Unit 2 – Cell Structure and Function

A series of flashcards covering key terms and definitions related to cell structure and function.

Nucleus

Contains genetic material (DNA) and controls cellular activities.

Ribosomes

Sites of protein synthesis, either free in the cytoplasm or bound to the endoplasmic reticulum.

Endoplasmic Reticulum (ER)

Rough ER modifies proteins; Smooth ER synthesizes lipids and detoxifies substances.

Golgi Apparatus

Modifies, sorts, and packages proteins and lipids for transport.

Mitochondria

Produce ATP by cellular respiration; double membrane and own DNA reflect evolutionary history.

Chloroplasts

Capture light energy for photosynthesis; possess thylakoid membranes and own DNA.

Lysosomes and Peroxisomes

Break down macromolecules and detoxify harmful substances.

Cytoskeleton

Network of protein fibers that maintains cell shape, supports movement, and aids intracellular transport.

Plasma Membrane

Selectively permeable barrier controlling entry and exit of substances.

Surface Area-to-Volume Ratio

The ratio critical for cellular efficiency; affects the ability to exchange materials.

Fluid Mosaic Model

Describes the dynamic structure of the cell membrane, highlighting lipid bilayer and membrane proteins.

Selective Permeability

Allows cells to regulate their internal environments based on membrane structure.

Cell Wall

Provides structural support and protection; composed of different molecules depending on cell type.

Osmosis

Movement of water across selectively permeable membranes from low to high solute concentration.

Passive Transport

No energy required; includes diffusion, facilitated diffusion, and osmosis.

Active Transport

Energy-dependent movement of molecules against concentration gradients using transport proteins.

Endosymbiotic Theory

Explains the origin of organelles like mitochondria and chloroplasts as formerly free-living prokaryotes.

Membrane-Bound Structures

Distinct compartments in eukaryotic cells that allow specialization of functions.

Concentration Gradients

Molecules move from regions of higher to lower concentration or against the gradient requiring energy.

Nucleus

Contains genetic material (DNA) and controls cellular activities.

Ribosomes

Sites of protein synthesis, either free in the cytoplasm or bound to the endoplasmic reticulum.

Endoplasmic Reticulum (ER)

Rough ER modifies proteins; Smooth ER synthesizes lipids and detoxifies substances.

Golgi Apparatus

Modifies, sorts, and packages proteins and lipids for transport.

Mitochondria

Produce ATP by cellular respiration; double membrane and own DNA reflect evolutionary history.

Chloroplasts

Capture light energy for photosynthesis; possess thylakoid membranes and own DNA.

Lysosomes and Peroxisomes

Break down macromolecules and detoxify harmful substances.

Cytoskeleton

Network of protein fibers that maintains cell shape, supports movement, and aids intracellular transport.

Plasma Membrane

Selectively permeable barrier controlling entry and exit of substances.

Surface Area-to-Volume Ratio

The ratio critical for cellular efficiency; affects the ability to exchange materials.

Fluid Mosaic Model

Describes the dynamic structure of the cell membrane, highlighting lipid bilayer and membrane proteins.

Selective Permeability

Allows cells to regulate their internal environments based on membrane structure.

Cell Wall

Provides structural support and protection; composed of different molecules depending on cell type.

Osmosis

Movement of water across selectively permeable membranes from low to high solute concentration.

Passive Transport

No energy required; includes diffusion, facilitated diffusion, and osmosis.

Active Transport

Energy-dependent movement of molecules against concentration gradients using transport proteins.

Endosymbiotic Theory

Explains the origin of organelles like mitochondria and chloroplasts as formerly free-living prokaryotes.

Membrane-Bound Structures

Distinct compartments in eukaryotic cells that allow specialization of functions.

Concentration Gradients

Molecules move from regions of higher to lower concentration or against the gradient requiring energy.

Prokaryotic Cells

Simple cells lacking a membrane-bound nucleus and other membrane-bound organelles; include bacteria and archaea.

Eukaryotic Cells

Complex cells characterized by the presence of a membrane-bound nucleus and other organelles; found in plants, animals, fungi, and protists.

Cell Theory

States that all living things are composed of cells, cells are the basic units of life, and new cells arise from existing cells.