Cell Biology Quiz - Cell Theory and Types

Prokaryotic Cells
- Lack a nucleus and membrane-bound organelles.
- Examples: Bacteria and Archaea.
- DNA is circular and located in the nucleoid region.
Eukaryotic Cells
- Contain a nucleus and membrane-bound organelles.
- Examples: Plant cells, animal cells, fungi, and protists.
- DNA is linear and organized into chromosomes.

Plasma Membrane
- Semi-permeable barrier that controls the movement of substances in and out of the cell.
Cytoplasm
- Jelly-like substance where cellular processes occur.
Nucleus
- Contains genetic material (DNA) and controls cellular activities.
Mitochondria
- Powerhouse of the cell; site of ATP (energy) production through cellular respiration.
Ribosomes
- Sites of protein synthesis; can be free-floating or attached to the endoplasmic reticulum.
Endoplasmic Reticulum (ER)
- Rough ER: Studded with ribosomes; involved in protein synthesis and processing.
- 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 to breakdown waste materials and cellular debris.
Chloroplasts (in plant cells)
- Site of photosynthesis; contains chlorophyll.
Cell Wall (in plant cells)
- Provides structure and protection; made of cellulose.

Cell Division
- Mitosis: Process of cell division resulting in two identical daughter cells.
- Meiosis: Process of cell division that produces gametes (sperm and egg) with half the number of chromosomes.
Cellular Respiration
- Process by which cells convert glucose and oxygen into ATP, carbon dioxide, and water.
Photosynthesis (in plants)
- Conversion of light energy into chemical energy stored in glucose, occurring in chloroplasts.

Cells communicate through signaling molecules, receptors, and cell junctions.
Processes include:
- Autocrine signaling: Cell signals to itself.
- Paracrine signaling: Signals to nearby cells.
- Endocrine signaling: Hormones released into the bloodstream affecting distant cells.

Passive Transport
- Movement of molecules across the membrane without energy input (e.g., diffusion, osmosis).
Active Transport
- Movement of molecules against their concentration gradient requiring energy (e.g., sodium-potassium pump).
Endocytosis and Exocytosis
- Endocytosis: Process of taking substances into the cell by engulfing them.
- Exocytosis: Process of exporting materials out of the cell.

Involves a series of molecular events triggered by receptor activation leading to a cellular response.
Key components include:
- Ligands: Signaling molecules.
- Receptors: Proteins that bind ligands.
- Second messengers: Molecules that relay signals from receptors to target molecules inside the cell.

Prokaryotic Cells
- Do not have a nucleus or membrane-bound organelles; found in bacteria and archaea.
- DNA is circular and resides in the nucleoid region.
Eukaryotic Cells
- Characterized by the presence of a nucleus and membrane-bound organelles; includes plant, animal, fungi, and protist cells.
- DNA is linear, organized into chromosomes.

Plasma Membrane
- Acts as a semi-permeable barrier regulating substance movement in and out of cells.
Cytoplasm
- Jelly-like fluid where various cellular activities take place.
Nucleus
- Houses genetic material (DNA) and regulates cell functions.
Mitochondria
- Known as the powerhouse of the cell, where ATP is produced via cellular respiration.
Ribosomes
- Sites for protein synthesis, can be found free-floating or attached to the endoplasmic reticulum.
Endoplasmic Reticulum (ER)
- Rough ER is embedded with ribosomes; associated with protein synthesis and processing.
- Smooth ER lacks ribosomes; involved in lipid synthesis and detoxification processes.
Golgi Apparatus
- Modifies, sorts, and packages proteins and lipids for secretion or transport to other organelles.
Lysosomes
- Contain enzymes for digesting waste materials and cellular debris.
Chloroplasts (specific to plant cells)
- Sites for photosynthesis, containing chlorophyll for energy capture.
Cell Wall (specific to plant cells)
- Provides structural support and protection, primarily composed of cellulose.

Cell Division
- Mitosis creates two identical daughter cells.
- Meiosis produces gametes with half the chromosome number.
Cellular Respiration
- Converts glucose and oxygen into ATP, carbon dioxide, and water.
Photosynthesis (specific to plants)
- Transforms light energy into chemical energy, producing glucose in chloroplasts.

Cells use signaling molecules, receptors, and junctions to communicate.
Types of signaling include:
- Autocrine: The cell signals itself.
- Paracrine: Signals are sent to neighboring cells.
- Endocrine: Hormones affect distant cells through the bloodstream.

Passive Transport
- Involves molecule movement across membranes without energy use (e.g., diffusion and osmosis).
Active Transport
- Requires energy to move molecules against their concentration gradient (e.g., sodium-potassium pump).
Endocytosis and Exocytosis
- Endocytosis: Cell engulfs substances to bring them inside.
- Exocytosis: Exports materials out of the cell.

A series of biochemical events initiated by receptor activation that leads to a specific cellular response.
Key components include:
- Ligands: Signaling molecules.
- Receptors: Proteins that interact with ligands.
- Second messengers: Convey signals from receptors to target molecules within the cell.