chapter 1 -3 bio

Fundamental Characteristics of Living Organisms

Acquire and use energy, made up of membrane-bound cells, process information, replication, and populations of organisms evolve.

Cell Theory

Cells are the fundamental unit of life, all organisms are made of cells, and all cells come from preexisting cells.

Evolution Theory

All species are related by common ancestry, and descent with modification (natural selection).

Eukaryotes

Organisms with membrane-bound nuclei, including multicellular organisms in the domain Eukarya.

Prokaryotes

Organisms without membrane-bound nuclei, including single-celled organisms in the domains Bacteria and Archaea.

Taxonomy

The naming and classifying of organisms; a taxon is a named group.

Scientific Method

A systematic approach involving observation, hypothesis, experimentation, analysis, and conclusion.

Control Group

The group in an experiment that does not receive the treatment being studied.

Four Atoms of Matter

Carbon, hydrogen, nitrogen, and oxygen make up 96% of all matter.

Protons

Positively charged particles located in the nucleus, defining the atomic number.

Neutrons

Neutral particles located in the nucleus of an atom.

Electrons

Negatively charged particles found in orbits surrounding the nucleus.

Mass Number

The sum of protons and neutrons in an atom.

Isotopes

Variants of an element with different numbers of neutrons and different atomic masses.

Valence

The outermost shell of an atom, indicating its combining power based on unpaired electrons.

Ionic Bonds

Bonds formed when electrons are transferred from one atom to another.

Covalent Bonds

Bonds formed when unpaired valence electrons are shared between atoms.

Non-Polar Covalent Bonds

Bonds with equal sharing of electrons.

Polar Covalent Bonds

Bonds with unequal sharing of electrons.

Electronegativity

The tendency of an atom to attract electrons, increasing left to right on the periodic table.

Molecular Model

Represents the type and number of atoms in a molecule.

Structural Model

Shows which atoms are bonded together and the types of bonds.

Cohesion

The attraction between like molecules.

Adhesion

The attraction between unlike molecules.

Hydrophilic Molecules

Ions and polar molecules that dissolve in water due to hydrogen bonding.

Hydrophobic Molecules

Uncharged and non-polar compounds that do not dissolve in water.

pH Scale

lower pH indicates higher acidity.

Chemical Equilibrium

A state where forward and reverse reactions occur at the same rate, maintaining constant quantities of reactants and products.

Endothermic Reaction

A reaction that absorbs heat.

Exothermic Reaction

A reaction that releases heat.

Spontaneous Reactions

Reactions that occur without added energy, resulting in products with lower potential energy and higher entropy.

Prebiotic Soup Model

Suggests that complex molecules originated from gases in the atmosphere or meteorites.

Surface Metabolism Model

Proposes that surface gases reacted with minerals near deep-sea vents to form complex molecules.

Amino Acids

Building blocks of proteins, consisting of H, NH2, COOH, and a distinctive R-group.

Peptide Bonds

Bonds formed between amino acids during condensation reactions.

Primary Structure

The unique sequence of amino acids in a protein.

Secondary Structure

Formed by hydrogen bonds, resulting in alpha helices and beta pleated sheets.

Tertiary Structure

The overall 3D shape of a protein resulting from interactions between R-groups.

Quaternary Structure

The arrangement of two or more polypeptide subunits in a protein.

Denatured Protein

A protein that has lost its functional shape.

Molecular Chaperones

Proteins that assist in the correct folding of other proteins.

Enzymes

Proteins that catalyze reactions by bringing substrates together and lowering activation energy.

acidic side chain

negative charge

basic side chain

positive charge

uncharged side chain

uncharged

non polar side chain

not charged

n terminus (peptide bond)

free amino acid on the LEFT

c terminus (peptide bond)

free carboxyl on the RIGHT

oligopeptides

fewer than 50 amino acids

polypeptides

more than 50 amino acids

hydrolysis

reverse reaction that breaks polymer’s apart by adding a water molecule

products of a spontaneous reaction

lower pe , higher entropy

reactants of a spontaneous reaction

higher pe , lower entropy