Photosynthesis is a series of chemical
reactions that USES ENERGY from
SUNLIGHT to PRODUCE FOOD
the food that's produced is GLUCOSE,
a sugar with a multiplicity of uses...
RESPIRATION
plants use some of da glucose for
respiration (NOT BREATHING!), which
releases energy from the glucose
to make CHEMICALS to
HELP THE PLANT GROW
glucose can be converted into
cellulose for making cell walls,
indeededly so in a rapidly growing plant
glucose can also be combined with
nitrogen (from nitrates taken up from the
soil by plant roots) to make amino acids,
which are then made into proteins
glucose is
also used to
help make
chlorophyll
STORED
AS STARCH
glucose can be turned into starch and
stored in roots, stems and leaves,
being used at times when the rate of
photosynthesis is slower, like in winter
photosynthesis happens in the cells in
green parts of plants, eg. leaf cells and
some microorganisms, eg. phytoplankton
organisms that photsynthesise are at the start of food
chains, making the energy from the Sun available to other
organisms by converting it into glucose and passing it down
along the food chain when the organisms are eatened
it's a green substance, found in the
chloroplasts in animal cells, which ABSORBS
SUNLIGHT and allows the energy to be used to
convert carbon dioxide and water into glucose
chlorophyll is
needed for
photosynthesis
to happen
as evidenced in the exquisitely plagiarised diagram
to the bottom of me (hehe! bottom!), oxygen is
produced as a waste product of photosynthesis,
which is actually rather helpful for polluting humans.
RATE OF PHOTOSYNTHESIS
the
is affected by three environmental factors...
AMOUNT
OF CARBON
DIOXIDE
carbon dioxide is one of the raw
materials needed for photosynthesis
and, as with light intensity, as the
amount of carbon dioxide increases
the rate of photosynthesis increases,
up to a cretain point.
if it's warm and bright enough, the amount
of carbon dioxide is usually the limiting
factor for the rate of photosynthesis
TEMPERATURE
when the temperature is the limiting factor
in the rate of photosynthesis it's usually
because it's too low, eg. in winter.
this is because the enzymes needed
for photosynthesis work mooorrreee
sloooowwwlyyy at low temperatures
if the plant gets too hot, the enzymes
it needs for photosynthesis and its
other reactions will be denatured
this happens at about 45°C, which is pretty
toasty outdoors but possible in a greenhouse
AMOUNT OF LIGHT
light provides the energy
needed for photosynthesis,
and so as it is raised, the rate
of photosynthesis increases
steadily up to a certain point
at night the amount of light
is usually a limiting factor on
the rate of photosynthesis
Investigating Photosynthesis
yay imaginary
fieldwork!
TAKING A TRANSECT
transects are a way of
investigating how
something changes
across an area
to set up a transect you run a tape
measure between two set points - simples!
you then start at one end of the transect
and collect the data that you want
and then move along the transect and collect the data again
and again
and again
and again
jusqu'à tu reach the end...voilà!
for example, if one was
to investigate the effect
of coolness on the
distribution of coeliacs,
one could take a
transect across an area
where the coolness
level changes (eg. from
Harston to Hauxton) and
one could collect data
on how the percentage
of people with different
allergies changes
across the transect
STUFF THAT COLLECTS DATA
light meter
a sensor that accurately measures the
levels of light, jolly spiffing when comparing
plants in areas with different areas of light
and similarly minded endeavours
quadrat
a square frame
sometimes divided into
a grid of 100 smaller
squares that can make
data collection quicker,
easier and EXTRA
FUN, eg. you could
estimate the percentage
cover of a plant species
on the ground by
counting howmuch of
the quadrat is covered
by the species - you
count a square si c'est
plus que half-covered
identification key
kinda self
explanatory, an
identification key (like
the one above) is a
series of questions to
work out what
something is - as you
work your way
through the
questions, you narrow
down your options
until you are left with
the right answer
IDENTIFICATION KEY
for identifying the
people in the beautiful
image to our left, taken
in our hotel in Rome
Q1: does the
person have
his eyes open?
YES: it's Callum
NO: continue...
Q2: is the person's
t-shirt choice intended
to annoy the locals?