Module 1B: Fundamentals of Life - Cell Biology, Cellular Transport, and Cellular Energy

Vocabulary practice flashcards covering cell biology, plasma membrane structures, cellular transport mechanisms, and cellular energy processes.

Anabolic Reaction

A metabolic process where small molecules are built into larger ones, requiring an input of energy.

Catabolic Reaction

A metabolic process where large molecules are broken down into smaller ones, releasing energy.

First Law of Thermodynamics

The physical law stating that energy can be neither created nor destroyed, only transferred or transformed from one place to another.

Potential Energy

Energy that is stored and has the potential to cause work or change.

Kinetic Energy

The energy associated with motion.

Photosynthesis

The process performed by plants that converts solar light energy, carbon dioxide, and water into sugars and oxygen, represented by the equation $6\text{CO}_2 + 6\text{H}_2\text{O} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2$.

Cellular Respiration

The metabolic reaction in cells that breaks down glucose in the presence of oxygen to produce ATP, releasing carbon dioxide and water as waste, represented by $6\text{O}_2 + \text{C}_6\text{H}_{12}\text{O}_6 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O}$.

Adenosine Triphosphate (ATP)

An energy-supplying molecule that powers cellular processes and functions like a rechargeable battery within the cell.

Fluid Mosaic Model

A model describing the structure of the plasma membrane as a mosaic of phospholipids, cholesterol, proteins, and carbohydrates.

Phospholipid Bilayer

A two-layered arrangement of phospholipid molecules with hydrophilic heads facing outward and hydrophobic tails facing inward, forming the fundamental structure of the plasma membrane.

Cholesterol (Membrane)

A lipid component of the plasma membrane that regulates membrane fluidity and acts as an antifreeze.

Membrane Proteins

Proteins embedded in or associated with the plasma membrane that serve as channels or pumps to move materials into or out of the cell.

Membrane Carbohydrates

Sugar chains consisting of $2$ to $60$ units attached to proteins or lipids on the cell surface that allow cells to recognize each other.

Passive Transport

The movement of substances across a cell membrane along their concentration gradient without requiring cellular energy.

Diffusion

The spontaneous movement of molecules down a concentration gradient from an area of higher concentration to lower concentration.

Osmosis

A specific type of passive transport involving the movement of water (not solute) across a membrane depending on the solution surrounding the cell.

Osmolarity

The total amount of solutes dissolved in a given solution.

Isotonic Solution

A solution in which the osmolarity of the extracellular fluid is the same as the osmolarity inside the cell.

Hypertonic Solution

A solution in which the osmolarity of the extracellular fluid is higher than inside the cell, causing water to leave the cell.

Hypotonic Solution

A solution in which the osmolarity of the extracellular fluid is lower than inside the cell, causing water to enter the cell.

Facilitated Transport

The spontaneous movement of molecules down a concentration gradient with the help of transporter proteins, without using energy.

Active Transport

The movement of a solute against its concentration gradient (from lower to higher concentration), requiring specific transporter proteins and energy in the form of ATP.

Light Microscope

An optical instrument used to view single cells that magnifies around $400\times$ (up to $1000\times$) and resolves objects down to approximately $0.2\,\mu\text{m}$.

Cytoplasm

The region inside the cell containing cytosol and suspended cellular structures (excluding the nucleus in eukaryotic cells).

Cytosol

The jelly-like fluid inside the cell composed mostly of water containing dissolved proteins, nucleic acids, ions, and other materials.

Prokaryotic Cells

Unicellular organisms meaning 'before the nucleus' that are smaller and structurally less compartmentalized than eukaryotic cells, including Bacteria and Archaea.

Eukaryotic Cells

Cells meaning 'true nucleus' that are large and complex with internal membranes and membrane-bound organelles, found in protists, plants, fungi, and animals.

Cell Wall (Plant)

A rigid outer structure in plant cells containing cellulose that maintains cell shape, provides physical support, offers protection, and prevents excessive water uptake.

Organelles

Small, specialized structures within a eukaryotic cell, many surrounded by a lipid bilayer, that perform specific cellular functions.

Endomembrane System

A group of membrane-bound organelles—including the nuclear envelope, endoplasmic reticulum, Golgi apparatus, vesicles, lysosomes, vacuoles, and plasma membrane—that work together to make, modify, package, and transport proteins and lipids.

Nucleus

The organelle in eukaryotic cells that stores and protects DNA, regulates access to genetic information, and serves as the site for transcription.

Rough Endoplasmic Reticulum

A membrane network studded with ribosomes that serves as an attachment site for translating mRNA into proteins destined for secretion, membranes, or the endomembrane system.

Golgi Apparatus

An organelle that sorts, tags, packages, and distributes proteins and lipids into vesicles to ensure they reach their correct destinations.

Vesicles

Small membrane-bound sacs that transport proteins, lipids, and other materials to designated locations inside or outside the cell.

Mitochondria

Known as the 'powerhouse of the cell,' these organelles convert energy from food molecules into ATP via cellular respiration.

Lysosomes

Organelles functioning as the cell's 'garbage disposal' that contain digestive enzymes to break down macromolecules, damaged cell components, and foreign material.

Central Vacuole

A large plant organelle filled with cell sap that stores nutrients, breaks down cellular components, maintains turgor pressure against the cell wall, and stores pigments or defensive compounds.

Chloroplasts

Plant organelles that perform photosynthesis by capturing light energy to synthesize sugars from carbon dioxide and water.

Chlorophyll

A green pigment contained within chloroplasts that absorbs light energy necessary for photosynthesis.