2.18 - 2. 33B (nutrition) Flashcards
what is the photosynthesis theory
it is an endothermic reaction in which energy from sunlight is transferred to the chloroplasts in green plants
what do plants use the products of photosynthesis for
plants use the products as a source of energy in respiration
they can also use it to
- produce starch for storage
- synthesise lipids for an energy source in seeds
- to form cellulose to make cell walls
- to produce amino acides
what are the raw materials needed for photosynthesis
carbon dioxide and water
what is the word equation for photosynthesis
carbon dioxide + water —-> glucose +
oxygen
and on the arrow there is light and chlorophyll
what are the main limiting factors of photosynthesis
- temperature
- light intensity
- carbon dioxide
what is the balanced chemical equation for photosynthesis
6 CO2 + 6 H2O —-> C6H12O6 + 6 O2
and on the arrow there is light and chlorophyll
what happens to the rate of photosynthesis when the temperature increases
as temp increases, so does the rate of photosynthesis due to an increase in kinetic energy
but once the optimum temperature is reached, any further increase in temp will cause the enzymes to denature
what happens to the rate of photosynthesis when light intensity increases
it has a linear increase until it reaches a certain point and then the rate of photosynthesis remains constant (does not go down)
what happens to the rate of photosynthesis when carbon dioxide concentration increases
it has a linear increase until it reaches a certain point and then the rate of photosynthesis remains constant
what are the main plant tissues in a leaf?
- epidermal
- palisade mesophyll
- spongy mesophyll
- xylem and phloem
what is the upper epidermis in a leaf
- a single layer of transparent cells to allow light through
- covered by a waxy cuticle that prevents water loss
what is the palisade mesophyll in a leaf
- column shaped cells with many chloroplasts
- most photosynthesis
what is the spongy mesophyll in a leaf
- loosely packed cells
- air spaces in between them
- maximise diffusion of gases
what is the lower epidermis in a leaf
- contains guard cells controlling opening and closing of stomata
- found mainly on underside of leaf to reduce water loss
what is the vascular bundle in a leaf
- composed of xylem and phloem
- xylem to transport water
- phloem to transport sucrose and amino acids
what adaptations make the leaf structure good for photosynthesis
- large surface area for diffusion of co2 and absorption of light
- network of veins for water transportation to the cells
- cells contain chlorophyll so light energy can be absorbed for energy for photosynthesis
- thin leave facilitates diffusion of co2 through the stomata
- air spaces increase SA for diffusion of co2
why do plants need mineral ions
for growth
why do plants need magnesium ions
for the production of chlorophyll
why do plants need nitrate ions
for the production of amino acids
what do plants store their glucose as
starch
what should a healthy diet include
- carbohydrates
- proteins
- lipids
- vitamins
- minerals
- water
- dietary fibre
sources and functions of carbohydrates
bread and pasta
it is quick energy