Cell Coverings Flashcards
(34 cards)
What are the functions of cell coverings?
- Species identification
- Protections against dessication, pathogens, predators.
- Barrier between cell and environment: osmotic balance, uptake, secretion/excretion
What are the 4 types of cell coverings?
- Cell membrane
- Membrane + Extracellular material
- Membrane + Intracellular material
- Membrane + Extra- and Intracellular material
What has a plasmodia cell plasma membrane?
Chlorarachniophyte (Rhizaria: Cercozoa)
What only uses a plasma membrane?
Many Chrysophyceae (Chromalveolates: Heterokontophyta)
What extra / intra cellular material does a Cryptophyta use? (Chromalveolates)
A periplast.
- Inner=protein fibrils in sheets or plates
- Outer=plates, scales, mucilage, combo
How much pressure does it take to break a pellicle?
200 psi
What has a pellicle?
Euglenophyta (Excavata: Euglenozoa)
What is a PS?
Pellicular strip
What cell covering does a euglenophyta utilize?
- Pellicle
- Mucilage coating over pm
- Organized fibers
- Microtubular system
What are mucilages and sheaths?
- Gelatinous, hold filaments or colonies together.
- Exopolysaccharides
- Can collect pigments or metal salts
What utilizes mucilages and sheaths?
- Cyanobacteria
- Some Cryptophyta (Chromalveolates)
- Euglenophyta (Excavta: Euglenozoa)
- Chlorophyta (Plantae)
- Chrysophyceae (Chromalveolates: Heterokontophyta)
What kind of scales do heterokontophyta have?
Silica on glycoprotein matrix.
What kind of scales do haptophyta have?
Calcium carbonate on organic matrix.
What kind of scales do chlorophyta have?
Organic (polysaccharide), non-mineralized.
Describe the scales of chlorophyta, prasinophyceae.
- Unmineralized (acidic polysaccharides)
- Often multiple laters of different shapes.
- Synthesized in golgi then exocytosed.
Describe the scales of heterokontophyta, Synurophyceae
- Silica scales, often elaborate
- Produced internally in deposition vesicles, part of E.R.
- Fuse with Golgi vesicles and move to surface.
Describe the scales of a haptophyta.
- Unmineralized
- Calcified (coccoliths)
- Organic base plate synthesized in Golgi
What is the difference between heterococcoliths and holococcoliths?
Heterococcoliths: Organic base plate synthesized in golgi and calcified within golgi.
Holococcoliths: Organic base plate synthesized in golgi and calcified on cell surface.
Describe the frustules of Heterokontophyta, Bacillariophyceae
- Only in diatoms
- Amorphous hydrated silica
- Produced internally in silica deposition vesicles, derived from Golgi
- Organic layer in between plasma membrane and frustule.
Describe the structure of a diatom.
The epitheca fits on top of the hypotheca.
Other words for pore.
- Hole
- Areola
- Puncta (Punctae)
What is stria (striae)?
A row of punctae.
Centric diatoms are symmetrical around ______ access.
Radial.
Pennate diatoms are symmetrical around ______ line.
Apical.
