Cell Structure and Function Quiz

Prokaryotic Cells:
- Lack a nucleus and membrane-bound organelles.
- Generally smaller (0.1 - 5.0 µm).
- Example: Bacteria and Archaea.
Eukaryotic Cells:
- Have a nucleus and membrane-bound organelles.
- Larger (10 - 100 µm).
- Example: Plant and animal cells.

Cell Membrane:
- Semi-permeable barrier.
- Composed of a phospholipid bilayer with proteins.
Cytoplasm:
- Jelly-like substance inside the cell.
- Contains organelles, cytoskeleton, and various molecules.
Nucleus:
- Contains genetic material (DNA).
- Surrounded by a nuclear envelope with pores.
Ribosomes:
- Sites of protein synthesis.
- Found free in the cytoplasm or attached to the endoplasmic reticulum (ER).
Mitochondria:
- Powerhouse of the cell.
- Site of ATP (energy) production through cellular respiration.
Endoplasmic Reticulum (ER):
- Rough ER: Studded with ribosomes; involved in protein synthesis and modification.
- Smooth ER: Lacks ribosomes; involved in lipid synthesis and detoxification.
Golgi Apparatus:
- Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.
Lysosomes:
- Contain digestive enzymes.
- Responsible for breaking down waste materials and cellular debris.
Peroxisomes:
- Contain enzymes for fatty acid oxidation and detoxification of hydrogen peroxide.
Cytoskeleton:
- Network of fibers providing structural support and shape.
- Composed of microfilaments, intermediate filaments, and microtubules.

Cell Wall:
- Rigid outer layer providing support and protection.
- Composed of cellulose.
Chloroplasts:
- Sites of photosynthesis.
- Contain chlorophyll and have a double membrane.
Central Vacuole:
- Large organelle for storage and maintaining cell turgor pressure.

Metabolism:
- Sum of all chemical reactions within a cell.
- Includes catabolism (breaking down molecules) and anabolism (building up molecules).
Homeostasis:
- Maintenance of stable internal conditions despite external changes.
Cell Communication:
- Cells communicate through direct contact or chemical signals (hormones, neurotransmitters).
Reproduction:
- Mitosis: Cell division resulting in two identical daughter cells.
- Meiosis: Cell division producing gametes with half the chromosome number.

Passive Transport:
- Movement of substances across cell membrane without energy (e.g., diffusion, osmosis).
Active Transport:
- Movement of substances against concentration gradient, requiring energy (e.g., sodium-potassium pump).
Endocytosis/Exocytosis:
- Endocytosis: Process of taking in materials by engulfing them.
- Exocytosis: Process of expelling materials from the cell.

Prokaryotic Cells:
- No nucleus or membrane-bound organelles, typically smaller in size (0.1 - 5.0 µm).
- Examples include bacteria and archaea.
Eukaryotic Cells:
- Contain a nucleus and membrane-bound organelles, generally larger (10 - 100 µm).
- Examples include plant and animal cells.

Cell Membrane:
- Functions as a semi-permeable barrier made of a phospholipid bilayer interspersed with proteins.
Cytoplasm:
- A jelly-like medium that houses organelles, cytoskeleton, and various molecules.
Nucleus:
- Houses genetic material (DNA) and is encased in a nuclear envelope containing pores for substance exchange.
Ribosomes:
- Protein synthesis sites located freely in the cytoplasm or attached to the endoplasmic reticulum (ER).
Mitochondria:
- Known as the cell's powerhouse, responsible for ATP production through cellular respiration.
Endoplasmic Reticulum (ER):
- Rough ER: Ribosome-studded, involved in protein synthesis and modification.
- Smooth ER: Lacks ribosomes, involved in lipid synthesis and detoxification functions.
Golgi Apparatus:
- Modifies, sorts, and packages proteins and lipids for secretion or targeted delivery within the cell.
Lysosomes:
- Organelles containing digestive enzymes that break down waste materials and cellular debris.
Peroxisomes:
- Contain enzymes for fatty acid oxidation and detoxification of hydrogen peroxide.
Cytoskeleton:
- A structural framework composed of microfilaments, intermediate filaments, and microtubules, providing support and shape.

Cell Wall:
- A rigid outer layer providing structural support and protection, primarily composed of cellulose.
Chloroplasts:
- Organelles where photosynthesis occurs, containing chlorophyll and surrounded by a double membrane.
Central Vacuole:
- A large storage organelle that helps maintain cell turgor pressure.

Metabolism:
- Encompasses all chemical reactions in a cell, including catabolism (breaking down molecules) and anabolism (building up molecules).
Homeostasis:
- The process of maintaining stable internal conditions in the cell, despite external environmental changes.
Cell Communication:
- Involves direct contact or signaling through chemicals such as hormones and neurotransmitters.
Reproduction:
- Mitosis: Cell division yielding two identical daughter cells.
- Meiosis: Cell division used to produce gametes, resulting in cells with half the chromosome number.

Passive Transport:
- Movement of substances across the cell membrane without energy input, exemplified by diffusion and osmosis.
Active Transport:
- Requires energy to move substances against their concentration gradient, such as through the sodium-potassium pump.
Endocytosis/Exocytosis:
- Endocytosis: The process by which cells engulf materials.
- Exocytosis: The mechanism used to expel materials from the cell.