bio unit 2: chapter 8

Visible light has a wavelength range of

400-700 nanometers

How many revolutions of the Calvin cycle are required to produce the sugar glucose?

6

What products of light reactions of photosynthesis are used in the Calvin cycle?

ATP and NADPH

Under what circumstances would increasing light intensity not result in an increase in the rate of photosynthesis?

At any given time, the rate of photosynthesis is limited by the factor which is in the shortest supply. Therefore, if a factor other than light is limited, increasing the light intensity would not result in an increase in the rate of photosynthesis.

The ______ plants utilize a specialized carbon fixation enzyme and a unique cell structure to reduce the problems of photorespiration

C4

_______ adapted plants such as cacti, pineapples, etc. show a pattern of stomatal opening and closing that is the reverse of C3 plants

CAM

Jean Baptista van Helmont performed an experiment in which he planted a small willow tree in a pot of soil, after weighing both the plant and the soil. He watered the plant regularly. At the conclusion of the experiment five years later, the weight of the tree increased by 74.4 kg, while weight of the soil decreased by 57 kg. The primary source of the increased weight (mass) of the plant is from

CO2 in the air

The cyclic carbon fixation reactions are also known as the

Calvin cycle

Which of the following is not part of the light-dependent reactions

Calvin cycle

Most plants incorporate carbon dioxide into sugars by means of a cycle of reactions called the

Calvin cycle.

If chlorophyll a is blocked from absorbing, what will happen to chlorophyll b since it is an accessory pigment?

Chlorophyll b will still absorb near the green wavelengths of light, but photosynthesis will be greatly reduced.

Describe the conflict between a plant's need to undergo photosynthesis and its need to conserve water when it is in short supply. Briefly state how plants overcome this problem.

For photosynthesis to occur, plants need to take in CO2 and release O2. Plants accomplish this task by opening and closing the stomata on their leaves. Each time the stomata are open, however, plants also lose water vapor. If water is in short supply, this loss can decrease the rate of photosynthesis. To overcome this problem, plants undergo photorespiration.

Which of the following statements best describes the relative concentrations of G3P and RuBP in a chloroplast as a result of a transition from daytime (light) to nighttime (dark)?

G3P would increase and RuBP would decrease

Your research project involves a mutational analysis of the light harvesting complex Lhca1. Your labmate asks if you are working on a cytochrome found in the outer membrane of the chloroplast. You explain that

I am working on a protein found in the antenna complex and it is located in the thylakoid membrane

Which of the following scientists is not associated with studies on photosynthesis?

Krebs

Photosystem II differs from photosystem I in that _____________ is not made directly from the process

NADPH

The Calvin cycle is driven by ATP and _____ produced in the light reactions

NADPH

Photosystem II absorbs protons that are slightly more energetic than photosystem I, but similarly pass this energy to a pigment called

P680

In the photosystem I photocenter, light energy captured by pigment molecules is passed on to a special molecule called

P700.

__________ is the process by which certain organisms capture energy from sunlight and use it to build energy-rich food molecules.

Photosynthesis

In the dark reactions of photosynthesis, CO2 is added to a five-carbon sugar-phosphate known as

RuBP

Which of the following statements supports the fact that chlorophyll a is not the only pigment involved in photosynthesis?

The rate of photosynthesis is high at wavelengths when the absorption by chlorophyll a is low.

In the plants that utilize the CAM pathway, what happens to the stomata?

The stomata open in the evening but close in the morning.

Carotenoids are important to many plants because these pigments are able to

absorb wavelengths of light that neither chlorophyll a nor b can absorb

Each pigment molecule has a characteristic ________ spectrum.

absorption

Which of the following would not be considered to be a function of the antennae complex in photosynthesis?

acts as reaction center

Engelmann (1883) determined the wavelengths of light that plants could use most effectively. He used a green algae and __________ to obtain his results.

aerobic bacteria

Chlorophyll b absorbs in green wavelengths of light that chlorophyll a cannot absorb. In this respect, chlorophyll b acts as

an accessory pigment

What did the radioactive molecules represent

carbon compounds produced in the Calvin cycle

Carbon atoms of CO2 are incorporated into organic molecules in a series of dark reactions called

carbon fixation.

Fall leaf color on deciduous trees is a result of

cessation of chlorophyll production, which allows the accessory pigments to be revealed.

The general process whereby protons accumulate on one side of a membrane and can flow back across the membrane through ATP synthase resulting in ATP production is called _________________

chemiosmosis

In eukaryotes, photosynthesis takes place inside the _________

chloroplasts

The dark reactions of photosynthesis are those that

convert CO2 into reduced molecules (sugars)

Even though the Calvin cycle reactions require the products of the light reactions, its reactions can occur in the ________

dark

The wavelengths absorbed by a particular pigment depend on the available ______ levels to which the light-excited electrons can be absorbed

energy

Which of the following experimental modifications would help to determine the sequence of reactions and the reaction intermediates in the Calvin cycle?

exposing the cells to 14 CO2 for various time intervals

Your class project involves a presentation of the photoelectric effect. Which of the following materials would be the most helpful for a clear demonstration?

glow in the dark stickers and a UV light

Apparent color of chlorophylls.

green

Visible light not strongly absorbed by chlorophyls

green

The loss of carbon fixing activity of the enzyme RuBP carboxylase is directly proportional to

high temperatures and high light intensities

A scientist is hoping to synthesize a new herbicide that will kill certain weeds. She has found that one weed species in particular has thylakoids that have rather large pores. The herbicide will open the pores of these thylakoids, causing them to leak

hlorophyll

Engelmann (1883) discovered that the wavelengths of light that chlorophyll most strongly absorbed were

in the red-violet wavelengths of the visible light spectrum

The photosynthetic electron transport causes the accumulation of protons in which part of the chloroplast

internal thylakoid space

In the _____ reactions of photosynthesis, electron carrier molecules are reduced and ATP is synthesized.

light

One of the disadvantages of the C4 pathway is that it requires

more ATP

During electron transport, the thylakoid space becomes

more acidic than the stroma

If you exposed a C4 plant to 14CO2 in the light, which of the following would be the first organic molecule labeled with 14C?

oxaloacetate

The Calvin cycle requires all of the following except

oxygen

In dark reactions, when CO2 is added to a molecule of RUBP the product is

phosphoglycerate

Light consists of units of energy called

photons

CO2 is released without the production of ATP or NADPH. This process is called

photorespiration

merson and colleagues discovered the enhancement effect while studying photosynthesis in green algae. The algae were illuminated with light of either 680 nm or 700 nm, and the rate of photosynthesis was measured. The researchers found that the rate of photosynthesis when the lights were applied simultaneously was greater than the sum of the rates when the lights were applied individually. These results provided evidence that

photosynthesis is carried out by two photosystems that act in series.

Plants and algae use a two-stage _________ in the light dependent reactions

photosystem

Clusters of chlorophyll and accessory pigments are called _________

photosystems

You are working to isolate pigments from a cyanobacteria species recovered from the ocean floor. Which of the following would you most likely expect to find?

phycobiloproteins

Molecules that absorb light are called

pigments

Embedded in the thylakoid membrane and protruding as knobs from the outer surface into the stroma, there are

proton channels that synthesize ATP

Visible light with longest wavelength and lowest-energy photons; one of the regions where chlorophylls absorb

red

The connection between carrots and vision is that the β-carotene of carrots can produce two molecules of vitamin A and oxidation of vitamin A produces a pigment used in vertebrate vision. This pigment's name is

retinal

In which part of the chloroplasts are the Calvin cycle enzymes located?

stroma

A method devised by succulent desert plants to reduce the problem of photorespiration is

the CAM metabolism

Carbon fixation occurs during the dark reactions, or _____________, in photosynthesis

the Calvin cycle

Which of the following is common to both cellular respiration and the light reactions of photosynthesis?

the chemiosmotic formation of ATP

The plant hormone abscisic acid (ABA) is involved in the regulation of photorespiration. Based on this information, ABA likely plays a role in

the opening and closing of stomata.

The photosystem channels the excitation energy gathered by absorption of light by any one of the pigment molecules to a specific "reaction center chlorophyll," which in turn passes the energy to

the primary electron acceptor

Flattened sacs of internal membranes associated with photosynthesis are called

thylakoids

Sunburn is caused by which component of sunlight?

ultra violet rays

High energy component of the electromagnetic spectrum; associated with sunburn.

ultraviolet

Shortest wavelength and highest-energy photons within the visible spectrum; one of the regions where chlorophylls absorb

violet-blue

C. B. van Niel used sulfur bacteria in his research on photosynthesis. His equation involved carbon dioxide and hydrogen sulfide. The bacteria produce sulfur. In green plants which molecule is split to form the oxygen?

water

Most of the atmospheric oxygen occurs as a result of photosynthesis. From which of the following molecules is the oxygen derived?

water

In green plant photosynthesis, the electron donor for the light dependent reaction is

water.