01.03 and 01.03A Earth's Early Atmosphere

describe the conditions on Earth billions of years ago, summarize theories of how life began on Earth, describe the relationship between organic compounds, nucleotides, RNA, and a universal genetic code, explain the connection between the beginning of life and the universal genetic code of almost all organisms.

organic molecules

carbon-based molecules.

UV radiation

nonviable waves of energy contained in the energy that travels from the Sun to the Earth

nucleotides

the building blocks for DNA/RNA

vesicles

a small fluid-filled or air-filled sac or cavity that are hypothesized to be the precursors to modern-day cells.

DNA

genetic material with instruction used in the development of living things.

RNA

ribonucleic acid is a macromolecule made up of nucleotides that is essential for all known forms of life.

RNA world hypothesis

organic molecules could have formed spontaneously in Earth’s early atmosphere, and smaller molecules could bond together to build large organic molecules with the first large organic molecules to form and self-replicate being RNA molecules.

catalyst

a substance the increases the rate of chemical reaction without itself undergoing any permanent chemical change.

microspheres

tiny bubbles filled with groups of large organic molecules formed under very specific conditions.

acetate

an organic molecule that plays important roles in living cells.

pyruvate

an organic acid that serves and important role in several metabolic pathways

anaerobic respiration

a chemical process that allows cells to get energy from organic molecules like carbohydrate glucose when there is no oxygen gas present.

autotrophic organisms

things that take in inorganic molecules and transform them into organic nourishment, using light or chemical energy in the process. They are the primary produces at the base of all food chains.

photoautotrophs

use light energy from the sun to convert carbon dioxide and other simple inorganic molecules to organic compounds that could be used for energy through a process known as photosynthesis

photosynthesis

light energy + 6H2O + 6CO2 → C6H12O6 + 6O2

chemoautotrophs

organisms that use chemical energy from source such as deep-sea vents to convert inorganic compounds into organic compounds in a process called chemosynthesis.

chemosynthesis

chemical energy + 6CO2 + 6H2O + 3H2S → C6H12O6 + 3H2SO4

methanogens

single celled organisms that produce methane (CH4) in a form of anaerobic respiration. Common in wetlands, marine sediments, and guts of many animals.

thermophiles

single-celled organisms that live in extremely high temperatures and can be found in hot springs and deep-sea vents

halophiles

organisms that thrive in environments with very high concentration of salt. Many conduct photosynthesis and can be found in place with salt concentrations 5x greater than the ocean.

cyanobacteria

photosynthetic prokaryotes that live in the water. Most abundant bacteria on the planet and release large amounts of oxygen into the atmosphere. grow in colonies and can be located with the naked eye.