Study of Life and Cellular Biology Flashcards

Vocabulary practice flashcards generated from lecture notes covering the scientific method, biomolecules, cell structures, membrane transport mechanisms, and neuronal action potentials.

Independent Variable

The variable in an experiment that is intentionally manipulated by the researcher, typically plotted on the x-axis.

Dependent Variable

The variable in an experiment that changes in response to the independent variable, typically plotted on the y-axis.

Controlled Variables

The constant factors in an experiment that are kept unchanged to serve as a baseline for comparison.

Spurious Correlation

A mathematical relationship in which two or more variables are associated but not causally linked due to coincidence or an unseen confounding variable.

Dehydration Synthesis

A chemical reaction that connects monomers together to form polymers through the removal and release of a water molecule ($H_2O$).

Hydrolysis

A chemical process that breaks polymers down into individual monomers through the addition of water ($H_2O$), where one part gains $H^+$ and the other gains $OH^-$.

Monosaccharide

A simple sugar monomer containing carbon, hydrogen, and oxygen typically in a $1:2:1$ ratio.

Phospholipid Bilayer

A double-layer membrane structure composed of phospholipids with hydrophilic polar heads facing exterior environments and hydrophobic nonpolar tails on the interior.

Denaturation

The process in which a protein loses its natural shape and functional properties due to environmental changes such as altered temperature or pH.

Primary Protein Structure

The unique linear sequence of amino acids linked together in a single polypeptide chain.

Secondary Protein Structure

Local folding patterns within a polypeptide chain, such as alpha-helices or beta-sheets, stabilized by hydrogen bonds.

Tertiary Protein Structure

The overall three-dimensional shape formed by a single folded polypeptide chain.

Quaternary Protein Structure

The protein structure formed from the assembly of multiple distinct polypeptide subunits.

Anabolic Reaction

A metabolic reaction requiring an input of energy to build complex polymers from simpler monomers.

Catabolic Reaction

A metabolic reaction that releases energy by breaking down complex polymers into simpler monomers.

Cellulose

A structural polysaccharide composed of glucose monomers that forms the rigid cell walls in plant cells.

Chitin

A structural polysaccharide that forms the tough exoskeleton of arthropods.

Cell Organelles

Specialized membrane-bound structures located within the cytosol of eukaryotic cells that perform distinct physiological roles.

Mitochondria

Membrane-bound organelles where cellular respiration occurs to produce cellular energy in the form of $ATP$.

Golgi Apparatus

An organelle that receives proteins and lipids from the endoplasmic reticulum to further modify, package, and tag them for transport.

Endosymbiotic Theory

The theory stating that mitochondria and chloroplasts originated as free-living prokaryotic organisms that were engulfed by an ancestral eukaryotic cell.

Passive Transport

The movement of molecules across a cell membrane along their concentration gradient (from high to low concentration) without expending cellular energy ($ATP$).

Active Transport

The movement of molecules across a cell membrane against their concentration gradient (from low to high concentration), requiring cellular energy ($ATP$).

Plasma Membrane Structure

A selectively permeable phospholipid bilayer embedded with proteins, cholesterol, glycolipids, and glycoproteins.

Facilitated Diffusion

Passive transport of substances across a cell membrane down their concentration gradient assisted by channel or carrier transport proteins.

Osmosis

The passive diffusion of water across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Hypotonic Solution

A solution with a lower solute concentration than the cell interior, causing water to enter the cell and leading to swelling or lysis.

Hypertonic Solution

A solution with a higher solute concentration than the cell interior, causing water to leave the cell and leading to cellular shriveling.

Neuron

The primary signaling cell of the nervous system, responsible for generating and conducting electrical and chemical signals.

Action Potential

A rapid, temporary reversal of electrical membrane potential along a neuronal axon caused by movement of charged ions.

Depolarization

The phase of an action potential where voltage-gated $Na^+$ channels open to let $Na^+$ into the cell, making the membrane potential inside more positive.

Repolarization

The phase of an action potential where $Na^+$ gates close and $K^+$ channels open to release $K^+$ from the cell, restoring negative interior charge.

Astrocytes

Star-shaped glial cells in the central nervous system that supply nutrients to neurons, provide structural support, and block pathogens.

Schwann Cells

Glial cells in the peripheral nervous system that wrap around neuronal axons to form the insulating myelin sheath.

Saltatory Conduction

The rapid propagation of an electrical impulse along a myelinated axon achieved by the signal jumping from node of Ranvier to node of Ranvier.