Cells - Basic Units of the Body

Flashcards for cell biology review, focusing on vocabulary terms and definitions.

Cell

Basic unit of structure and function in the body.

Differentiated Cells

Cells that have developed specialized characteristics.

Nucleus

Contains genetic material and directs cell activities.

Cytoplasm

Consists of organelles suspended in cytosol.

Cell Membrane

Outer boundary of a cell; maintains integrity and regulates substance passage.

Selectively Permeable

Selectively regulates the entry and exit of substances in a cell.

Signal Transduction

Permits cell to receive and respond to messages.

Hydrophilic Heads

Water-soluble heads that form the surfaces of the cell membrane.

Hydrophobic Tails

Water-insoluble tails that form the interior of the cell membrane.

Cholesterol

Stabilizes membrane and helps keep it impermeable to water-soluble substances.

Cytosol

Fluid portion of the cytoplasm.

Organelles

Tiny solid structures with specific functions in the cell.

Cytoskeleton

Supporting framework of protein rods and tubules within the cytoplasm.

Ribosomes

Composed of protein and RNA; provides structural support and enzyme activity for protein synthesis.

Endoplasmic Reticulum (ER)

Membrane-bound sacs, canals and vesicles that function as a tubular transport system.

Rough Endoplasmic Reticulum (RER)

ER that contains ribosomes and conducts protein synthesis.

Smooth Endoplasmic Reticulum

ER that lacks ribosomes and conducts lipid synthesis.

Vesicles

Membranous sacs that store or transport substances.

Golgi Apparatus

Refines, packages, and delivers proteins made on the RER.

Mitochondria

Membrane-bound, fluid-filled sacs that house chemical reactions extracting energy from nutrients.

Lysosomes

Small membranous sacs that contain enzymes to digest proteins, carbohydrates, nucleic acids, etc.

Peroxisomes

Membranous sacs similar to lysosomes, containing enzymes that digest lipids, alcohol, and hydrogen peroxide.

Microfilaments

Tiny rods of actin that provide cellular movement like muscle contraction.

Microtubules

Larger tubes of tubulin that maintain cell shape, and comprise cilia, flagella, and centrioles.

Intermediate Filaments

Composed of several proteins and support the nuclear envelope of the cell.

Centrosome

Central body consisting of two centrioles near the nucleus.

Centrioles

Cylindrical structures composed of microtubules; produce spindle fibers during cell division.

Cilia

Motile extensions of cell membrane consisting of microtubules, which beat back and forth in a coordinated manner.

Flagella

Motile extension from cell membrane, similar to cilia but much longer, causing the entire cell to move.

Nuclear Envelope

Double-layered membrane surrounding the nucleus.

Nucleolus

Dense body of RNA and protein in the nucleus; site of ribosome production.

Chromatin

Consists of the cell’s chromosomes, containing DNA wound around proteins; stores information for protein synthesis.