Chapter 10 Homework

When oxygen is released as a result of photosynthesis, it is a direct by-product of _____. When oxygen is released as a result of photosynthesis, it is a direct by-product of _____.

splitting water molecules

Calvin cycle outputs

ADP NADP+ G3P

Calvin cycle inputs

ATP NADPH CO2

The electrons derived from this oxidation reaction in the Calvin cycle are used to reduce ________ to _______ .

CO2 G3P

Not an input or output of light reactions

Glucose CO2 G3P

In the light reactions, light energy is used to oxidize _________ to __________.

H20 O2

Why is it not entirely accurate to adopt the common phrase "light-independent reactions" when referring to the Calvin cycle?

Although its reactions are not triggered directly by light, they depend on the products of light-capturing reactions.

What event accompanies energy absorption by chlorophyll (or other pigment molecules of the antenna complex)?

An electron is excited.

The proteins of the electron transport chain active in the light-dependent reactions _____.

Are membrane proteins present in the thylakoid

Chlorophylls absorb most light in which colors of the visible range?

Blue and Red

Plastoquinone (PQ), an electron carrier of small molecular weight, is found in the electron transport chain associated with photosystem II. If PQ is not directly anchored to other membrane or cytoplasmic structures, it is probably _____.

Both lipid soluble and a molecule that serves as a shuttle between photosystem II and the cytochrome complex

Why is chlorophyll green?

It absorbs wavelengths in only the blue and red parts of the visible spectrum.

As electrons are passed through the system of electron carriers associated with photosystem II, they lose energy. What happens to this energy?

It is used to establish and maintain a proton gradient.

Light reaction inputs

Light Water NADP+ ADP

The electrons derived from this oxidation reaction in the light reactions are used to reduce ________ to _______ .

NADP+ NADPH

Light reaction outputs

NADPH ATP O2

The Calvin cycle oxidizes the light-reactions product _________ to _______.

NADPH NADP+

Not an input or output of calvin cycle

O2 Glucose Light

How is energy transferred from the reaction center to the electron acceptor?

Redox reactions

A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Since the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. If the power fails and the lights go dark, CO2 levels will _____.

Rise as a result of both animal and plant respiration

Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will most directly affect the _____.

Synthesis of ATP

Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?

The light reactions provide ATP and NADPH to the Calvin cycle, and the Calvin cycle returns ADP, i, and NADP+ to the light reactions.

How are the light-dependent and light-independent reactions of photosynthesis related?

The products of light-dependent reactions are used in light-independent reactions.

What is the main purpose of light-dependent reactions of photosynthesis?

To produce NADPH and ATP

The electrons of photosystem II are excited and transferred to electron carriers. From which molecule or structure do the photosystem II replacement electrons come?

Water