Untitled Deck Flashcards
(57 cards)
What is a key feature distinguishing prokaryotic cells from eukaryotic cells regarding the nucleus?
Prokaryotic cells have no nucleus (DNA in nucloid); eukaryotic cells have a nucleus.
Prokaryotic cells include bacteria and archaea, while eukaryotic cells include animals, plants, and fungi.
How is the DNA structured in prokaryotic cells compared to eukaryotic cells?
Prokaryotic DNA is circular and lacks histones; eukaryotic DNA is linear and associated with histones.
What is the typical size range for prokaryotic cells?
Small (1–10 µm)
What process do prokaryotic cells use for cell division?
Binary fission
What are the main functions of the nucleus in a cell?
Stores genetic material (DNA); coordinates activities like growth, metabolism, and reproduction.
Where are ribosomes located and what is their primary function?
Ribosomes are free in the cytoplasm or bound to rough ER; they synthesize proteins.
What is the role of the Golgi apparatus in a cell?
Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.
What is the primary function of mitochondria?
Produces ATP through cellular respiration.
Which organelle is responsible for digesting waste and damaged organelles?
Lysosomes
What is the function of peroxisomes in a cell?
Break down fatty acids and toxic substances using oxidative enzymes.
Describe the role of the cytoskeleton.
Provides cell structure, enables movement, intracellular transport, and cell division.
What is the structure of the plasma membrane?
Phospholipid bilayer with proteins.
What type of transport proteins change shape to move molecules across membranes?
Transporter proteins (carriers)
What are the three types of membrane transporters?
- Uniporters
- Symporters
- Antiporters
What is the primary function of receptor proteins?
Detect chemical signals and trigger cellular responses.
What distinguishes tight junctions from other types of cell junctions?
They create a seal between adjacent cells and prevent leakage of molecules.
What is the function of desmosomes?
Provide strong adhesion between cells and resist mechanical stress.
What is the primary difference between passive and active transport?
Passive transport does not require energy; active transport requires energy (ATP).
Define simple diffusion.
Movement of small, nonpolar molecules directly across the membrane from high to low concentration.
What is osmosis?
The diffusion of water across a semi-permeable membrane from low solute concentration to high solute concentration.
What is the definition of homeostasis?
The body’s ability to maintain a stable internal environment despite changes in external conditions.
What are the components of homeostatic regulation?
- Sensor (Receptor)
- Control Center
- Effector
What is the primary role of negative feedback in homeostasis?
Reverses a change to bring it back to normal.
What is the effect of a hypotonic solution on a cell?
Water moves into the cell; the cell swells.