Knowt Flashcard Set – Cells: The Living Units

A set of Q&A flashcards covering cell biology topics including cell structure, transport, cell signaling, and basic genetics.

What is the plasma membrane's main role?

Acts as the cell’s boundary, controlling what enters/exits.

What organelle makes ATP?

Mitochondria.

Which organelle is the post office of the cell?

Golgi apparatus.

Function of ribosomes?

Protein synthesis.

Difference between rough ER and smooth ER?

Rough ER makes proteins (with ribosomes); smooth ER makes lipids & detoxifies.

Function of lysosomes vs. peroxisomes?

Lysosomes digest/recycle; peroxisomes detoxify chemicals.

What does the cytoskeleton do?

Provides shape, support, movement.

What are centrioles for?

Help organize cell division.

Integral vs. peripheral proteins?

Integral span membrane; peripheral sit on the surface.

Tight junctions function?

Form seals between cells to prevent leakage.

Desmosomes function?

Anchor cells like Velcro.

Gap junctions function?

Allow communication between cells.

What is simple diffusion?

Movement from high → low concentration without energy.

What is facilitated diffusion?

Passive transport with protein help.

Osmosis definition?

Movement of water across a membrane.

Filtration definition?

Movement due to pressure (like kidney filters).

Active transport definition?

Movement against concentration gradient using ATP.

Movement against concentration gradient using ATP.

Active transport.

Phagocytosis vs. pinocytosis?

Phagocytosis = eating solids; pinocytosis = drinking fluids.

Receptor-mediated endocytosis?

Specific uptake via receptors.

Exocytosis?

Vesicles releasing substances out of the cell.

Hypotonic solution effect on RBC?

Swells/bursts.

Isotonic solution effect on RBC?

Normal.

Hypertonic solution effect on RBC?

Shrivels.

What maintains resting membrane potential?

Ion distribution + Na+/K+ pump.

Phases of the cell cycle?

Interphase (G1, S, G2), mitosis (PMAT), cytokinesis.

What is DNA replication?

Copying DNA before cell division.

What is transcription?

DNA → mRNA (nucleus).

What is translation?

mRNA → protein (ribosome).

Role of mRNA?

Carries instructions from DNA.

Role of tRNA?

Brings amino acids during protein synthesis.

Role of rRNA?

Structural part of ribosome.

What is a gene?

DNA segment coding for a protein.

What is the genetic code?

Set of codons that specify amino acids in proteins.