Topic E - Photosynthesis Flashcards
Equation for photosynthesis
Carbon dioxide + water ——-> Glucose + oxygen
Chemical equation of glucose
Glucose = C6 H12 O6
What is photosynthesis
Process which green plants use sunlight energy to make food
What does Photo + synthesis mean
Light + Make
What does photosynthesis use
Inorganic substances to make Organic substances
What are green plants called
Producers
What green pigment do plants contain
Chlorophyll
Where is chlorophyll found
In chloroplasts
What does chlorophyll do
Absorbs light energy
How does water enter plants
Through the roots
How does carbon dioxide enter plants
Through stomata in the leaves
Large surface area
To absorb more light
Name of veins
Phloem + Xylem
Function of stomata
Open and close to control water loss
Gas exchange
Function of spongy mesophyll cells
Air spaces between them so essential carbon dioxide and waste oxygen can get in and out- DIFFUSION
What travels in the xylem and in what direction does it go
Water from root hair cells
Travels up the stem to leaves
What travels in the phloem and where is it transported to
Sugars produced in the leaves
Transported to all parts of plant
Function of cuticle
covered in wax
waterproof
stops water escaping through epidermis
Why are palisade cells long and closely-packed ( relate to photosynthesis
Long- contain lots of chlorophyll
Closely-packed - more they are faster will carry out photosynthesis
Why are the epidermis and cuticle transparent
To allow light to reach the palisade cells
Which types of cells in a leaf contain chloroplasts
Palisade layer
What are the 6 uses of sugar( glucose) in a leaf
- Energy ( used instantly)
- Starch (insoluble)
- Cellulose cell wall
- Lipids( in seeds)
- Sucrose (nectar
- Amino acids (growth)
What are 3 factors that effect the rate of photosynthesis
Light intensity
Amount of Carbon dioxide
Temperature
Explain rate of photosynthesis and light intensity
Brighter the light the faster the rate of photosynthesis
Explain rate of photosynthesis and carbon dioxide
constant level in air = 0.03%
if decreases below 0.03% rate is slower
Explain rate of photosynthesis and temperature
photosynthesis controlled by enzyme
low temp.= slow rate reaction
optimum temp.= 40’c (plants at 22-23’c)
high temp= denatures enzymes
what happens if one of the 3 factors ( rate ) is short in supply
will limit the rate of photosynthesis no matter how much of the others is available
