Kingdom PlantaeKingdom Plantae

NutritionNutrition

Photosynthesis-

The process of converting solar energy to chemical energy

Used by green plants, algae, euglena, and the blue-green bacteria

6 CO2 + 6 H2O -------------> C6H12O6 + 6 O2

Carbon Water Glucose Oxygen dioxide

How we perceive color

Sunlight is a mixture of all visible wavelengths Objects appear a certain color because they are

reflecting that wavelength So when we look at green plants, red and blue

light is absorbed (used for photosynthesis) and green light is reflected

The visible spectrum

Light travels in particles that form waves

The shorter the wavelength the greater the available energy

Violet=the greatest energy Red=the lowest energy

Pigments-substances that absorb light

Photosynthetic pigments 1) chlorophyll a-primary photosynthetic pigment

2) chlorophyll b

3) carotenes-reflect orange light

4) xanthophylls-reflect yellow light

Chlorophyll a hides the other pigments

It is the first to break down in the fall when sunlight decreases and temperatures cool

This is why we see other colors in the fall

Chloroplasts-cell organelle containing photosynthetic membranes and pigments Thylakoids-”green disks”,

the photosynthetic membranes inside

Grana-stacks of thylakoids

Stroma-regions around the grana

Stroma

Thylakoids

Photosynthesis-

The process by which organic compounds (glucose) are synthesized in the presence of carbon dioxide and light

Factors affecting photosynthesis

1) light intensity-as intensity increases, rate of photosynthesis increases (to a certain point)

2) water-a deficiency will slow or stop photosynthesis

3) minerals, carbon dioxide, nutrients-a deficiency will slow or stop photosynthesis

4) temperature-this influences enzyme activity

Heterotrophic plants

Mistletoe-a parasitic plant It photosynthesizes but also

takes sap from the vascular tissue of host plants such as oaks

Heterotrophic plants con’t

Indian pipes-does not photosynthesize Lives symbiotically with a

fungus

Heterotrophic plants con’t

Pitcher plants-photosynthetic but supplements missing nutrients in its environment with nitrogen from captured insects Venus flytrap does this too!

Venus Flytrap

Plant Regulation

Remember the factors that affect photosynthesis? Plants need to regulate carbon dioxide intake and water

loss Leaves have pores called stomata

that let carbon dioxide in

and oxygen out

Stomata

If stomata are open, what is lost along with oxygen?

Water!!!!

So plants close stomata during times of high water loss (like hot, sunny days)

Guard cells

The cells surrounding the pores or stomata of a leaf are called guard cells.

In the photo, the dark center is the stomate and the cells surrounding it are the guard cells.