L3, The Plant Cell Flashcards
plants can produce gametes by …
mitosis - unlike animals
what are the three primary features that distinguish a plant from an animal cells
plastids, vacuole, cell wall
what are mitochondria and plastids remnants of?
endosymbiosis
how many membranes do plastids have?
two layers
where are plastids inherited from?
the egg cell - maternal inheritance
characteristics of a plastid:
they have their own DNA,
semi-autonomous (synthesize some but not all proteins needed for function), cytoplasmic inheritance
what are the common types of plastids
chloroplasts, chromoplasts, leucoplasts
what are the sites of photosynthesis
thylakoid, stroma, pigments, carotenoids
what are the two main components of the chloroplast
thylakoid and grana
what are thylakoids?
membrane bound compartment inside the chloroplast, where pigments are embedded in membrane
what are grana?
stack of thylakoid membranes, interconnected by stroma thylakoid that act as the light reactions of photosynthesis
what do actin filaments do?
connect organelles (chloroplasts) together?
what do myosin molecules do?
pull chloroplasts along actin filaments
what is cytoplasmic streaming and how is it induced?
flow of the cytoplasm in the cell - induced by changes in temperature, light, and pH
what are chromoplasts?
pigmented plastids
what are characteristics of chromoplasts?
no chlorophyll, contain carotenoid pigments, shield against UV, attract pollinators/ seed dispersal, protect against biotic attack, several are important vitamins for humans
what are leucoplasts?
a less differentiated version of the mature plastids - no pigments or internal membranes, and serve as storage organelles
where do all plastids come from?
proplastids
as a tomato ripens, what transforms into what?
chloroplasts transform into chromoplasts
what pigment do chromoplasts contain?
lycopene - red color, nutritionally important
what are chloroplasts
a complex internal membrane system which consist of thylakoid and grana, and contain chlorophyll and sometimes carotenoids, and function as the site of light reactions of photosynthesis
chloroplasts are the most differentiated of plastids
what are chromoplasts?
less complex internal membrane system that contain carotenoid pigments
what are leucoplasts?
plastids that contain no internal membrane structure or pigments, they are the least-differentiated plastid and store starch (amyloplasts) and oils
what is the structure of vacuoles?
single-membrane tonoplast, filled with cell sap, usually the largest component of the plant cell
what are the functions of vacuoles?
provide rigidity using turgor and hydrostatic pressure, store nutrients and other chemicals, and break down complex molecules
how do vacuoles obtain nutrients and chemicals to be stored for later?
contain channels in their membranes (diffusion), transporters, pumps, and vesicle-mediated mode of transport - they acquire their compounds from the cytoplasm and other organelles
how is turgor pressure created?
by water molecules in the vacuole
what kind of pressure do ions and sugars create?
osmotic pressure
how does nicotine biosynthesis protect tobacco plants?
nicotine is exported to the leaf where the chemical is stored in leaf vacuoles. a high concentration develops which deters herbivory
what does vacuole storage allow?
compartmentalization and quick release upon damage
what are pigments in petals linked to?
pollination and seed dispersal
what pigments do the Calibrachoa flower contain?
pink anthocyanins in the petals, orange carotenoids in the petal, and another pigment anthered by saffron
what can cause a change in pigment?
change in vacuolar pH
what flower experiences a pigment change as it grows?
japanese morning glory - color changes from buds to flowers. as the flowers grow, the ph increases from 7 to 7.7 (purple to blue)
part of breaking down complex molecules in the vacuole includes…
recycling organelles
recycling organelles in the vacuole of plant cells is known as…
autophagy
what are two factors that help facilitate autophagy?
low pH and catalytic process
what are bulbs?
short stem with fleshy leaves or leaf bases
function as food storage organs during dormancy
vegetative reproduction depends on this process
what are bulb tissues mainly made of?
vacuoles
