2.5 Ultrastructure of Plant Cells Flashcards
1
Q
What surrounds the plasma membrane of a plant cell?
A
Cell wall
2
Q
What are cell walls made up of?
A
Cellulose
3
Q
What is the function of the cell wall?
A
- Freely permeable so substances can move into and out of the cell
- Gives the cell its shape - cell’s contents press against the cell wall making it rigid, which supports the cell and plant as a whole
- Acts as defense mechanism vs invading pathogens
4
Q
What is a vacuole?
A
Membrane lined sac in the cytoplasm containing cell sap
5
Q
What is the function of vacuoles?
A
Maintain turgor so that the cell’s contents push against the cell wall and maintain a rigid framework
6
Q
What is the tonoplast?
A
Membrane surrounding the vacuole
7
Q
What is the function of the tonoplast?
A
Selectively permeable - small molecules can pass but others can’t
8
Q
Describe the structure of chloroplasts
A
- Double membrane
- Fluid inside - stroma
- Internal network of membranes which forms thylakoids - flattened sacs
- Several stacked thylakoids = granum
- Grana joined by lamellae - membranes
- Grana contain chlorophyll - where light-independent reactions occur
- Contains starch grains - starch produced from PS
- Contain DNA + ribosomes
9
Q
What is the function of chloroplasts?
A
- Site of photosynthesis
* Can produce its own proteins
