1/42
Vocabulary flashcards covering major organelles, cellular structures, and key concepts from the lecture on cell structure and functions.
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
Plasma Membrane
Selective, phospholipid-bilayer boundary that encloses cell contents and regulates substance movement in and out of the cell.
Phospholipid Bilayer
Double layer of amphipathic phospholipids with hydrophilic heads outward and hydrophobic tails inward; basic framework of cell membranes.
Nucleus
Membrane-bound control center of eukaryotic cells that houses DNA and directs activities like protein synthesis and cell division.
Nuclear Envelope
Double membrane surrounding the nucleus, containing pores that control exchange between nucleus and cytoplasm.
Nucleolus
Dense nuclear region where rRNA is transcribed and ribosome subunits are assembled.
Chromatin
Complex of DNA and histone proteins within the nucleus that condenses into chromosomes during cell division.
DNA (Deoxyribonucleic Acid)
Hereditary molecule composed of A, T, C, and G bases; stores the genetic blueprint of an organism.
Mitochondria
Double-membraned, semi-autonomous organelles that perform aerobic respiration and produce ATP; the cell’s “powerhouse.”
Cristae
Folded inner membranes of mitochondria that increase surface area for ATP-generating reactions.
Matrix
Fluid interior of mitochondria containing enzymes, ribosomes, and mitochondrial DNA.
ATP (Adenosine Triphosphate)
Primary energy carrier of the cell, storing energy in high-energy phosphate bonds.
Ribosome
RNA-protein particle that translates mRNA into polypeptides; exists free in cytosol or bound to rough ER.
Endoplasmic Reticulum (ER)
Interconnected network of membrane-bound cisternae continuous with the nuclear envelope; subdivided into rough and smooth regions.
Rough ER
Region of ER studded with ribosomes; synthesizes and begins modification of proteins destined for secretion or membranes.
Smooth ER
Region of ER lacking ribosomes; synthesizes lipids and carbohydrates and performs detoxification.
Vacuole
Membrane-bound sac that stores water, enzymes, wastes, or nutrients and helps maintain turgor pressure and pH.
Cytoskeleton
Network of microtubules, microfilaments, and intermediate filaments that supports cell shape and enables internal movement.
Microtubules
Hollow tubes (~25 nm) of tubulin that form tracks for organelle movement and the mitotic spindle.
Microfilaments (Actin Filaments)
Thin actin strands (~8 nm) involved in muscle contraction, cell motility, and cytoplasmic streaming.
Intermediate Filaments
Rope-like fibers (~10 nm) providing tensile strength and anchoring organelles within the cell.
Plastid
Semi-autonomous, membrane-bound organelle in plants/algae involved in photosynthesis, pigment storage, or food storage.
Chloroplast
Green plastid containing chlorophyll; site of photosynthesis in plants and algae.
Chromoplast
Plastid rich in carotenoid pigments that synthesize and store red, orange, or yellow pigments.
Gerontoplast
Plastid formed from chloroplasts during leaf senescence; salvages nutrients as cells age.
Leucoplast
Colorless plastid specialized for storage of starch (amyloplast), lipids (elaioplast), or proteins (proteinoplast).
Centriole
Cylindrical bundle of microtubule triplets that organizes spindle fibers during eukaryotic cell division.
Mitotic Spindle
Microtubule apparatus that attaches to chromosomes and separates them during mitosis and meiosis.
Lysosome
Single-membrane vesicle containing hydrolytic enzymes that digest macromolecules and recycle cellular components.
Golgi Apparatus
Stack of flattened, membrane-bound cisternae that modifies, sorts, and packages proteins and lipids from the ER.
Cell Wall
Rigid layer outside the plasma membrane that protects, supports, and acts as a filter; made of cellulose in plants, peptidoglycan in bacteria, or chitin in fungi.
Cellulose
Structural polysaccharide forming microfibrils in plant cell walls.
Peptidoglycan
Cross-linked polymer of sugars and amino acids that forms the bacterial cell wall.
Cytoplasm
Cellular region between the plasma membrane and nucleus comprising cytosol and suspended organelles where many metabolic reactions occur.
Cytosol
The aqueous portion of the cytoplasm in which ions, proteins, and organelles are suspended.
Cilia
Short, numerous, microtubule-based projections that beat rhythmically to move cells or fluids past cell surfaces.
Flagella
Long, whip-like microtubule structures that propel cells or generate water currents.
Prokaryote
Single-celled organism lacking a true nucleus and membrane-bound organelles; includes Bacteria and Archaea.
Eukaryote
Organism whose cells possess a true nucleus and membrane-bound organelles; includes animals, plants, fungi, and protists.
Binary Fission
Asexual reproduction in prokaryotes where the cell replicates its DNA and divides into two genetically identical cells.
Mitosis
Eukaryotic nuclear division producing two genetically identical diploid daughter cells.
Meiosis
Two-stage nuclear division in germ cells producing four genetically unique haploid gametes.
Semi-autonomous Organelle
Organelle containing its own DNA and ribosomes, allowing limited self-replication (e.g., mitochondria, plastids).
Nucleoid
Irregularly shaped region in a prokaryotic cell where the circular DNA chromosome is located.