Biomolecules and Cells Study Guide (Week 1)

Vocabulary flashcards covering basic chemistry, biomolecules, cell structures, and eukaryotic evolution concepts from Week 1.

Atom

The basic unit of matter consisting of a dense central nucleus surrounded by electrons.

Proton

A positively charged subatomic particle found within the nucleus of an atom.

Electron

A negatively charged subatomic particle that orbits around the atomic nucleus.

Neutron

A subatomic particle found within the atomic nucleus that carries no electrical charge.

Molecule

A group of two or more atoms held together by chemical bonds.

Ion

An atom or group of atoms that has gained or lost one or more electrons, acquiring a net electric charge.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Covalent Bond (Nonpolar)

A chemical bond formed when two atoms share electrons equally between them.

Polar Covalent Bond

A chemical bond in which electrons are shared unequally between atoms, creating partial positive and negative charges.

Hydrogen Bond

A weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Ionic Bond

A chemical bond resulting from the electrostatic attraction between oppositely charged ions created by electron transfer.

Van der Waal Forces

Weak, distance-dependent electrostatic interactions or attractions between uncharged atoms or molecules.

Hydrophobic Interaction

The tendency of nonpolar molecules to aggregate together in aqueous solutions to minimize contact with water.

Dehydration Reaction

A chemical reaction that links monomers together to form a polymer, releasing a molecule of water in the process.

Hydrolysis Reaction

A chemical reaction that breaks bonds within polymers into monomers through the addition of a water molecule.

Solute

A substance that is dissolved in a solvent to form a solution.

Solvent

The liquid capable of dissolving other substances (solutes) to form a solution.

Chemical Reaction

A process that involves rearrangement of the molecular or ionic structure of a substance.

Hydrophilic

Having an affinity for water; typical of polar or charged molecules that readily interact with or dissolve in water.

Hydrophobic

Lacking affinity for water; typical of nonpolar molecules that do not dissolve in or interact favorably with water.

Carbohydrate

A biological macromolecule made of monosaccharide units that functions in energy storage and structural support.

Lipid

A diverse group of nonpolar biological molecules, including fats and phospholipids, essential for membranes and energy storage.

Protein

A biological macromolecule composed of amino acid polymers that carries out diverse cellular structures and functions.

Nucleic Acid

A biological macromolecule composed of nucleotide chains, such as DNA or RNA, that stores and transmits genetic material.

Monosaccharide

The simplest single-sugar monomer building block of carbohydrates.

Polysaccharide

A complex polymer composed of many monosaccharide units bonded together.

Prokaryotic Cell

A simple cellular organism lacking a membrane-bound nucleus and membrane-bound organelles.

Eukaryotic Cell

A complex cell containing a membrane-bound nucleus and specialized membrane-bound organelles.

Cell Wall

A rigid outer structure surrounding the cell membrane in plant cells and prokaryotes that provides structure and support.

Cell Membrane

A flexible, encapsulating phospholipid bilayer that controls the passage of substances into and out of the cell.

Organelle

A specialized membrane-bound subunit within a eukaryotic cell that performs a specific biological function.

Nucleus

The membrane-bound eukaryotic organelle that encloses and protects the cell's genetic material (DNA).

Mitochondria

The membrane-bound eukaryotic organelles responsible for cellular respiration and generating energy (ATP).

Endoplasmic Reticulum

A eukaryotic membrane network involved in the synthesis, processing, and transport of proteins and lipids.

Golgi Apparatus

An organelle in eukaryotic cells that modifies, sorts, and packages proteins and lipids for transport.

Chloroplast

A membrane-bound organelle found in plant cells that carries out photosynthesis to convert light energy into chemical energy.

Endosymbiotic Theory

The evolutionary theory stating that eukaryotic organelles such as mitochondria and chloroplasts originated from symbiotic prokaryotic cells.