Cell Biology and Virology Lecture Notes Flashcards

A comprehensive set of vocabulary flashcards covering cell organelles, cell theories (Endosymbiotic and Autogenous), cell differentiation, bacterial structures, and viral replication cycles based on the lecture notes.

Cell

The fundamental structural, functional, and biological unit of all living organisms, often called the "building blocks of life."

Nucleus

The organelle that contains the DNA of the cell; often referred to as the brain of the cell.

Nucleolus

The inner part of the nucleus that begins the assembly of ribosomes.

Chloroplast

Organelle that captures energy from light for photosynthesis; often called the solar panels of the cell.

Golgi Body/Apparatus

Organelle that modifies, sorts, and ships proteins and lipids; known as the post office of the cell.

Mitochondria

The organelle responsible for making $ATP$ (energy), known as the powerhouse of the cell.

Ribosome

Organelle that creates polypeptide chains and proteins; described as the factory of the cell.

Smooth Endoplasmic Reticulum

Organelle that creates lipids for the cellular membrane.

Rough Endoplasmic Reticulum

Organelle where proteins are assembled and transported into/out of the cell; covered with ribosomes.

Lysosome

A membranous sac containing enzymes used to break down old organelles and macromolecules; the garbage disposal of the cell.

Vacuole

Sac-like structure that stores water, salts, and carbohydrates; the kitchen of the cell.

Cytoskeleton

A network of thin protein fibers that help the cell maintain its shape and are involved in movement.

Cytoplasm

The jelly-like material inside the cell membrane but outside of the nucleus that fills the cell.

Centriole

Organelle that helps organize cell division; present in animal cells but absent in plant cells.

Cell Wall

A rigid outer structure found in plant, fungi, and some bacteria cells that provides stability and support.

Cell Membrane

A selectively permeable phospholipid bilayer that surrounds all cells and controls what enters and exits.

Prokaryotic Cells

Small ($0.1$ to $5.0 \text{ μm}$), simple, unicellular organisms that lack a nucleus and membrane-bound organelles, such as bacteria and archaea.

Eukaryotic Cells

Large ($10$ to $100 \text{ μm}$) and complex cells that contain a nucleus and membrane-bound organelles; includes plant and animal cells.

Binary Fission

A form of asexual reproduction and cell division used by prokaryotic cells.

Endosymbiotic Theory

The theory that complex eukaryotic cells evolved from a symbiotic relationship where simplified prokaryotes, like mitochondria and chloroplasts, were engulfed by larger host cells.

70S Ribosomes

The specific size of ribosomes found in mitochondria and chloroplasts, which supports the theory that they originated from bacteria.

Autogenous Theory

The theory suggesting eukaryotic cells evolved from a single prokaryotic ancestor through internal modifications like membrane infolding.

Tissue (Adult) Stem Cells

Multipotent cells found in mature organisms whose function is to replenish differentiated cells within their particular tissue type.

Embryonic Stem Cells

Pluripotent cells found in early embryos that can give rise to all types of cells in the body.

Cell Differentiation

The process controlled by gene expression through which a cell becomes specialized to perform specific tasks.

Nucleoid

An irregularly shaped region in a bacteria cell where the genetic material floats freely because there is no nuclear membrane.

Plasmids

Small, extra rings of circular DNA in bacteria that often carry traits like antibiotic resistance.

Capsule

A sticky, outer layer found on some bacteria that helps them stick to surfaces and protects them from destruction.

Virus

A submicroscopic, infectious particle consisting of DNA or RNA covered by a protein coat (capsid) that can only replicate inside a living host cell.

Virion

A complete, functional virus particle existing outside of a host cell.

Bacteriophage

A type of virus that infects and replicates exclusively within bacteria; literally translates to "bacteria eater."

Lytic Cycle

A viral replication cycle that ends with the host cell rupturing (lysis) to release new viral particles.

Lysogenic Cycle

A viral replication cycle where the virus integrates its DNA into the host genome and replicates silently along with the host cell until triggered to enter the lytic cycle.

Retrovirus

A type of virus, such as HIV, that contains RNA instead of DNA.

Viroid

An exceptionally small, subviral particle made only of "naked" RNA without a protein coat; primarily infects plants.

Prions

Infectious agents consisting of misfolded proteins.

ATP (Adenosine Triphosphate)

The primary organic molecule that acts as the energy currency of all living cells.

Cellular Respiration

The process by which living cells convert glucose into energy in the form of $ATP$.

Cell Theory

The scientific theory stating all living organisms are composed of cells, the cell is the basic unit of life, and all cells come from preexisting cells.