Cell Theory, Structures, and Cellular Processes

Comprehensive vocabulary flashcards covering the history of cell theory, organelle functions, the cell cycle, membrane structure, and transport mechanisms.

Cellula

A Latin word meaning small room, which Robert Hooke used to coin the term cell in 1665.

Micrographia

The book published by Robert Hooke in 1665 containing his observations of cork and other structures.

Animalcules

The name Antonie van Leeuwenhoek gave to the freshwater protozoans he discovered.

Matthias Schleiden

A scientist who stated in 1838 that all plants are composed of cells and noted the importance of the nucleus in producing new cells.

Theodor Schwann

A scientist who found that all animal tissues are made of cells and declared that all living things are composed of cells and cell products.

François-Vincent Raspail

The French scientist who actually first coined the phrase "Omnis cellula e cellula."

Robert Remak

The German scientist who first discovered that the origin of cells is by the division of preexisting cells.

Postulate 1 (Cell Theory)

All living things are made of at least one cell.

Postulate 2 (Cell Theory)

Cells are the basic unit of life.

Postulate 3 (Cell Theory)

All cells come from preexisting cells.

Nucleus

The control center of the cell that acts as a genetic library and membrane-bound store for genetic information.

Nucleolus

A structure within the nucleoplasm containing RNA, proteins, and DNA, responsible for ribosome synthesis.

Nucleoplasm

A gel-like substance within the nucleus with a higher concentration of proteins and macromolecules compared to cytoplasm.

Cytosol

The fluid component of the cytoplasm that fills the space between organelles and the cell membrane.

Cytoplasm

Includes the cytosol and all organelles within the cell membrane; provides a medium for chemical reactions.

Chromatin

The complex of DNA and proteins (primarily histones) that make up the genetic material in the nucleus.

Rough Endoplasmic Reticulum

A portion of the ER containing ribosomes on its surface involved in protein synthesis.

Smooth Endoplasmic Reticulum

A portion of the ER lacking ribosomes, involved in lipid and steroid synthesis, carbohydrate metabolism, and calcium storage.

Ribosomes

Cellular structures responsible for translating genetic code from mRNA into specific sequences of amino acids to form polypeptide chains.

Golgi apparatus

A processing and packaging center that modifies, sorts, and packages proteins and lipids for transport.

Mitochondria

The powerhouse of the cell and site of cellular respiration, generating energy in the form of $ATP$.

Peroxisomes

Organelles that use oxidative enzymes to remove hydrogen atoms from substrates, producing hydrogen peroxide as a byproduct.

Lysosome

An animal cell organelle containing hydrolytic enzymes used for cellular digestion and recycling worn-out organelles.

Centrosomes

The primary microtubule-organizing center in animal cells containing two barrel-shaped centrioles.

Chloroplasts

Specialized plant organelles where photosynthesis occurs, containing the light-absorbing pigment chlorophyll.

Cell wall

A rigid outer layer in plant cells primarily composed of cellulose that provides structural support and protection.

Microvilli

Finger-like structural modifications that increase the surface area of cells for enhanced nutrient absorption in the small intestine.

Plasmodesmata

A channel through the plant cell wall allowing molecules to move between neighboring cells.

Chromatophores

Specialized pigment-containing cells that allow animals like fish, amphibians, and cephalopods to change color.

Nematocysts

Stinging organelles found in modified cells called cnidocytes used by cnidarians for defense and prey capture.

S phase

The stage of Interphase where DNA synthesis (replication) occurs and sister chromatids are formed.

Mitosis

The division of the nucleus into two genetically identical nuclei containing the same full set of DNA, occurring in somatic cells.

Synapsis

The pairing of homologous chromosomes that occurs during Prophase I of Meiosis I.

Meiosis

The process of reducing the chromosome number from diploid ($2n$) to haploid ($n$) for the production of gametes.

Selective permeability

A property of the cell membrane that allows only certain molecules to enter while blocking others to maintain homeostasis.

Phospholipid Bilayer

The primary structure of the cell membrane consisting of hydrophilic heads facing outward and hydrophobic tails facing inward.

Cholesterol

Membrane lipids that maintain fluidity, provide stability, and help regulate selective permeability.

Transmembrane Proteins

Integral proteins that extend across the entire phospholipid bilayer and include transport proteins like channels and carriers.

Cystic Fibrosis

A disease caused by a mutated CFTR channel protein, leading to thick, sticky mucus in the lungs.

Passive Transport

The movement of molecules across a membrane without the use of energy ($ATP$), following a concentration gradient.

Crenation

The process where a red blood cell shrinks due to water exiting excessively in a hypertonic solution.

Hemolysis

The process where a red blood cell swells and may burst due to water entering excessively in a hypotonic solution.

Active Transport

Movement of molecules against the concentration gradient (low to high) using energy ($ATP$) and carrier proteins.

Endocytosis

A type of bulk transport that moves materials into the cell, including phagocytosis and pinocytosis.

Type 1 Diabetes

A condition where the pancreas produces little to no insulin, preventing GLUT4 from being signaled to move to the plasma membrane.

Type 2 Diabetes

A condition where cells become resistant to insulin, often due to receptor problems, causing glucose to accumulate in the blood.