Biology Ch 8

Anoxygenic bacteria have how many photosystems?

One

The production of one molecule of ____ from water during photosynthesis requires several thousand chlorophyll molecules.

Oxygen

Which photosystem's main function is to generate high-energy electrons for the synthesis of ATP?

Photosystem II

In all photosynthetic organisms studied to date, except one class of photosynthetic bacteria, light is captured by clusters of chlorophyll and accessory pigment molecules, which together are called

Photosystems

The C4 pathway has a cost to plants, because the conversion of ____ to PEP requires the expenditure of ATP.

Pyruvate

When light strikes a pigment, some wavelengths are absorbed and some are reflected. For instance, a leaf that appears green to the eye ___ green wavelengths of light.

Reflects

What is ultimately the main source of energy for almost all living cells on Earth?

The sun

The production of one molecule of O2 during photosynthesis requires how many chlorophyll molecules?

Thousands NOTE: In fact, as many as 2500 molecules of chlorophyll may be needed, most of them located in the light-harvesting complexes of photosystems.

How many different types of photosystems are found in chloroplasts?

Two

How many types of photosystems are found in chloroplasts?

Two

What is the net gain of the Calvin cycle?

Two molecules of G3P

A photon of light has properties of both

a particle and a wave

The ATP needed in the Calvin cycle comes from

both cyclic and noncyclic photophosphorylation

A C3 plant

can only fix carbon using the Calvin cycle

van Niel introduced the term ____ to denote the process of converting CO2 into organic matter using the electrons and protons resulting from the splitting of water.

carbon fixation

The ATP synthases of chloroplasts and mitochondria are

evolutionary related

The enzyme rubisco has more than one activity. Because of this, most plants also perform _____, which consumes oxygen and liberates carbon dioxide. This process can lower the net benefit from photosynthesis.

photorespiration

Almost all photosynthetic organisms capture light using

photosystems

Recent studies with the atomic force microscope have shown that PSI and the ATP synthase are not randomly distributed in thylakoid membranes, rather, they seem concentrated

primarily in the connections between grana (the stroma lamellae).

The internal membrane of the chloroplast is also known as the

thylakoid membrane

Jan Baptista ______ performed an experiment for which he grew a willow tree in a pot for several years, during which time he kept an exact record of changes in the weight of the soil.

van Helmont

Which of the following statements best describes the properties of light?

Light has properties of both a particle and a wave.

The energy used by most living cells comes ultimately from the ___ and is captured through the process of ____

Sun ; Photosynthesis

The inner (internal) membrane of the chloroplast is also called ____ the membrane.

Thylakoid

The light-____ reactions of photosynthesis occur on membranes.

dependent

A leaf that appears to be green to the human eye contains pigment molecules that are

reflecting green light

According to the diagram, which of the following accelerate photosynthesis when light intensity is high?

- Increase in CO2 - Increase in temperature

The following diagram shows the change in the rate of photosynthesis as a function of the intensity of light under varying conditions. Which of the following statements (choose all that apply) can be concluded based on the following graph?

- The rate of photosynthesis is limited by temperature at high light intensities. - The rate of photosynthesis is limited by the concentration of CO2 at high light intensities. - The rate of photosynthesis is limited by light at low light intensities

Photophosphorylation produces _____, which stores chemical energy that can be used for the Calvin cycle. Carbon fixation also requires reducing power, which is provided by _____ produced by photosystem I.

ATP ; NADPH

Compared to the C3 pathway, the C4 pathway has an additional cost to a plant, because

ATP is required to convert pyruvate to PEP NOTE: PEP is formed when pyruvate bonds are broken.

The electron transport chain directly associated with photosystem II is used to generate __, while the electron transport chain directly associated with photosystem I is used to generate __.

ATP; NADPH

Which of the following organisms have only one photosystem?

Anoxygenic bacteria

Why is the Calvin cycle also known as C3 photosynthesis?

Because the first molecule in the cycle has 3 carbon atoms.

Plants that only fix carbon using the Calvin cycle are also known as ___ plants.

C3

The Calvin cycle is also known as ____ photosynthesis because the first intermediate of the cycle contains three carbon atoms.

C3

____ plants avoid water loss by closing their stomata during the day and opening them at night.

CAM

How do CAM plants avoid water loss?

CAM plants close their stomata during the day and open them at night

According to the generalized equation for photosynthesis proposed by van Niel, CO2 + 2H2A + light energy yields which of the following?

CH2O + H2O + 2A

What molecule is released during photorespiration?

Carbon dioxide NOTE: Photorespiration uses O2 and liberates CO2. Essentially undoing carbon fixation

The two most important classes of pigments in chloroplasts are chlorophylls and _____

Carotenoids

Which are the two most important kinds of pigments in chloroplasts?

Chlorophylls and carotenoids

True or false: The mechanism of ATP synthesis in the ATP synthase of chloroplasts is fundamentally different from the one used in the ATP synthase of mitochondria.

False

The thick arrow points to which part of the chloroplast?

Grana

In van Niel's generalized equation of photosynthesis, which of the following is the donor of electrons?

H2A

Carbon fixation involves using the protons and electrons generated by the splitting of what molecule to convert CO2 into organic matter?

H2O

Which of the following describes van Helmont's experiment?

He grew a willow in a pot keeping an exact record of the weight of the soil and the tree over several years.

According to recent studies, where are PSII and the b6-f complexes located?

In the grana and in borders between the grana and the stroma lamellae

Where do the light-dependent reactions of photosynthesis occur in the chloroplast?

In the thylakoid membrane.

The red arrow points to which part of the chloroplast?

Inner membrane