plant cell Flashcards
what does the plant cell consist of?
a plasma membrane interior to the cell wall, hydrophilic on the inside and hydrophobic on the outside
primary vs secondary cell wall
primary cell wall is produced first, secondary produced after, consists of lignin and cellulose
both have pectin and cellulose
middle lamella function
holds cells together
what is plant tissue made of?
mostly cellulose formed from plasma membrane
what are microfibrils composed of?
many cellulose molecules
cellulose microfibril orientation
parallel to each other with rosettes (produce celluose microfibrils) parallel to microtubules
plasmodesmata
intercellular pores connecting adjacent cells, important for cell signaling and defense
what is contained in some plant cell tissue areas?
has microbes and fungi in small spaces
desmotubules
traverse cell membrane
central vacuole
very large, take up water, push against cell wall surface, hold pigments and can account for 90% of cells volume
tonoplast
membrane of central vacuole
central vacuole functions
turgidity, storage, digestion by enzymes
turgidity
provides structure and flower movement
what does the central vacuole store?
water/salts/ions, pigments, starch proteins, waste/toxins
function of digestive enzymes of central vacuole
breakdown of macromolecules, comparable to lysozymes in animal cells
druses
aggregates of calcium oxalate crystals
rawhides
needle like crystals of calcium oxalate
plants in hypertonic, isotonic, and hypotonic environments
hypertonic - cells are plasmolyzed and water moves out
isotonic - cells are flaccid and water moves in and out equally
hypotonic - water moves in and cells are turgid, making the plant erect
plastid development
proplastid develops into chloroplast or store pigment to become chromoplast, or store starch to become amyloplast
thylakoid membrane
found in the chloroplast, includes protein complexes important for photosynthesis
do chloroplasts need light?
Yes, but not too much.
chromoplasts in bright vs dim light
they will orient differently
leucoplasts
non pigmented plastids - include amyloplasts which store starch, and elaioplasts which store lipids
function of pigment stores in plastids
give color