Biology 1050 Exam 2 Study Guide Flashcards

A complete set of vocabulary flashcards covering basic cell biology and metabolism based on the Biol 1050 Exam 2 Study Guide.

Cell Theory

A fundamental biological concept consisting of three major principles explaining the origin and existence of all cells.

Prokaryotic Cells

A type of cell found in specific groups that lacks a nucleus and membrane-bound organelles.

Eukaryotic Cells

A type of cell that contains a nucleus and membrane-bound organelles, found in certain multicellular and unicellular organisms.

Unicellular Organisms

Organisms consisting of a single cell that performs all functions of life.

Multicellular Organisms

Organisms consisting of many specialized cells working together.

Surface-to-Volume Ratio

The relationship that explains why cells are generally small; as cell size increases, this ratio decreases, affecting the efficiency of material exchange.

Plasma Membrane

A selectively permeable barrier that surrounds the cell and regulates the movement of materials.

Selective Permeability

A property of biological membranes that allows some substances to cross more easily than others.

Cytoplasm

The internal region of a cell between the plasma membrane and the nucleus.

Cytosol

The fluid portion of the cytoplasm in which organelles are suspended.

Nucleus

The organelle that houses the genetic material of the cell and manages its functions.

Nuclear Envelope

The double membrane surrounding the nucleus.

Nuclear Pores

Openings in the nuclear envelope that regulate the entry and exit of molecules.

Nucleolus

A structure within the nucleus responsible for the production of ribosomes.

Chromatin

A complex composed of DNA and proteins that condenses to form chromosomes.

Chromosomes

The organized, condensed form of chromatin found within the nucleus during cell division.

Ribosomes

Cellular structures responsible for protein synthesis, often associated with the rough ER.

Endomembrane System

A collection of membranes and organelles including the ER, Golgi apparatus, and vesicles that regulate protein traffic and metabolic functions.

Rough ER

A region of the endoplasmic reticulum studded with ribosomes involved in protein production.

Smooth ER

A region of the endoplasmic reticulum that lacks ribosomes.

Golgi Apparatus

An organelle that functions in modifying, sorting, and packaging materials from the ER.

Vesicles

Membranous sacs that contribute to intracellular transport.

Vacuoles

Large membrane-bound sacs used for storage and various cellular functions.

Mitochondria

The organelle that releases energy from organic compounds using oxygen.

Chloroplasts

The organelle found in plant cells that uses sunlight to produce carbohydrates.

Cytoskeleton

A network of fibers throughout the cytoplasm that provides structural support and aids in cell movement.

Microfilaments

Cytoskeletal components involved in changing cell shape and amoeboid movement.

Microtubules

Components of the cytoskeleton that provide structure and serve as tracks for movement.

Pseudopods

Extrusions of the cell used by organisms like amoebas for movement and feeding.

Cilia

Short, hair-like appendages that facilitate cellular movement.

Flagella

Long, tail-like appendages used for cellular locomotion.

Fluid Mosaic Model

A model describing the membrane as a mosaic of proteins floating in a fluid bilayer of phospholipids.

Phospholipid

An amphipathic molecule with a hydrophilic head and two hydrophobic tails that forms the structural basis of cell membranes.

Amphipathic

A characteristic of a molecule, like a phospholipid, having both a hydrophilic region and a hydrophobic region.

Membrane Proteins

Proteins embedded in the membrane that determine functions such as transport, enzymatic activity, signal transduction, and cell-cell recognition.

Diffusion

The passive movement of molecules from an area of high concentration to an area of low concentration.

Concentration Gradient

A region along which the density of a chemical substance increases or decreases.

Dynamic Equilibrium

A state in which the concentration of a substance is equal on both sides of a membrane, and molecules cross at equal rates.

Passive Transport

The diffusion of a substance across a biological membrane without the expenditure of energy.

Osmosis

The diffusion of water across a selectively permeable membrane.

Aquaporins

Specific channel proteins that facilitate the rapid movement of water across the plasma membrane.

Hypertonic

A solution with a higher concentration of non-penetrating solutes compared to the cell, causing the cell to lose water.

Hypotonic

A solution with a lower concentration of non-penetrating solutes compared to the cell, causing the cell to gain water.

Isotonic

A solution with the same concentration of non-penetrating solutes as the cell, resulting in no net water movement.

Facilitated Diffusion

The passage of molecules across a membrane down their concentration gradient with the assistance of specific transport proteins.

Active Transport

The movement of a substance across a cell membrane against its concentration gradient, mediated by specific transport proteins and requiring an expenditure of energy.

Endocytosis

A type of bulk transport where the cell takes in substances by forming new vesicles from the plasma membrane.

Exocytosis

A type of bulk transport where the cell secretes biological molecules by the fusion of vesicles with the plasma membrane.

Metabolism

The totality of an organism's chemical reactions.

Metabolic Pathway

A series of chemical reactions that either builds a complex molecule or breaks down a complex molecule into simpler compounds.

Catabolic Pathways

Metabolic pathways that release energy by breaking down complex molecules into simpler compounds.

Anabolic Pathways

Metabolic pathways that consume energy to build complicated molecules from simpler ones.

Energy

The capacity to cause change or do work.

Kinetic Energy

The energy associated with the relative motion of objects.

Potential Energy

The energy that matter possesses because of its location or structure.

Chemical Energy

A term used by biologists to refer to the potential energy available for release in a chemical reaction.

First Law of Thermodynamics

The principle stating that energy cannot be created or destroyed, only transferred or transformed.

Second Law of Thermodynamics

The principle stating that every energy transfer or transformation increases the entropy of the universe.

Entropy

A measure of molecular disorder or randomness.

Exergonic Reaction

A spontaneous chemical reaction in which there is a net release of free energy.

Endergonic Reaction

A non-spontaneous chemical reaction in which free energy is absorbed from the surroundings.

ATP (Adenosine Triphosphate)

The cell's main energy shuttle, used to drive endergonic reactions by transferring a phosphate group.

ATP Hydrolysis

The process of breaking the bonds between the phosphate groups of ATP, which releases energy.

Energy Coupling

The use of an exergonic process to drive an endergonic one, mediated by ATP.

Enzyme

A macromolecule that serves as a catalyst, changing the rate of a chemical reaction without being consumed by the reaction.

Substrate

The specific reactant on which an enzyme acts.

Active Site

The specific region of an enzyme that binds the substrate and that forms the pocket in which catalysis occurs.

Activation Energy

The amount of energy that reactants must absorb before a chemical reaction will start.