Cells reworked

Cell Theory

A foundational principle in biology stating that all organisms are composed of cells, all cells come from preexisting cells, and cells are the smallest structural and functional unit of organisms.

Prokaryotic Cells

Cells that lack a membrane-bound nucleus and are structurally smaller and simpler than eukaryotic cells.

Eukaryotic Cells

Cells that contain a membrane-bound nucleus that houses DNA and specialized organelles.

Plasma Membrane

A flexible boundary between the cell and its surroundings, primarily made up of a phospholipid bilayer.

Cytoplasm

The region inside the outer plasma membrane of the cell excluding the nucleus.

Ribosomes

The site of protein synthesis in the cell, composed of rRNA and consisting of large and small subunits.

Endoplasmic Reticulum (ER)

A system of membrane channels that synthesizes proteins (rough ER) and lipids (smooth ER).

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Lysosomes

Membrane-bound vesicles that contain digestive enzymes and are involved in digestion and recycling of cellular resources.

Vesicles

Small structures that contain liquid or cytoplasm and are surrounded by a lipid bilayer, transporting materials between organelles.

Chloroplasts

Organelles in plant cells that are the site of photosynthesis and are characterized by a double membrane and thylakoids.

Mitochondria

Organelles that produce ATP through the breakdown of carbohydrates and are surrounded by a double membrane.

Cytoskeleton

A network of fibers that maintains cell structure and assists in the movement of cells and organelles.

Centrioles

Short, hollow cylinders that help separate chromosomes during cell division and may give rise to cilia and flagella.

Cell Wall

A rigid exterior structure that supports and protects plant cells, made primarily of cellulose.

Fluid Mosaic Model

Model describing the structure of the plasma membrane as a fluid lipid bilayer with embedded proteins.

Passive Transport

Movement of molecules across the membrane without energy input, typically down their concentration gradient.

Active Transport

The movement of molecules against their concentration gradient, requiring energy in the form of ATP.

Diffusion

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

Exocytosis

The process by which vesicles fuse with the plasma membrane to secrete their contents outside the cell.

Endocytosis

The process by which cells engulf substances from their environment, forming vesicles.

Osmosis

The diffusion of water across a selectively permeable membrane.

Hypertonic Solutions

Solutions with a higher concentration of solute compared to the interior of a cell, causing cells to shrink.

Hypotonic Solutions

Solutions with a lower concentration of solute compared to the interior of a cell, causing cells to swell.

Isotonic Solutions

Solutions with equal concentrations of solute and water on both sides of the membrane, resulting in no net movement of water.

Filtration

The process of removing unwanted substances from the blood, occurring in the kidneys.

Reabsorption

The process that transfers water and solutes from the filtrate back into the blood in the kidneys.

Excretion

The removal of waste materials from the body, primarily through urine production in the kidneys.

Kidney Stones

Solid, pebble-like pieces of material that can form in the kidney when certain minerals are present.

Dialysis

A medical procedure that filters waste products from the blood when the kidneys are unable to do so.

UTIs (Urinary Tract Infections)

Infections typically in the bladder that can spread to the kidneys, often caused by E. coli.

Homeostasis

The process of maintaining a stable internal environment in the body, including regulation of water and solute levels.

Nucleus

The command center of the cell that houses DNA and is separated by a nuclear envelope.

Chromatin

A complex of DNA and proteins found in the nucleus, which condenses to form chromosomes during cell division.

Vacuoles

Larger membranous sacs that store materials in excess within cells.

Cilia

Short hairlike projections found on the surface of some cells that assist in cell movement.

Flagella

Long, threadlike projections that enable some cells to move.

Protein Synthesis

The process by which ribosomes create proteins, based on genetic instructions from DNA.

Golgi Apparatus Function

Modifies proteins and lipids received from the endoplasmic reticulum and prepares them for transport.

Channel Proteins

Proteins that allow specific molecules to pass through the plasma membrane.

Carrier Proteins

Proteins that bind to molecules and aid in their transport across the plasma membrane.

Receptor Proteins

Proteins that bind to specific molecules, allowing a cell to respond to signals.

Enzymatic Proteins

Proteins that catalyze metabolic reactions within the cell.

Glycoproteins

Proteins with carbohydrate groups attached that play a role in cell recognition.

Peptidoglycan

A polymer that strengthens the cell wall in bacteria.

Thylakoids

Disc-like structures within chloroplasts, stacked to form grana, involved in photosynthesis.

Cristae

Folds of the inner membrane in mitochondria, increasing surface area for ATP production.

Stroma

The semi-fluid substance surrounding thylakoids in chloroplasts where the light-independent reactions occur.

Nucleolus

A dark region within the nucleus responsible for producing ribosomal RNA (rRNA).

Renal Vein

The blood vessel that carries filtered blood away from the kidneys.

Renal Artery

The blood vessel that supplies blood to the kidneys.

Urethra

The duct through which urine is discharged from the bladder to the exterior of the body.

Ureter

The tube that carries urine from the kidneys to the bladder.

Bladder

The organ that stores urine before it is excreted from the body.

Filtrate

A liquid that has passed through a filter, in this case, containing water, urea, and valuable solutes from blood.

Urochrome

The yellow pigment produced from the breakdown of hemoglobin that gives urine its color.

Turgor Pressure

The pressure exerted by fluid in a plant cell that helps maintain its shape.

Chromosomes

Structures formed from condensed chromatin during cell division, containing genetic information.