BIOL 230W FA 2025 Chapter 1 – Introduction to the Study of Cell and Molecular Biology (Vocabulary Flashcards)

A comprehensive set of vocabulary-style flashcards covering key concepts, people, cellular theory, cell types, viruses, bacteriophages, viroids, and prions from Chapters 1–2.

Robert Hooke

Discovered cells using a rudimentary compound microscope; coined the term 'cell' because cork reminded him of monk cells.

Compound microscope (Hooke)

A rudimentary two-lens (double convex) microscope Hooke used to view cork slices.

Cork observations

Hooke observed a honeycomb-like network of chambers, leading to the term 'cells'.

Cell (definition origins)

The word 'cell' was chosen because Hooke thought cork resembled monastery cells.

Antoni van Leeuwenhoek

Reported protozoa (1674) and bacteria (1676); built simple microscopes with high magnification; called microorganisms animalcules.

Leeuwenhoek's simple microscope

A single-lens microscope capable of magnifying objects over 200x; first to observe microorganisms.

Animalcules

Term used by Leeuwenhoek to describe microorganisms.

Cell Theory Tenet 1

All organisms are composed of one or more cells.

Cell Theory Tenet 2

The cell is the structural unit of life (fundamental building block).

Cell Theory Tenet 3

Cells arise only by division of pre-existing cells.

Schleiden

Concluded that plant tissues are made of cells.

Schwann

Proposed the first two tenets of cell theory; noted similarity between plant and animal cellular basis; early views allowed spontaneous generation.

Spontaneous generation

Idea that life arises from noncellular materials; disproved by Pasteur.

Virchow

Added the third tenet of cell theory: cells arise from pre-existing cells.

Prokaryotes vs. Eukaryotes

Distinguished by internal structure and size; prokaryotes are structurally simpler; eukaryotes are more complex.

Genetic code in prokaryotes and eukaryotes

Both use DNA with an identical genetic code (double-stranded DNA).

Shared metabolic pathways (prokaryotes & eukaryotes)

Both use common pathways (e.g., glycolysis, TCA cycle) for energy metabolism.

Shared structural features

Both have a plasma membrane with similar architecture.

Transcription/translation machinery

Both use ribosomes; mechanisms of transcription and translation are conserved enough to allow cross-species DNA manipulation.

ATP synthesis & photosynthesis similarities

Conserved ATP synthase; cyanobacteria and green plants share photosynthetic mechanisms.

Nucleus (eukaryotes)

Membrane-bound organelle that houses linear DNA; separates nucleus from cytoplasm; contains organelles.

Nucleoid (prokaryotes)

Region in the cytoplasm containing a single DNA molecule; not membrane-bound.

Archaea

Domain of prokaryotes; closest relatives to eukaryotes; often extremophiles.

Methanogens

Archaea that convert CO2 and H2 into methane (CH4).

Halophiles

Archaea that thrive in extremely salty environments.

Acidophiles

Archaea that prefer acidic conditions.

Thermophiles

Archaea that live at very high temperatures.

Bacteria (domain)

Prokaryotic domain found in virtually all habitats; cyanobacteria are notable for photosynthesis and nitrogen fixation.

Cyanobacteria

Complex prokaryotes with elaborate cytoplasmic membranes for photosynthesis and capable of nitrogen fixation.

Escherichia coli (E. coli)

A widely used model bacterium; example of bacteria.

Staphylococcus aureus

A common gram-positive bacterial pathogen.

Virus (viruses)

Obligate intracellular parasites; require a host cell to reproduce; must have a genome.

Virion

A virus particle outside a host cell; genome enclosed by a protein capsid.

Viral genomes

Virus genomes can be dsDNA, ssDNA, dsRNA, or ssRNA.

Capsid

Protein shell surrounding the virion.

Capsomere

Subunit building blocks that compose the capsid.

Nucleocapsid

Genome plus its capsid.

Bacteriophages

Viruses that infect bacteria; among the most complex viruses.

Lytic cycle

Viral replication cycle that ends with host cell lysis and release of progeny virions.

Lysogeny

A phage lifecycle where the phage genome integrates as a prophage and remains dormant until induction.

Prophage

Dormant phage genome integrated into the bacterial chromosome.

Induction

Activation of a prophage leading to excision and entry into the lytic cycle.

Attachment (T4 phage)

Initial binding of the phage to the host cell.

Entry (T4 phage)

Viral genome entry; injection into the cytoplasm; lysozyme assists by weakening the cell wall.

Synthesis (phage)

Host machinery used to synthesize viral components.

Assembly (phage)

Virions spontaneously assemble inside the host.

Release (phage)

Virions exit the host cell, often via lysis.

Lysozyme

Enzyme that degrades peptidoglycan in bacterial cell walls; aids entry and release of phages.

Virulent phages

Phages that strictly follow the lytic cycle.

Temperate phages

Phages that can undergo lysogenic (temperate) lifecycle.

Temporate phages

Alternate spelling for temperate phages; capable of lysogeny.

Prophage induction

Prophage excision triggering entry into the lytic cycle.

Viroids

Extremely small circular ssRNA molecules infectious in plants; lack capsids and do not encode proteins.

Viroids vs RNA viruses

Viroids lack capsids and protein-coding capacity; RNA viruses have capsids and encode proteins.

Viroid disease mechanism

RNA sequences bind complementary plant mRNA, forming dsRNA-like structures and triggering disease.

Stunting (viroid disease)

Growth retardation in plants due to viroid infection.

Prions

Proteinaceous infectious particles that cause disease.

PrP (prion protein)

Mammalian brain cell membrane protein.

Cellular PrP (c-PrP)

Normal prion protein; rich in alpha-helices; physiological role not fully understood.

Prion PrP (p-PrP)

Disease-causing form; rich in beta-pleated sheets.

Templating

Process by which p-PrP induces refolding of normal c-PrP into the prion form.

Prion diseases (spongiform encephalopathies)

Fatal neurodegenerative diseases with brain vacuolation, giving a sponge-like appearance; e.g., mad cow disease.

Mammalian PrP localization

PrP is found in mammalian brain cell membranes.