introduction Flashcards
what is the waxy cuticle
a thin protective layer above the upper epidermis
what is the waxy cuticle purpose?
to reduce water lost from the leaf
what happens to the waxy cuticle in arid conditions
can become quite thick
what is the purpose of the upper epidermis?
transparent layer which allows as much light as possible to reach the [photosynthesising cells in the leaf
do epidermis cells contain chloroplasts?
no
what does the epidermis form?
layer on the upper and lower surfaces of the leaf
how closley packed are the cells in the spongy mesophyll layer compared to cells in the paliside mesophyll layer
not as closley packed
what does the arrangment of the cells in the spongy mesophyll layer mean for gas exchange?
creates air spaces inside the leaf to enable gasses to move in and out
are there many chloroplasts in the spongy mesophyll cells as there are in the paliside mepophyll layer
no, there are less in spongy mesophyll cells
what is the vascular bundle?
a set of tissues needed to transport vital substances to and from the leaf during photosynthesis
what does the xylem consist of?what does it do?
hollow tubes made from dead cells which brings water up from the roots
what does the phloem consist of?what does it do?
tubes of living tissue with sieve tubes every so often, therefor it takes away sugars made during photosynthesis by the chloroplasts to places where energy is needed
what do stomata allow?
gasses to diffuse in and out of leaves
what type of cells are guard cells?
epidermis cells
what are the only epidermis cells that contain chloroplasts?
guard cells
what are grana?
stacks of up to 100 disk-structure called thylakoids
where does the light -dependent stage of photosynthesis take place?
thylakoid
what do thylakoids contain?
chlorophyll
what are a intergrana lamellae
tubular extensions off of thylakoids that join thylakoids in adjacent grana
what is a stroma?
fluid filled matrix
where does the light-independent stage take place?
stroma
where are starch grains found?
stroma
what is the thylakoid membrane structure to function?
provide a large surface area for the attachment of chlorophyll,electron carriers and enzymes
what do the proteins in the grana do?
hold the chloroplasts in a precise manner that allows maximum absorption of light
granal membranes structure to function
have ATP synthase channels which catalyse the production of ATP,
selectivley permable to create a protein gradient
chroplasts structure to function
contain DNA and ribosomes
so can quickly manufacture some of the proteins involved in the light dependent reaction
