bio ch.8 lab

Plants use carbon dioxide and the energy from the sun during ____________ to produce glucose.

photosynthesis

Photosynthesis is a combination of

multiple chemical reactions

A reactant of photosynthesis whose general levels can be measured is

carbon dioxide

_________ is a measure of the amount of hydrogen ions in a solution.

pH

The greater the amount of hydrogen ions, the ___________ the solution.

more acidic

As hydrogen ions are removed from a solution it becomes

more basic

Carbon dioxide combines with water to form

carbonic acid

Therefore, the more carbon dioxide in a solution, the __________ it will be.

more acidic

is a pH indicator that turns yellow in an acidic environment & pinkish-red in basic solutions

phenol red

What is happening to the level of carbon dioxide in the experimental test tube with the Elodea leaf as indicated by the red color in the tube?

The level of carbon dioxide is decreasing.

What is happening to the level of carbon dioxide in the negative control test tube without the Elodea leaf as indicated by the yellow color in the tube?

The level of carbon dioxide is unchanged.

Why are carbon dioxide levels changing in the tube with Elodea?

Carbon dioxide levels are dropping because carbon dioxide is a reactant in photosynthesis.

A product of photosynthesis that can be measured is

oxygen

________ is crucial to providing the energy needed for photosynthesis.

light

One method to observe the progress of photosynthesis is to monitor the

production of one of its products, oxygen.

_________________ solution provides carbon dioxide and water

Sodium bicarbonate (NaHCO)

A __________ allows the measurement of volume change due to displacement of a liquid. The liquid may be displaced by addition or removal of a substance, such as oxygen.

volumeter

Carbon dioxide molecules react with water molecules using light energy to produce

oxygen, water, and a glucose molecule

Why do you need to add carbon dioxide with the 3% sodium bicarbonate (NaHCO,) solution?

Carbon dioxide can be used by plants to make glucose during photosynthesis.

Why cover one test tube in aluminum foil?

The foil blocks light.

What are the reactants for photosynthesis?

carbon dioxide & water

Plants exposed to _________ will show a greater rate of photosynthesis compared to those exposed to green light.

blue light

Why does blue light lead to a greater rate of photosynthesis compared to green light?

Plants absorb certain wavelengths of light better than others for use in photosynthesis. Green light is reflected back and its energy is not fully available for use in photosynthesis.

Why is a 3% sodium bicarbonate (NaHCO,) solution added to each test tube?

- it is a source of water

- It is a source of carbon dioxide

Why is the volume level for the Elodea exposed to white light increasing?

The plant is undergoing photosynthesis and producing oxygen.

Why is the volume level for the Elodea covered with foil decreasing?

The plant is undergoing cellular respiration and is consuming oxygen.

What do the "White light" (solid red) and "Darkness" (striped orange) bars represent?

The solid red bar shows how oxygen volume increases due to photosynthesis, and the striped orange bar shows how oxygen volume decreases due to aerobic cellular respiration and a lack of photosynthesis.

Based on your results, what can you conclude from the "determining white light" experiment?

Plants exposed to white light will undergo photosynthesis and produce oxygen.

The pigments that are more soluble will migrate ______ than those that are less soluble.

farther

Chlorophyll a is

blue-green

Chlorophyll b is

yellow-green

Carotenes are

orange

Xanthophylls are

yellow

What is the purpose of the chromatography solvent?

The pigments dissolve in the chromatography solvent, which allows them to be separated.

What is the purpose of using extract from chloroplasts?

Chloroplasts contain the photosynthetic pigments.

Why does chlorophyll b appear yellow-green?

It reflects light in those wavelengths and absorbs violet and red.

Why did the different photosynthetic pigments migrate to different points on the chromatography paper?

The pigments differ in their solubility in the solvent and affinity for the paper