BIOL 1408 - Photosynthesis lab review
In order for starch to be stored on the leaf,
the leaf must be exposed to light
The shorter the wavelength of the light
the stronger the energy with which it travels. Thus, the blue-violet end of the spectrum is more energetic than the red end.
The light reactions occur at the
thylakoid membrane
We see objects in color because
when light hits the object, most of the wavelengths are absorbed, but some are reflected. It is the reflected wavelengths we see as the color of the object.
Which pigment has the greatest affinity for the paper (is most attracted to the paper)?
Chlorophyll b
The organelle that carry out photosynthesis
Chloroplasts
What wavelength and colors of light is not absorbed well (reflected/transmitted) by the spinach extract (chlorophylls mainly)?
Green.
What wavelengths and colors of light are not absorbed well (reflected/transmitted) by the carrot extract (carotenoids)?
Yellow, red, orange.
A spectroscope is
a device that shows the wavelengths of light that enters it.
a: Thylakoid b: Stroma c: Outer membrane
a. site for light reactions, electron transport chain and ATP-synthesizing enzymes. b. Site for Calvin cycle c. Surrounds the organelle
In the fall, leaves turn red, orange, yellow, and eventually brown. Where did the green color go?
It disintegrated when the water, nutrients, and sugar were cut off.
Photosynthesis consists of
Two linked processes called the light reactions and the Calvin cycle (dark reactions).
Visible light consists of electromagnetic energy of different wavelengths ranging
from about 380 to 750 nm.
Paper chromatography
is used to separate substances from one another based on their characteristics.
Calvin cycle (dark reactions)
is where the sugar is formed. Carbon dioxide from the air is taken into the chloroplast and is fixed into an organic molecule. The chloroplast uses products from the light reactions (ATP + NADPH + hydrogen ions) to convert CO2 into a carbohydrate.
Pigments are
lipids in nature so a lipid solvent will be needed in a pigment chromatography.
The light that comes from the sun looks white or colorless to us, but in fact is
made of all wavelengths (colors) or light.
Heterotrophs
obtain their energy by consuming other life forms. Humans are one example of heterotrophs and break down the complex molecules they consume to obtain energy.
The most common from of carbohydrate stored by plants is:
starch, a polymer of glucose.
The Calvin cycle (dark reactions) occurs in the
stroma
Which pigment has the greatest affinity for the solvent (is most soluble in the solvent and travels right along with the solvent)?
Carotene
What pigment do you think is present in the highest concentration during the spring season when many leaves of deciduous plants are green?
Chlorophyll
Regions of the chloroplast are
1-outer membrane 2-inner membrane 3-intermembrane space 4-stroma 5-thylakoid disk granum - one stack grana - multiple stacks
Balanced equation for photosynthesis
6 CO2 (carbon dioxide) + 12 H2O (water) + light energy -------> C6H12O6 (glucose/carbohydrate) + 6 O2 (oxygen) + 6 H2O (water).
The formula of photosynthesis indicates a carbohydrate as an end product.
6 CO2 (carbon dioxide) + 12 H2O (water) + light energy ------> C6H12O6 (carbohydrate/glucose) + 6 O2 (oxygen) + 6 H2O (water)
Why are plants green in color?
The leaf contains pigments, which absorb the wavelengths of light required to split water. Leaves contain different levels of these pigments depending on the time of year. The main pigments found in the chloroplasts are chlorophylls a and b (which reflect green) and carotenoids (which reflect red-orange-yellow).
The stages of photosynthesis are
The light reactions and the Calvin cycle (also known as the dark reactions because they are light-independent).
Plants are called _________________ because they use sunlight energy directly and combine inorganic compounds to form organic molecules.
autotrophs
spectrophotometer
can be used to measure absorption and transmittance of light through solutions.
The solutions that will be tested in this lab are solutions of
carrot pigment extract, and spinach leaf pigment extract,
Photosynthesis occurs in the
chloroplasts
The finished product in paper chromatography is called:
chromatogram
Light reactions
occurs when light splits water into oxygen and hydrogen. The hydrogen is then further split into a hydrogen ion and a free electron. The reaction is driven forward by the presence of a coenzyme, NADP+, which accepts the electron and the hydrogen ion to become NADPH, preventing the reformation of water. the light reactions also form ATP by photophosphorylation.
Plants utilize the sun's energy in a process called:
photosynthesis
leaf pigments are removed by
placing it in boiling 95% ethanol. (Ethanol cannot be boiled directly on the hotplate. A beaker containing ethanol is placed into a larger beaker of boiling water.)
