TOPIC B4 BIOENERGETICS Flashcards
what does photosynthesis do
-uses energy to change carbon dioxide and water into glucose and oxygen
where does photosynthesis take place
-in chloroplasts in green plant cells
-contain pigments like chlorophyll which absorb light
is photosynthesis exo or endothermic, what does this outcome mean
-endothermic
-means energys transferred from the environment in a process
word equation for photosynthesis
carbon dioxide + water—(light)—— glucose +oxygen
6CO2 + 6H2O __LIGHT) C6H12O6 + 6O2
state why plants use glucose
-for respiration
-making cellulose
-making amino acids
what factors affect the rate of photosynthesis
-intensity of light
-concentration of CO2 and temperature
e.g
-at night, light is the limiting factor
-in winter, temperature
-warm and bright enough, amount of CO2 is usually limiting
state the affect of the amount of chlorophyll
in a plant it is affected by disease or environmental stress, such as a lack of nutrients
-these factors cause chloroplasts to become damaged
state why not enough light slows down the rate of photosynthesis
-light provides energy needed for photosynthesis
-as light level raises, photosynthesis increases steadily
-as light goes up, the rate no longer increases
explain the affect low carbon dioxide concentration has on the rate of photosynthesis
-raw material for photosynthesis
-after the graph flattens out, the rate no longer increases
why does temperature have to be just right for photosynthesis
-if too low, enzymes needed work more slowly
-if too hot, enzymes will be damaged
-happens at 45degrees
how to show the effect of limiting factors
by using a graph to show
state the inverse square law
light intensity= 1
DIVIDED BY
distance (d)squared
what does light intensity and distance increase for the inverse square law link
as distance increases, light intensity decreases
theyre inversley proportional to each other
state the most common environment to grow plants and why
a greenhouse
-as they trap the sun’s heat and make sure temperature doesn’t become limiting
-in winter they use a heater
-in summer they use shades
-supply artifical light
-enclosed keeps them away from pests
respiration definiton
is it exo or endothermic
the process of breaking down glucose to transfer energy which occurs in every cell
exothermic
