Chapter 02 Levels of Organization of the Human Body - Part 2 (The Cell)

Vocabulary flashcards covering cellular components, membrane structure, transport, and protein synthesis from the notes.

Cell membrane (Plasma Membrane)

A phospholipid bilayer that gives structure to the cell and regulates entry and exit of substances.

Cytoplasm

Fluid inside the cell in which organelles are suspended.

Nucleus

The organelle that houses the cell's DNA.

Mitochondrion

Organelle that performs cellular respiration to produce ATP energy.

Ribosome

Organelle that assembles proteins.

Endoplasmic reticulum (ER)

Network of membranes; rough ER synthesizes proteins; smooth ER synthesizes lipids.

Rough Endoplasmic Reticulum

ER with ribosomes; site of protein synthesis.

Smooth Endoplasmic Reticulum

ER without ribosomes; site of lipid synthesis.

Golgi complex

Stack of membrane-bound folds that modify and inspect proteins and lipids from the ER.

Secretory vesicle

Membrane-bound package carrying materials from the Golgi to the cell membrane for export.

Lysosome

Membrane-bound package containing digestive enzymes.

Cytoskeleton

Network of protein fibers providing structure and movement.

Microvilli

Finger-like projections that increase surface area for absorption.

Cilia

Hair-like projections that move substances along the cell surface.

Phospholipid bilayer

Two-layer arrangement of phospholipids forming the cell membrane.

Glycerol head and fatty acid tails

Hydrophilic glycerol head and hydrophobic fatty acid tails of phospholipids.

Hydrophilic vs hydrophobic

Hydrophilic ends attract water; hydrophobic tails repel water.

Cholesterol

Sterol in the membrane that helps regulate fluidity and stability.

Receptor protein

Membrane protein that binds hormones or specific chemicals.

Channel protein

Protein forming a passageway for substances to cross the membrane.

Glycoprotein

Protein with carbohydrate groups; acts as identification markers on the membrane.

Glycolipid

Lipid with carbohydrate; membrane component that acts as an identification marker.

Carbohydrates (identification markers)

Carbohydrate-containing components on the membrane (glycoproteins, glycolipids) that help identify the cell.

Passive transport

Movement of substances across the membrane down their concentration gradient without energy.

Filtration

Movement of smaller molecules through a membrane due to hydrostatic pressure.

Simple diffusion

Net movement of molecules from high to low concentration due to random motion.

Facilitated diffusion

Diffusion of molecules that cannot cross the membrane directly via carrier or channel proteins.

Osmosis

Diffusion of water across a selectively permeable membrane.

Hypotonic

Solution with lower solute concentration than inside the cell; water tends to enter the cell.

Hypertonic

Solution with higher solute concentration than inside the cell; water tends to leave the cell.

Isotonic

Solutions with equal solute concentration; no net water movement.

Active transport

Movement of substances across a membrane against their concentration gradient; requires energy.

Sodium-potassium pump

Active transport system that pumps Na+ out and K+ into the cell.

Endocytosis

Process by which cells engulf external material into vesicles.

Exocytosis

Process by which vesicles fuse with the membrane to release contents outside the cell.

Bulk transport

Endocytosis and exocytosis; moving large quantities across the membrane.

Transcription

Process of copying DNA into mRNA in the nucleus.

Translation

Process of synthesizing proteins at the ribosome using mRNA and tRNA.

mRNA

Messenger RNA; carries instructions from DNA to the ribosome for protein synthesis.

tRNA

Transfer RNA; brings specific amino acids to the ribosome during translation; contains anticodons.