cell bio exam 1 learning objectives

Endosymbiotic theory

A hypothesis that explains how organelles in eukaryotic cells evolved from prokaryotic cells through a process called symbiosis, where one organism lives inside another.

Cell theory

A principle stating that all living cells are formed from preexisting cells and that all organisms are composed of one or more cells.

Prokaryotic cells

Cells that lack a nucleus and membrane-bound organelles, generally smaller and unicellular.

Eukaryotic cells

Cells that contain a nucleus and membrane-bound organelles, generally larger and can be unicellular or multicellular.

Covalent bonds

Chemical bonds formed by the sharing of electrons between atoms.

Polar covalent bonds

Covalent bonds where electrons are shared unequally due to differences in electronegativity.

Hydrogen bonds

Weak bonds formed when a hydrogen atom covalently bonded to a highly electronegative atom is attracted to another electronegative atom.

Hydrophobic interactions

Interactions that occur between nonpolar molecules in an aqueous environment, causing them to aggregate.

Hydrophilic

Substances that readily dissolve in water, often due to the presence of polar covalent bonds.

Amphipathic molecules

Molecules that contain both hydrophilic and hydrophobic parts.

Nucleus

The membrane-bound organelle in eukaryotic cells that contains DNA.

Ribosomes

Cellular structures responsible for protein synthesis.

Mitochondria

Organelles in eukaryotic cells where oxidative phosphorylation occurs, producing ATP.

Chloroplasts

Organelles in plant and algal cells containing chlorophyll, the site of photosynthesis.

Cytosol

The semi-fluid substance that makes up the majority of the cytoplasm, where many chemical reactions occur.

Plasma membrane

The lipid bilayer that surrounds living cells, controlling the movement of substances in and out.

Cytoskeleton

A network of protein filaments in the cytoplasm that provides structural support and facilitates cell movement.

Lysosome

An organelle that contains digestive enzymes to break down waste materials and cellular debris.

Golgi apparatus

An organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Cell wall

A rigid layer that provides structural support and protection to plant cells.

Electrostatic interactions

Forces between charged molecules that affect their behavior in cells.

Van der Waals attractions

Weak, non-specific forces between molecules due to temporary fluctuations in electron distribution.