General Cell Structure and Function

Vocabulary flashcards covering cellular organization, organelle structure and function, plasma membrane components, and transport mechanisms based on the lecture notes.

Cell Theory

A biological theory stating that all living things are made up of cells, which are the smallest single units of life, and that all cells come from preexisting cells.

Prokaryotic Cell

A primitive, simpler, and typically smaller cell type that lacks membrane-bound compartments or organelles, with its genetic information freely floating in the cell.

Eukaryotic Cell

A larger cell type containing membrane-bound components called organelles, with a distinct internal structure separating genetic information from other regions.

Organelles

Small membrane-bound structures inside a eukaryotic cell that each perform a specific function.

Microvilli

Finger-like projections on the surface of certain cells, such as in the digestive system, that increase surface area for nutrient absorption while keeping relative cell size small.

Nucleus

The primary organelle that stores genetic information in long strands called chromosomes, serving as the blueprint for cell activities.

Ribosomes

Small cellular structures that latch onto RNA to assemble amino acids into polypeptide strands and proteins.

Free Ribosomes

A population of ribosomes that freely float around inside the cytoplasm of the cell.

Bound Ribosomes

Ribosomes that are stuck to the surface of another organelle, specifically the endoplasmic reticulum.

Polypeptide

A strand produced by linking multiple amino acids together with peptide bonds, forming a protein when containing more than $100$ amino acids.

Rough Endoplasmic Reticulum

A region of the endoplasmic reticulum studded with bound ribosomes that functions in synthesizing and packaging proteins, such as glycoproteins.

Smooth Endoplasmic Reticulum

A region of the endoplasmic reticulum without ribosomes that synthesizes lipids, breaks down carbohydrates, detoxifies drugs and poisons, and stores calcium ions.

Glycoprotein

A molecule formed by chemically bonding a carbohydrate (sugar) to a protein.

Vesicles

Small, bubble-like membrane structures used to transport products to different locations inside or outside the cell.

Golgi Apparatus

The major processing, sorting, and shipping organelle of the cell that receives vesicles from the ER and determines product destinations.

Secretory Vesicles

Vesicles that transport products created inside the cell to the plasma membrane to be exported or secreted outside the cell.

Endocytic Vesicles

Vesicles that bring external products or molecules from outside the cell into the interior of the cell.

Lysosomes

Membrane-bound sacs containing hydrolytic enzymes that function in an acidic environment to digest and break down foreign invaders like bacteria or cellular waste.

Peroxisomes

Enzyme-containing vesicles originating from the Golgi apparatus that wrap around and neutralize toxins, such as alcohol, inside the cell.

Endomembrane System

A cellular system involving the ER, Golgi apparatus, and vesicles that synthesizes, modifies, packages, and transports cellular products.

Mitochondria

The organelle responsible for generating the majority of ATP energy from glucose in the presence of oxygen.

Cytoskeleton

The inner framework and scaffolding of the cell composed of microtubules and microfilaments that holds organelles in place and provides structural support.

Plasma Membrane

A selectively permeable outer boundary composed of a phospholipid bilayer, cholesterol, and embedded proteins that regulates what enters and exits the cell.

Phospholipids

Hydrophobic (water-hating) lipid molecules that form the main structural layer of the plasma membrane.

Cholesterol

A chemical structure wedged between phospholipids in the plasma membrane that maintains membrane fluidity and provides mechanical strength across temperature changes.

Passive Transport

The movement of molecules across the plasma membrane without requiring cellular energy ($ATP$).

Active Transport

The movement of substances across the plasma membrane against their concentration gradient (from low to high concentration) requiring cellular energy ($ATP$).

Bulk Transport

The process of moving large quantities of products or large structures across the plasma membrane all at once using vesicles.

Diffusion

The passive movement of molecules spreading out from an area of high concentration to an area of low concentration until equilibrium is reached.

Osmosis

The diffusion of water across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration.

Isotonic Solution

A solution where the solute concentration is equal inside and outside the cell, resulting in no net movement of water.

Hypertonic Solution

A solution with a higher solute concentration outside the cell than inside, causing water to exit the cell and the cell to shrivel.

Hypotonic Solution

A solution with a lower solute concentration outside the cell than inside, causing water to enter the cell, which can cause the cell to explode or burst.

Facilitated Diffusion

A form of passive transport where channel or carrier proteins help move specific molecules or ions across the plasma membrane without energy.

Sodium-Potassium Pump

An active transport mechanism that uses $ATP$ to move $3$ sodium ions out of the cell and $2$ potassium ions into the cell against their concentration gradients.