Plant nutrition and transport Flashcards
What does photosynthesis produce?
Glucose using sunlight
Where does photosynthesis occur?
The leaves of all green plants
Where does photosynthesis occur?
In the chloroplasts
What does chlorophyll in the chloroplast do?
Absorbs sunlight, and uses this energy to convert carbon dioxide and water into glucose and oxygen
Word equation for photosynthesis>
Carbon Dioxide + Water = glucose + oxygen
Symbol equation for photosynthesis?
6CO2+ 6H2O = C6H12O6 + 6O2
Structure of a leaf?
P 19
How are leafs adapted for efficient photosynthesis?
Leaves are broad so large surface to absorb light
Most chloroplast found in palisade layer, so near most light
Upper epidermis is transparent
Vascular bundles take away the glucose produced by photosynthesis
Waxy cuticle reduces water loss by evaporation
Stomata let CO2 diffuse directly into leaf
Limiting factors of photosynthesis?
Not enough light
Not enough CO2
Correct temperature, higher means more photosynthesis, but too high denatures enzymes reducing photosynthesis
How to test a leaf for starch?
Boil leaf in water to prevent further chemical reactions
Put leaf in boiling tube with Ethanol, heat in water bath, gets rid of any chlorophyll, making the leaf white
Rinse in water add iodine solution if present will turn black/blue
What’s the starch test used for?
To see if a plant can photosynthesis
How to show chlorophyll is needed for photosynthesis?
Do the starch test and you’ll notice only the green parts are positive for starch
How to show CO2 is needed for photosynthesis?
Leave a leaf with soda lime to remove all CO2, and see t doesn’t test positive for starch
How to show light is needed for photosynthesis?
Place plant in dark environment for a week, won’t test positive in starch test
What aspect can you use to measure photosynthesis?
Oxygen production
How to measure oxygen production in a plant?
Use Canadian pond weed in water, a measure the amount of oxygen produced. Repeat and change the factors
Why do plants require mineral ions?
Need elements to produce certain compounds, get these from mineral ions in the soil, if they don’t they will show deficiency symptoms.
Why do plants require Nitrates?
Making amino acids and proteins, for cell growth
What are the deficiency symptoms of no Nitrates>
Stunted growth, and yellow older leaves
Why do plants require Phosphates?
Making DNA and cell membranes, for respiration and growth
What are the deficiency symptoms of no Phosphates?
Poor root growth, and purple older leaves
Why do plants require potassium?
To help enzymes required for photosynthesis and respiration
What are the deficiency symptoms of no Potassium?
Poor flower and fruit growth, discoloured leaves
Why do plants require magnesium?
Making chlorophyll
What are the deficiency symptoms of no Magnesium?
Yellow leaves
Why do multicellular organisms require transport systems?
They’re too big for substances to diffuse directly into cells would take too long.
What do xylem tubes do?
Transport water and mineral salts from the roots to the leaves through the transpiration stream
What do Phloem tubes do?
Transport Sucrose and amino acids from the leaves to the other parts of the plant, this is called translocation
What do root cells take in by osmosis?
Water
How are they adapted for efficient exchange?
Long hairs into soil
Lots of hairs
Big surface area
Why is the water taken in by osmosis?
The concentration of water is higher outside the root hairs
What do root cells take in by active transport?
Mineral ions
What’s transpiration?
Loss of water from a plant via evaporation and diffusion in the leaves, so more water is drawn up by the xylem vessels and roots creating a transpiration stream
How does light intensity effect the transpiration rate?
Higher the light, the more transpiration
Stomata close as it gets dark, photosynthesis can’t happen in the dark so the stomata don’t need to be open to let CO2 in, stopping the water from leaving the plant
How does temperature effect transpiration?
The warmer it is, the faster transpiration happens
The water particles have more energy so they evaporate more
How does wind speed effect transpiration?
The higher the wind speed, the faster transpiration happens
Sweeps away water molecules outside the leaf, maintaining a low concentration of water outside the leaf
How does humidity effect the transpiration rate?
The more humid, the slower transpiration happens
Creates a high concentration if water outside the leaf, so diffusion happens slower
How to use a potometer to measure transpiration?
Cut shoot underwater with a slant to increase surface area
Assemble photometer underwater and put in shoot
Remove from water, but keep the capillary tube in water
Make sure it’s airtight
Dry the leaves
Measure how far the bubble moves per time
What can you do to test the environmental effects on transpiration?
Change light intensity, temperature, wind speed, humidity
