Photosynthesis Test Part 1

Which of the following is a true statement about chlorophyll? 1. It absorbs mostly green light. 2. It is responsible for the red and orange colors of leaves in the Fall. 3. It absorbs red and blue light the best. 4. It is usefurl for photosynthesis, but not absolutely necessary.

3. It absorbs red and blue light the best.

What do the initials ADP and ATP stand for? What is the role of these molecules inside a cell?

ADP = adenosine diphosphate ATP = adenosine triphosphate ATP is a source of immediate energy for all cellular processes requiring energy.

How does ADP become ATP? Where does this energy come from?

ADP become ATP when the third or terminal phosphate is bonded to the ADP molecule. This addition of the third phosphate requires energy, and energy is then stored in the bond that is formed. The energy required to produce ATP comes from the oxidation of glucose molecules during cellular respiration.

How many phosphate groups are in ADP? How many phosphate groups are in ATP? What is the significance of the third phosphate?

ADP has two phosphate groups. ATP has three phosphate groups. The addition of the third or terminal phosphate to ADP forms ATP. As this third phosphate is bonded to ADP, energy is consumed, and therefore stored, in the bond. The third phosphate is removed whenever energy is needed for some cellular process. The removal of the third phosphate releases energy.

Organisms that can make their own food.

Autotrophs

What is the difference in the way autotrophs and heterotrophs obtain energy? Give examples of autotrohs and heterotrophs.

Autotrophs are organisms that are capable of making their own food. They use the light energy from the sun to produce food in the form of glucose or sugar molecules. (NOTE: I wrote this assignment for my standard Bio I class and did not teach chemosynthesis to them. There are autotrophs that produce their food using the energy released from inorganic chemical reactions rather than the energy from the sun.) Heterotrophs are not capable of producing their own food. Heterotrophs must consume food. Heterotrophs eat plants or eat other animals that have eaten plants. Autotrophs include: Green plants, some bacteria, some protists. Heterotrophs include all animals and all fungi.

What is the equation for photosynthesis? How does the plant obtain each of the reactants?

CO2 + H2O + light energy C6H12O6 + O2 Carbon dioxide is abundant in the atmosphere. The plant takes it in through the stomata in the leaves. Water in the ground is absorbed by the roots of the plant. The water then travels up the plant to the leaves via the xylem.

How does chlorophyll make a plant appear to be green?

Chlorophyll absorbs all wavelengths of the visible spectrum except green light. Green wavelengths are reflected by chlorophyll, so chlorophyll appears to be green to our eye.

What is the name of the waxy layer found on the upper and lower surface of a leaf?

Cuticle

TorF: ATP is very energy poor and ADP is very energy rich.

False

TorF: All parts of the plant are capable of carrying out photosynthesis.

False

TorF: Carbon dioxide is produced during photosynthesis.

False

TorF: Heterotrophs depend on autotrophs, but autotrophs are not dependent on heterotrophs.

False

TorF: The primary photosynthetic cells of a leaf are the spongy cells.

False

Life on earth is dependent on photosynthesis for what two things?

Food and oxygen

Why do autotrophs depend on heterotrophs?

For carbon dioxide

Why is this waxy layer (found on the upper and lower surface of a leaf/cuticle) necessary?

Helps to prevent water loss

Organisms that cannot make their own food.

Heterotrophs

During photosynthesis, the _________ from the sun is used to produce molecules of __________.

Light energy. Glucose.

What is the name of the middle portion of the leaf?

Mesophyll

Which one of the following is not required for photosynthesis?

Oxygen

What is the name of the cells in the leaf that are the primary photosynthetic layer of the leaf?

Palisade cells

This carries food out of the leaf to all other parts of the plant.

Phloem

Any substance that absorbs light.

Pigment

Water is required for photosynthesis. How does the plant acquire this?

Roots

Carbon dioxide is required for photosynthesis. How does the plant acquire this?

Stomata

Pores on the underside of the leaf that let carbon dioxide into the leaf.

Stomata

Describe the three parts of ADP/ATP molecule.

The ADP / ATP molecule consists of the nitrogen base adenine, the five carbon sugar ribose, and either 2 or 3 phosphate groups.

Why might the stomata be called "necessary evils"?

The stomata must open to let in the carbon dioxide needed for photosynthesis. While open, water vapor is lost from the leaf. If too much water escapes the leaf, the plant will wilt and possibly die. Often the stomata must close to conserve water, but while closed the plant cannot obtain the carbon dioxide it needs for photosynthesis. It is a balancing act.

What plant structures control the passage of H2O out of the plant and CO2 into the plant?

The stomata of the leaf.

What is the ultimate source of energy for all living things on earth?

The sun.

List four cellular activities that would require the energy of ATP.

There are many possible answers to this question. Some possibilities might include: muscle contraction, active transport, photosynthesis, protein synthesis, cell division.

TorF: Photosynthesis is the process of trapping the sun's energy in order to make molecules of glucose.

True

What happens to make ATP become ADP? Why is this important for the life of the cell?

When the third or terminal phosphate is removed from ATP, the resulting molecule is ADP. This is important to the cell because energy is released and is available for cell work.

This carries water to the leaves from the roots.

Xylem