Chapter 4 Flashcards
What are Pectins
Very diverse group of branched hydrophilic Polysaccharides
What is the plant cell protoplast?
Everything enclosed by the plasma membrane
What are the two defined areas within the protoplast
Nucleus and Cytoplasm
What are two universal functions of the plasma membrane?
- Mediate transport of substances in/out of the cell
2. Transduces hormonal and environmental signals
What are two plant cell specific functions of the plasma membrane?
- Coordinates synthesis and assembly of cell wall
2.
What are Plasmodesmata?
Narrow cytoplasmic channel connecting adjacent plant cells
Creates a physically continuous plasma membrane
What is the endomembrane system of a plant cell?
Connects to every organelle and connects every adjacent plant cell within a symplasm
Where does oil accumulate in the endomembrane system? What protein is associated?
Between the two lipid mono layers of the ER and bud to form oil bodies. Oleosin
Rough ER
Protein synthesis- sucrose synthase and cellulose enzymes
Golgi
Carbohydrate synthesis-Sucrose. Protein Glycosylation
Plasma Membrane
Cellulose and Callose synthesis
What is the proposed mechanism of wax biosynthesis to produce the cuticle?
Fatty acid precursors are transported to the cell wall from the smooth ER to the plasma membrane
Flippase transfers FAs to outer mono layer
What is the plant cell vacuole?
Fluid filled compartments enclosed by a single membrane
Can occupy 30-90% of the cell volume
Short and long term storage
What are Plastids?
Semi-autonomous organelles
Inheritance is species specific
What are proplastids?
Small colorless plastids in undifferentiated meristematic tissue
Double membrane, thylakoids, and starch accumulation
What are chloroplasts?
Sites of photosynthesis
Nucleoid - chloroplast chromosome
Pigments- chlorophyll and carotenoid
What are Plastid Stromules
Connection between plastids
Plastid symplast network
Swap proteins and other compounds
What are etioplasts?
Develop from proplastids in the absence of light
Accumulate a paracrystaline prolamellar body made of membrane lipids the chlorophyll precursor
What are chromoplasts?
Found in dark grown seedlings
Poised to make a chloroplast
Prolamellar body
Store carotenoids
What are amyloplasts?
Starch storage
What is a Leucoplast?
Colorless plastids
Productive and storage of organic compounds- volatile compounds produced by trichomes, nectaires, and secretory cavities
What are Gerontoplasts?
Plastids in senescing tissues
Often resemble chromoplasts and accumulate carotenoids
What are Peroxisomes?
Micro bodies
Green leaves -removes of H2O2 and Glycolic acid metabolism associated with photorespiration
Endosperm of Cotyledons - converts fats to usable carbohydrates in germinating seeds
What are the functions of the cell wall?
Environmental interface Cell-cell recognition Apoplastic transfer Defense Signaling and communication
