BIO1 MIDTERM: TOPIC 2 Scientists and Cells (PROKARYOTIC/EUKARYOTIC)

Robert Hooke

Devised an early microscope, named porous cork structures "cellulae," and was the first credited with publishing a description of seeing a cell in 1666.

Antonie van Leeuwenhoek

First to observe and study living cells ("animalcules") in pond water, blood, and tartar using a simple one-lens microscope.

Matthias Jacob Schleiden

German botanist who concluded that all plants are composed of cells.

Theodor Schwann

German physiologist who concluded that all animals are composed of cells and helped establish cell theory.

Rudolf Virchow

German physician who proposed that all cells arise from pre-existing cells through cell division.

First Tenet of Cell Theory

All organisms are composed of one or more cells.

Second Tenet of Cell Theory

Cells are the smallest and basic units of structure and function in organisms.

Third Tenet of Cell Theory

Cells arise only from previously existing cells.

Prokaryotic Cell

Simple, smaller cell that lacks a distinct nucleus and membrane-bound organelles, evolved around 3.5 billion years ago.

Eukaryotic Cell

Complex, larger cell containing a distinct membrane-bound nucleus and organized organelles, evolved around 1.8 billion years ago.

Plasma Membrane

Semipermeable outer barrier that controls the movement of molecules, ions, and gases into and out of the cell.

Cell Wall

Rigid outer boundary maintaining shape and structural support, composed of cellulose in plants, chitin in fungi, and peptidoglycan in bacteria.

Capsule

Protective outer polysaccharide layer found lying outside the cell wall in prokaryotes.

Nucleoid Region

Irregularly shaped area in prokaryotes where genetic material in the form of DNA is stored without a nuclear membrane.

Cytoplasm

Internal fluid-filled space between the nucleus and cell membrane containing cytosol and suspended cellular structures.

Ribosomes

Small organelles where amino acids are assembled to synthesize proteins.

Plasmid

Independent circular DNA structure in prokaryotes providing genetic advantages such as antibiotic resistance.

Flagellum

Long, tail-like appendage that rotates or moves in a whiplike motion to propel cells forward.

Fimbriae

Small, bristle-like fibers on prokaryotic surfaces that allow bacteria to attach to objects and tissues.

Conjugation Pili

Tubular structures on bacterial surfaces used for cell-to-cell communication and transferring DNA between cells.

Nucleus

Storehouse of genetic information in the form of DNA in eukaryotic cells that protects DNA from damage.

Nuclear Envelope

Double membrane surrounding the nucleus perforated with nuclear pores to allow passage of large molecules.

Nucleolus

Dense region inside the nucleus where ribosomes are assembled.

Chromatin

Complex structure formed by DNA packaged with specialized proteins called histones.

Endoplasmic Reticulum

Interconnected network of folded membranes forming an internal maze (lumen) for protein and lipid synthesis.

Rough Endoplasmic Reticulum

Membrane network studded with ribosomes that modifies and folds proteins for secretion or membrane insertion.

Smooth Endoplasmic Reticulum

Membrane network lacking ribosomes that synthesizes lipids and detoxifies drugs and alcohol.

Golgi Apparatus

Layered stacks of membrane-bound sacs that modify, sort, package, and ship proteins to various cell destinations.

Vesicles

Small, short-lived membrane-bound sacs that enclose and transport materials between cell organelles.

Vacuoles

Fluid-filled storage sacs for water, food molecules, inorganic ions, and enzymes; large and central in plant cells, small in animal cells.

Lysosomes

Round membrane-bound organelles containing lysozyme enzymes to digest waste, worn-out organelles, and foreign invaders.

Peroxisomes

Single-membrane organelles containing oxidative enzymes and catalase to break down complex molecules and turn toxic hydrogen peroxide into water and oxygen.

Mitochondria

Double-membraned organelles that supply energy (ATP) to the cell and contain their own DNA and ribosomes.

Chloroplasts

Plant organelles containing thylakoids and green chlorophyll that convert solar energy into chemical energy via photosynthesis.

Thylakoids

Sacs organized in stacks called grana inside chloroplasts where light absorption occurs.

Stroma

Fluid portion of the chloroplast surrounding the thylakoids.

Centrosome

Small, dense region of cytoplasm that serves as the main microtubule-organizing center.

Centrioles

Pair of perpendicular barrel-like structures in animal cells aiding in cell division and microtubule organization.

Cilia

Short, hair-like projections that move in a coordinated fashion for cell locomotion or sweeping fluids across tissue surfaces.

Cytoskeleton

Flexible network framework of protein fibers providing sturdy mechanical support, organelle anchorage, and movement direction.

Microtubules

Thickest, stiff hollow protein tubes of the cytoskeleton that give shape, form spindle fibers in division, and act as transport tracks.

Intermediate Filaments

Rope-like cytoskeletal fibers providing tensile strength to resist mechanical stress in skin, hair, and claws.

Microfilaments

Thinnest cytoskeletal fibers (also called actin filaments) forming a protective mesh under the plasma membrane and enabling muscle contraction and movement.

Plasmodesmata

Tiny channels passing through plant cell walls that connect neighboring cytoplasms for direct communication and transport.

rare lysosomes, centrosome is absent in most

Parts of a plant cell lack

cell wall, chloroplast, and plasmodesmata

parts of an animal cell lack

Cell wall

what part is no. 1?

Cell membrane

what part is no. 2?

Cytoplasm

what part is no. 3?

Chloroplast

what part is no. 4?

Central vacuole

what part is no. 5?

Mitochondrion

what part is no. 6?

Plasmodesmata

what part is no. 7 located in the cell wall?

Nucleus

what part is no. 8?

Nucleolus

what part is no. 9?

Rough ER

what part is no. 10?

Smooth ER

what part is no. 11?

Golgi apparatus

what part is no. 12?

Ribosomes

what part is no. 13?

Cell membrane

what part is no. 1?

Cytoplasm

what part is no. 2?

Mitochondrion

what part is no. 3?

Lysosome

what part is no. 4?

Ribosomes

what part is no. 5?

Centrioles

what part is no. 6?

Nucleus

what part is no. 7?

Nucleolus

what part is no. 8?

Rough ER

what part is no. 9?

Smooth ER

what part is no. 10?

Golgi apparatus

what part is no. 11?

Vesicle

what part is no. 12?