Photosynthesis

For IB Biology

Be able to state the basic scientific explanation of photosynthesis in simple terms (one sentence).

choose the correct answer:

A. Photosynthesis is how plants make food energy in the form of glucose.

B. Photosynthesis plants use water and carbon dioxide to make simple sugar.

C. Photosynthesis is how light energy is converted into chemical energy.

D. Photosynthesis is how light energy makes sugar in a chloroplast.

Sunlight• Light from the sun is composed of a range of

wavelengths.

A beam of white light is passed through a cut glass prism.Each different wavelength is bent at a different angle do to the wave frequency

and therefore– energy.

Different substances absorb different wavelengths of light. Molecules that absorb wavelengths of light are called “pigments” .

In living things pigments are substances that produces a characteristic

color in tissue.

Hemoglobin is a pigment in blood.

Chlorophyll is the MAIN photosynthetic pigment.

Spectrophotometer

Write these down: 380 to 800 by 20s

WAVELENGTHS OF LIGHT• 380• 400• 420• 440• 460• 480• 500• 520• 540• 560• 580• 600• 620• 640• 660• 680• 700• 720• 740• 760• 780• 800

% Absorbance________________________________________________________________________________

Graph the absorbance of chlorophyll

Homework

• Bring three images of a chloroplast taken from an electron microscope. - prefer a transmission electron microscope (TEM)

• Due- next class

• Extra credit: using a blender, grind up the leaves a differently colored plant .– Add enough water to the blender to cover the leaves packed in the

bottom. You will need at least a handful of leaves. Strain, and bring the liquid to school. Keep in a refrigerator until you come to school.

– Make sure you bring a sample of the leaf so we know what it looked like before. (unblended)