Ultrastructure of Plant Cells Flashcards
What are plant cell walls made up of?
Cellulose
What type of permeability do plant cell walls have?
Freely permeable - substances can pass in and out of the cell wall
What determines the shape of a plant cell?
Cell wall
How does the cell wall support the plant cell and plant as a whole?
Contents of the cell press against the cell wall, making it rigid
What type of mechanism does the cell wall act as? Elaborate.
The cell wall acts as a defense mechanism - protecting the contents of the cell against pathogens
What’s the main structural difference between animal cells and plant cells?
Plant cells are rigid
Define vacuole
Membranous sac used to transport materials in the cell
What is the function of vacuoles?
Maintenance of turgor - so that the contents of the cell push against the cell wall, maintaining a rigid framework
What is the membrane of a vacuole called?
Tonoplast
What type of permeability does the tonoplast have? What does this mean?
Selectively permeable - some molecules can pass but others can’t
Define chloroplasts
Organelles responsible for photosynthesis in plant cells.
They contain chlorophyll pigments, which are the site of light reactions in photosynthesis
Do chloroplasts have a single membrane or double membrane?
Double membrane
What is the fluid inside chloroplasts called?
Stroma - fluid interior of chloroplasts
What does the internal network of membranes inside chloroplasts form?
Flattened sacs called thylakoids
Define what a granum is
Structure inside chloroplasts composed of a stack of several thylakoids.
