Cell Biology, Cell Membrane, and Transport Flashcards

Practice flashcards in question and answer format covering cell structures, organelles, cell membrane transport mechanisms, and tonicity.

What is the cell membrane made of, and what are the two parts of a phospholipid?

The cell membrane is made of a phospholipid bilayer (2 layers). Each phospholipid has a hydrophilic (water-loving) head and a hydrophobic (water-fearing) tail.

What does the cell membrane control, and what functions do its proteins serve?

It controls what enters and leaves the cell. It has proteins that act as receptors, carriers, and identification markers.

What is the job of the nucleus?

It holds the DNA and controls the cell.

What is the job of the mitochondria?

Mitochondria make energy in the form of ATP.

What is the job of ribosomes?

Ribosomes make proteins.

What is the difference between rough ER and smooth ER?

Rough ER (with ribosomes) makes proteins for export. Smooth ER (no ribosomes) makes lipids/fats.

What is the job of the Golgi apparatus?

The Golgi apparatus packages and ships proteins.

What is the job of lysosomes?

Lysosomes are responsible for digestion and cleanup — they break down waste.

What is the job of peroxisomes?

Peroxisomes carry out chemical reactions that break down fats and toxins.

What is the job of vesicles?

Vesicles are responsible for the storage and transport of materials inside the cell.

What is the difference between cilia and flagella?

Cilia are short and numerous and move material across the cell surface. Flagella are longer and usually few and move the whole cell (example: a sperm tail is a flagellum).

What is passive transport, and what are its 4 types?

Passive transport needs NO cellular energy and moves substances from high concentration to low concentration unless energy is used. Its 4 types are simple diffusion, facilitated diffusion, osmosis, and filtration.

What is simple diffusion?

Simple diffusion is when substances move from high concentration to low concentration, straight through the membrane, using no energy.

What is facilitated diffusion?

Facilitated diffusion is movement from high concentration to low concentration requiring no energy, but using a protein carrier/channel to help substances cross.

What is osmosis?

Osmosis is the movement of water across a membrane, from high water concentration to low water concentration.

What is filtration?

Filtration is the movement of substances caused by pressure, not by concentration.

In a hypotonic solution, what happens to water and the cell?

Water goes INTO the cell, so the cell swells and may burst (hypo = low solute outside = water rushes in).

In a hypertonic solution, what happens to water and the cell?

Water goes OUT of the cell, so the cell shrinks/crenates (hyper = high solute outside = water leaves).

In an isotonic solution, what happens to water and the cell?

Water moves in and out equally — there is no net change in the cell.

What is tonicity?

Tonicity is the ability of a solution to cause a cell to gain or lose water. It depends on the concentration of solutes compared to the cell.