonded to other carbon atoms or hydrogen, nitrogen, oxygen, and other elements; the primary structural and functional elements of

organisms

Carbohydrates, lipids (fats), proteins, nucleic

acids (DNA), hydrocarbons

Organic molecules include

Inorganic Molecules

molecules without carbon-carbon bonds

Carbohydrates

Carbon, hydrogen, and oxygen; includes sugars like glucose

Lipids (fats & oils)

Long chains of carbon and hydrogen, and a short region with one or more oxygen atoms; form most cellular membranes and also used as energy storage

Hydrocarbons

organic molecules comprised entirely of Carbon & Hydrogen; Includes methane, ethane, propane, etc.

Macromolecules

combinations of small organic molecules

Polysaccharides

polymers (chains) of simple sugars (e.g. starch & cellulose)

Proteins

polymers of amino acids (nitrogen-containing organic molecules); there are 20 different amino acids, 100-1000 amino acids linked in a chain. Fold in on themselves into complex three-dimensional structures and mediate most of the organism’s functions

Nucleic acids

polymers of nucleotides

Nucleotides

small molecules that contain a 5-C sugar, a phosphate (PO4) group, and a nitrogenous base

DNA

a nucleic acid formed of 4 nucleotides (A,T,G,C)

prokaryotes; fermentation

The earliest forms of life on Earth were ____ that got their energy from _____

low; alcohol and CO2

Fermentation has a ____ energy yield and gives off ______ and ____ as waste products

Prokaryote

single-celled organisms that lack cellular organelles (nucleus, mitochondria, etc.); bacteria and archaebacteria, including cyanobacteria

Cyanobacteria

led to the rise of oxygen

Eukaryotes

Organisms that have membrane-enclosed structures in their cells (e.g. nucleus, mitochondria, chloroplast); include protists, fungi, plants, animals.

True

T/F: Biogeochemical cycles often involve organisms interacting with the abiotic (non-living) portion of their environment

Rocks and Soil

Continually created, maintained, changed and destroyed over the last 4.6

billion years due to physical, chemical, and biological processes

Tectonic, Hydrologic, Rock, Biogeochemical

Geologic cycles

Tectonic Geological Cycles

formation of mountains, continents, etc.

Rock Geologic Cycles

Weathering

Gravity pulled heavy materials to center, creating a dense core (nickel & iron) with high pressure then a lesser dense mantle and a lighter rocky crust

How did Earth become formed?

Continental crust is the thickest. Oceanic crust is the densest

Is oceanic or continental crust more thick? Which one is more dense?

Plate tectonics

By Alfred Wegner; Earth’s crust is broken into different plates that float on top of mantle and their movement is driven by convection currents in the upper mantle.

Plate Boundaries

areas where plates come together

The Hydrologic Cycle

The transfer of water from oceans to the atmosphere to the land and back

to the oceans; driven by solar energy

Precipitation above a watershed directly affects water levels throughout that watershed; Water flows in the watershed transport nutrients (and pollutants) across the watershed

Why do we care about watersheds?

Catchments

small drainage basins within a larger watershed

True

T/F: Water falling outside of the watershed will not be transported into the watershed