Flashcards in The Cell Deck (26)
What is the structural hierarchy in a multicellular animal?
Atom > Simple Molecules > Macromolecules > Membranes > Organelles > Cells > Tissues > Organs > Organ Systems > Animal
What are the major differences between prokaryotes and eukaryotes?
Prokaryotes have no true nucleus and organelles. Their genetic information freely floats around the cell. Their structure is simple.
Eukaryotes have a true nucleus and organelles. Their genetic information is stored inside the nucleus. Their structure is more complex.
What does the plasma membrane's semi-permeability mean?
It only allows certain molecules to pass through.
What does the nucleus do?
It directs all the cell's activities and contains the chromosomes.
What does the nucleolus do?
It is an assembly area of ribosomes.
What is the main function of ribosomes?
This accounts for more than half of the total membrane responsible for protein and lipid synthesis.
What does the smooth endoplasmic reticulum do?
What does the rough endoplasmic reticulum do?
Process and synthesize proteins
What are the functions of the golgi apparatus?
Modifies the products of the endoplasmic reticulum, produces macromolecules, sorts and packs materials into transport vesicles
Why are lysosomes considered the "suicide bags" of the cell?
They contain hydrolytic enzymes to digest macromolecules. They can phagocytize another cell or undergo autophagy and are capable of self-destruction.
What are cell vacuoles?
Diverse maintenance compartments, storage of molecules and water
A system of fibers ranging all over the cytoplasm responsible for anchorage, structure and shape of the cell, and assists in the process of motility.
What do tight junctions do?
Prevent leakage of extracellular fluid of neighboring cells by pressing together
What do desmosomes or anchoring junctions do?
Attach cells together into strong sheets
What do gap or communication junctions do?
Offer cytoplasmic channels between neighboring cells for direct communication
Membrane carbohydrates covalently bonded to lipids
Membrane carbohydrates that bind to proteins
What is osmosis?
Diffusion of water across a selectively permeable membrane from a region of lower solute concentration to a region of higher solute concentration
What is tonicity?
The ability of a solution to cause a cell to gain or lose water
What happens to a cell in an isotonic solution?
Nothing. There is no net movement of water in or out of the cell.
What happens to a cell in a hypotonic solution?
The cell will burst (lysis) due to the movement of water from outside the cell to the inside.
Why does a cell burst in a hypotonic solution?
The cell cannot withstand the osmotic pressure from the solution.
What happens to a cell in a hypertonic solution?
The cell will shrink due the movement of water from inside the cell to the outside.
Differentiate exocytosis and endocytosis.
Exocytosis occurs when vesicles move towards the cell membrane, attach to it, then discharge its contents outside the cell.
Endocytosis occurs when the cell engulfs large molecules, forming vesicles.