Cell Structure, Function, and Exploring Life

Vocabulary flashcards covering cell structure, organelles, transport, cellular respiration, biological organization, scientific process, and global health concepts based on the lecture material.

Cell Theory

The biological principle stating that the cell is the basic unit of life, all living things are made of cells, and new cells arise only from preexisting cells.

Compound Light Microscope

A microscope with lower magnification that uses glass lenses and light beams to view live specimens directly with the human eye.

Transmission Electron Microscope

A microscope that projects a 2-D image onto a screen using a stream of electrons, providing high magnification without live specimens.

Scanning Electron Microscope

A microscope that uses a beam of electrons to view surface structures of specimens in 3-D at high magnification without live specimens.

Prokaryotic Cells

Cells that lack a nucleus and include two groups of bacteria: eubacteria and archaebacteria.

Eukaryotic Cells

Cells containing a nucleus, encompassing animals, plants, fungi, and protists.

Endosymbiosis

The evolutionary process wherein eukaryotic organelles may have developed from ancient eukaryotes engulfing prokaryotic cells.

Fluid-Mosaic Model

A model describing the plasma membrane as a phospholipid bilayer with the consistency of oil at body temperature, where embedded proteins freely move laterally.

Aquaporins

Specific membrane channel proteins that allow water molecules to cross the plasma membrane.

Osmosis

The diffusion of water molecules across a selectively permeable membrane from a higher water concentration to a lower water concentration.

Isotonic Solution

A solution having the same concentration of impermeable solutes as body cells, resulting in no cell size change.

Hypotonic Solution

A solution containing fewer solutes than body cells, causing water to enter the cell so it swells and can burst (lysis).

Hypertonic Solution

A solution containing more solutes than body cells, causing water to leave the cell so it shrinks (crenation).

Sodium–Potassium Pump

An active transport protein pump active in all body cells that uses ATP to move sodium ions ($Na^+$) out of the cell and potassium ions ($K^+$) in.

Phagocytosis

A form of endocytosis where white blood cells engulf pathogens, such as bacteria.

Pinocytosis

A form of endocytosis where a cell ingests fluid containing small particles.

Receptor-Mediated Endocytosis

A form of endocytosis initiated when target particles bind to specific receptor proteins in the plasma membrane.

Nucleolus

A dark region inside the cell nucleus responsible for producing ribosomes.

Rough Endoplasmic Reticulum

A membranous organelle studded with ribosomes that functions in protein synthesis.

Smooth Endoplasmic Reticulum

A membranous organelle lacking ribosomes that functions in synthesizing lipids.

Golgi Apparatus

An organelle composed of flattened sacs involved in modifying, processing, packaging, and secreting proteins and lipids.

Lysosomes

Vesicles made by the Golgi apparatus that contain hydrolytic enzymes to break down molecules into smaller parts.

Polyribosomes

Groups of free-floating ribosomes in the cytoplasm that synthesize proteins.

Adhesion Junctions

Intercellular junctions that attach the cytoskeletons of adjacent cells together.

Tight Junctions

Intercellular junctions that produce a barrier between adjacent cells.

Gap Junctions

Intercellular junctions formed by fused channels that allow direct communication between cells.

Feedback Inhibition

A metabolic regulation mechanism where an end product interacts with an enzyme early in the pathway to slow product production.

Active Site

The specific area on an enzyme where a substrate binds.

Glycolysis

An anaerobic metabolic pathway in the cytoplasm that breaks a 6-carbon glucose into two 3-carbon pyruvates, producing NADH and $2\,ATP$.

Citric Acid Cycle

A cyclical enzymatic pathway in the mitochondrial matrix that breaks down acetyl CoA, releases $CO_2$, and produces NADH, $FADH_2$, and $2\,ATP$.

Electron Transport Chain

An aerobic series of carrier proteins in mitochondrial cristae that pass electrons to oxygen to form $H_2O$, releasing energy to produce $32\text{--}34\,ATP$.

Fermentation

An anaerobic pathway occurring in the absence of oxygen that produces $2\,ATP$ per glucose and toxic lactate.

Homeostasis

The state of maintaining a constant internal environment within an organism.

Metabolism

The sum of all chemical reactions that occur within a cell or organism.

Photosynthesis

A process used by plants, algae, and some bacteria to harvest solar energy and convert it into chemical energy stored in sugars.

Inductive Reasoning

A logical process where creative thinking is used to combine individual facts into a cohesive whole.

Deductive Reasoning

A logical process using 'if, then' logic to test a hypothesis.

Scientific Theory

An accepted explanation for how the world works that is supported by scientific evidence.

Emerging Diseases

Relatively new infectious diseases, such as avian influenza, swine flu, SARS, MERS, and COVID-19.

Reemerging Diseases

Infectious diseases that have been known for some time and considered low risk but experience occasional outbreaks, such as Ebola.