General Biology II - Lecture 1: What is Life?

Vocabulary flashcards covering the essential elements of life, macromolecules, endosymbiotic evolution, key evolutionary events, and extremophile classifications from General Biology II Lecture 1.

CHNOPS

The acronym representing the six essential chemical elements required for life to exist as we know it: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.

Organic Carbon

Carbon-containing molecules that must possess C-H bonds to be classified as organic.

Hydrogen (in essential life elements)

One of the essential elements for life that forms water and is bound to many atoms in biological molecules.

Nitrogen (in essential life elements)

An essential element that forms many carbon-based ring structures and amino acids.

Oxygen (in essential life elements)

An essential element necessary for water, complex sugars, and alcohols.

Phosphorus (in essential life elements)

An essential element required for cellular energy molecules ($\text{ATP}/\text{ADP}$) and nucleic acids in DNA.

Sulfur (in essential life elements)

An essential element found in specific amino acids, such as cysteine, which contributes to protein structure.

Polypeptides

Complex biological molecules formed by chains of amino acids that make up proteins.

L.U.C.A.

Last Universal Common Ancestor, the common ancestral organism from which Bacteria, Archaea, and Eukaryota evolved.

Endosymbiont

A cell living inside another cell, such as an aerobic proteobacterium or cyanobacterium that was integrated into an early eukaryote.

Abiogenic Process

A non-biological process involved in the origin of life, with first evidence dated between $4.1$ and $3.8\,\text{billion years ago}$.

Great Oxygenation Event (GOES)

A major event in Earth's history occurring approximately $2.4\,\text{billion years ago}$ that led to a significant increase in atmospheric oxygen.

Psychrophiles

Extremophiles adapted to thrive in cold environments with temperatures below $15\,^{\circ}\text{C}$.

Thermophiles

Extremophiles adapted to thrive in high-temperature environments ranging from $50\,^{\circ}\text{C}$ to $80\,^{\circ}\text{C}$.

Hyperthermophiles

Extremophiles adapted to thrive in extremely high-temperature environments ranging from $80\,^{\circ}\text{C}$ to $115\,^{\circ}\text{C}$.

Acidophiles

Extremophiles adapted to thrive in acidic environments with pH values ranging from $4$ to $7$.

Alkaliphiles

Extremophiles adapted to thrive in basic or alkaline environments with pH values ranging from $8$ to $12.5$.

Xerophiles

Extremophiles adapted to thrive in extremely dry conditions with minimal moisture.

Tardigrade

A microscopic animal capable of surviving extreme temperatures from $1\,\text{K}$ ($-458\,^{\circ}\text{F}$; $-272\,^{\circ}\text{C}$) to $420\,\text{K}$ ($300\,^{\circ}\text{F}$; $150\,^{\circ}\text{C}$), intense pressure, high ionizing radiation, outer space vacuum, and over $30\,\text{years}$ of desiccation down to $3\%$ water content.

Endosymbiotic Origin of Eukaryotes

The evolutionary process where prokaryotic membrane infoldings formed an endomembrane system and nucleus, followed by the engulfment and assimilation of an aerobic proteobacterium (mitochondrion) and cyanobacterium (chloroplast).

General Amino Acid Structure

The molecular framework of an amino acid composed of a central carbon atom bonded to a hydrogen atom, an Amino Group, a Carboxyl Group, and a variable R Side Chain.