The Plant Cell Flashcards
What are the unique features of a plant cell compared to an animal cell ?
- The cell wall
- Plastids
- The Vacuole
What are the 4 function of plant cell wall ?
- Maintain and determine cell shape
- Development of specialised cells and function
– Controls rate and direction of growth
- Protects against pathogens, environment
What 3 layers is the plant cell wall made up of ?
- Hemicellulose
- Cellulose
- pectin
Why are enzymes in the cell wall required ?
Cell wall enzymes are required to break connections to allow the cell wall to expand so new materials can be deposited around the cell wall
What is the ripening of fruit associated with ?
The changing in cell wall structure and composition
Whats a secondary cell wall and function ?
Once a cell wall stops expanding, a secondary wall is deposited between the primary wall and the plasma membrane
- supports, strengthens, protects
Whats secondary thickening made out of ?
- Cutin
- Lignin
- cellulose
- Suberin
Where does the specific secondary thickening occur ?
In the endodermis layer in the anther
What is an abscission ?
-Process to remove organs
-Protective layer forms around the abscission zone
-Middle lamella between the cells is digested to remove the unwanted organ
What is a root hair cell and what’s its function ?
-A root hair compromise’s a single cell and originates from the epidermis
- Increases surface area of the root
- Thin cell wall to facilitate uptake of water and nutrients
What does the root cap act as ?
Root cap acts to protect, lubricate and guide the root in response to gravity.
What does the xylem do and how is it specialised ?
-Xylem conducts water passively
-All xylem cells are elongated cells with secondary cell walls that die at maturity
What is the function of a phleom and structure ?
- Phleom actively transports sugars and amino acids
- Translocation occurs in both directions - Cross sections between the cells are perforated forming sieve plates
- Cells are living and a they mature they lose their organelles
Whats a companion cell and how is it different plant cell ?
Is similar to a normal cell but contains
- plasmodesmata to the phloem sieve tube cell
- extra ribosome and mitochondria
- supports the sieve tube cell
Whats a trichome ?
- Small hair growing from the epidermis
- Unicellular or multicellular
- branched or unbranched
What are the 5 different plastids ?
- CHROMOPLASTS - Pigment synthesis and storage
- LEUCOPLAST - Store a variety of energy sources
- ElAIOPLAST - Storage of lipids
- PROTEINOPLAST - Proteins storage
- AMYLOPLAST - Synthesis and storage of starch
What is the structure of a chloroplast?
- Contains genetic material plus protein synthesis machinery
- Thylakoids, membranous sacs are stacked to form granum
- Stroma is the internal fluid
What occurs at the grand and stroma ?
GRANA - Membranes where the light reactions take place
STROMA - Soluble matrix where co2 fixation takes place
What is the structure of vacuole ?
1- Vacuoles are membrane bound organelles filled with cell sap
2. may comprise the majority of the volume of a mature cell
3. Contain fluid often at an acidic ph - pigments
What are the 4 roles of a vacuole ?
- General cell homeostasis
- Maintaining turgor pressure
- Detoxification
- Storage tissues
