Zusammenfassung der Ressource
Photosynthesis
- 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?
- YES: it's Matthew
- NO: continue...
- Q3: is the person
clearly visible?
- YES: it's Lewis
- NO: it's Ian, in
super sneaky
ninja stealth mode