Foundations of Life and Cell Cycle Reviewer Flashcards

Vocabulary flashcards covering cellular organelles, scientists and discoveries in cell theory, cell cycle phases and checkpoints, and DNA repair mechanisms based on the Biology 1 Summative Exam Reviewer.

Cell Membrane

Selectively permeable outer boundary of the cell that regulates the movement of glucose, ions, and other molecules into and out of the cell.

Cytoplasm

Gel-like internal fluid environment consisting of cytosol and suspended organelles, serving as the medium where most metabolic reactions take place.

Mitochondria

Organelles known as the powerhouses of the cell that carry out aerobic cellular respiration to generate ATP required for cell function.

Ribosomes

Cellular structures responsible for protein synthesis (translation), located freely floating in the cytoplasm or attached to the Rough ER.

Rough Endoplasmic Reticulum

Membrane-bound network studded with ribosomes responsible for synthesizing, folding, and initiating transport of proteins destined for secretion or other organelles.

Smooth Endoplasmic Reticulum

Membrane-bound network lacking ribosomes that synthesizes lipids and steroids, and detoxifies drugs, poisons, and harmful chemicals.

Golgi Body

Organelle that modifies, sorts, packages, and ships proteins and lipids received from the endoplasmic reticulum to their final destinations via secretory vesicles.

Lysosomes

Membrane-bound organelles containing hydrolytic digestive enzymes that break down waste materials, cellular debris, and worn-out organelles.

Centrioles

Cylindrical structures that organize mitotic spindle fibers to pull sister chromatids apart during cell division.

Nucleus

Membrane-bound structure containing the cell's genetic material (DNA); acts as the command center controlling cellular activities, heredity, and gene expression.

Nucleolus

Dense region inside the nucleus responsible for producing ribosomal RNA (rRNA) and assembling ribosomal subunits.

Cytoskeleton

Network of protein filaments that provides cell shape, structural support, and pathways for intracellular transport and movement.

Vesicle

Small membrane-bound sac used to store or transport materials within the cell.

Peroxisome

Organelle responsible for cellular metabolic functions, specifically involved in synthesizing hydrogen peroxide.

Matthias Schleiden

Botanist who concluded that all plant tissues are composed of cells, contributing to the establishment of modern cell theory.

Robert Hooke

Scientist who first discovered and named 'cells' in 1665 after observing box-like structures in cork tissue under a microscope.

Robert Brown

Scientist who identified and described the nucleus as a consistent sub-cellular component inside plant cells.

Rudolf Virchow

Scientist who established the principle omnis cellula e cellula, stating that all cells arise from pre-existing cells through cell division.

Zacharias Janssen

Dutch spectacle-maker credited with constructing one of the earliest compound microscopes, initiating microscopic cellular discovery.

Louis Pasteur

Scientist who disproved spontaneous generation and demonstrated biogenesis through his swan-neck flask experiment.

Anton Van Leeuwenhoek

Microscopist who built high-powered simple microscopes and was the first to observe living microorganisms ('animalcules'), including bacteria, protists, and blood cells.

Theodore Schwann

Zoologist who determined that all animal tissues are composed of cells, co-formulating cell theory with Schleiden.

Aristotle

Ancient philosopher who proposed the concept of spontaneous generation, suggesting living organisms could arise from non-living matter.

Oil Immersion Objective ($100\times$)

Compound microscope objective lens providing the highest magnification and resolution by matching the refractive index of glass to reduce light scattering.

Binary Fission

Asexual reproduction process in prokaryotes (bacteria) where a cell splits into two identical cells without forming a mitotic spindle.

G1 Phase

First growth phase of interphase where the cell increases in size, synthesizes proteins and RNA, duplicates organelles, and passes the G1 checkpoint before DNA synthesis.

S Phase

Synthesis phase of interphase in which the cell replicates its entire DNA content, forming identical sister chromatids.

G2 Phase

Second growth phase of interphase where the cell produces proteins needed for mitosis (such as tubulin) and verifies DNA replication completeness.

Metaphase Checkpoint

Spindle assembly checkpoint ensuring all chromosomes align at the equatorial plate and kinetochores correctly attach to spindle fibers before anaphase.

Telophase

Final stage of mitosis where chromosomes decondense into chromatin, nuclear envelopes reform around daughter nuclei, and spindle fibers break down.

p53 (TP53)

Tumor suppressor gene/protein that halts the cell cycle at the G1/S checkpoint to allow DNA repair or trigger apoptosis if damage is irreparable.

Base Excision Repair (BER)

DNA repair pathway primarily responsible for correcting small, chemically modified lesions, such as oxidized guanine bases.

Homologous Recombination (HR)

Precise DNA repair mechanism that uses a sister chromatid template to accurately repair double-strand DNA breaks.

Non-Homologous End Joining (NHEJ)

Fast but error-prone DNA repair mechanism that directly joins broken DNA ends without requiring a homologous template.

DNA Ligase

Enzyme catalyzing the final sealing step of DNA repair and replication by forming phosphodiester bonds in the sugar-phosphate backbone.