BIOL 1010 - Midterm Review - Ch. 8

The human eye can detect light wavelengths between ____ and ____ nm, which represent that range of the visible spectrum.

380 740

The 2 following components of both PSI and PSII are?

A reaction center A light harvesting complex

The Calvin cycle uses ____ and ____, which are products of the light reactions of photosynthesis

ATP and NADPH

The electron transport chain directly associated with PSII is used to generate ____, while the electron transport chain directly associated with PSI is used to generate ____.

ATP; NADPH

When NADP+ ____ electrons in the light reactions, it is ____, forming NADPH

Accepts Reduced

Which of these herbicides (H - 1 to H - 5) works by binding to chlorophyll and preventing light absorption?

Answer: H - 2 --> Chlorophyll absorption (Decrease) Oxygen production (Decrease) NADPH production (Decrease) ATP Synthase activity (Decrease) G3P production (Decrease)

Which of these herbicides (H-1 to H-5) works by inactivating an enzyme in the Calvin cycle that normally produces G3P?

Answer: H-4 --> Chlorophyll absorption (no change) Oxygen production (no change) NADPH production (no change) ATP Synthase activity (no change) G3P production (Decrease)

Organisms that can carry out photosynthesis?

Bacteria Plants Algae

In some plants, carbon fixation yields a four-carbon molecule instead of 3GP as the first product. Such plants are known as ____ plants.

C4

____ 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.

What molecule is reduced during the process of photosynthesis?

Carbon dioxide

What is the purpose of the light reactions of photosynthesis?

Conversion of light energy to chemical energy (in the form of ATP and NADPH)

Heterotroph

Must consume food to obtain organic molecules

Which of the following are products of the light reactions that are used by the Calvin cycle to make carbohydrates?

NADPH and ATP

What is the product of the oxidation of water during photosynthesis?

O2

The light reactions of photosynthesis produce three chemical products:

Oxygen NADPH ATP

One species of photosynthetic bacteria uses sulfide as its final electron acceptor, thus creating H2S. This means that

Oxygen is not produced by photosynthesis in this bacterium

The process by which plants capture light energy and use it to synthesize glucose and other organic molecules is called

Photosynthesis

Cyanobacteria, green sulfur bacteria and purple sulfur bacteria all use photosystems and electron transport chains when they carry out photosynthesis. From this you can conclude

Photosynthetic pathways are similar and arose from a common ancestor

What happens during photosynthesis?

Plants capture energy from sunlight and use it to synthesize organic molecules (carbohydrates)

Autotroph

Produces organic molecules from inorganic molecules

A new flower species has flowers that are red. What wavelengths of light does this flower reflect?

Red

What happens during photorespiration?

The enzyme Rubisco attaches O2 to RuBP, and CO2 is produced.

The light independent reactions of photosyntheses require NADPH. Where does this molecule come from?

The light dependent reactions

The light reactions of photosynthesis take place in the ____ membrane, while the Calvin cycle occurs in the ____ of the chloroplast.

Thylakoid Stroma

What is the overall goal of photosynthesis?

To use solar energy to make glucose

Photoautotroph

Uses light energy to drive the synthesis of organic molecules from inorganic molecules

During photosynthesis in green plants, what molecule is oxidized?

Water

Which of the following conditions affect the way the Calvin cycle operates in photosynthetic organisms?

Water availability Temperature Light intensity

In C4 plants, the first product of carbon fixation is:

a four-carbon molecule

A pigment is a molecule that can:

absorb light

which portion of the photosynthetic apparatus absorbs light?

both photosystem I and photosystem II

The oxidization of water by photosystem II causes the pH of the thylakoid lumen to

decrease

As water is oxidized during photosynthesis, the pH of the thylakoid lumen:

decreases (reason: H+ accumulates in the thylakoid lumen, making the space very acidic.)

In photosynthesis, glucose is synthesized from CO2. This reaction is:

endergonic

The cyclic pathway of photosynthesis produces

energy only

The photosynthetic light reactions are composed of a series of:

energy transfers

During photosynthesis, CO2 is reduced to produce

glucose

____ genes are similar to each other because they are derived from the same ancestral gene.

homologous

The ____ reactions of photosynthesis are composed of a series of energy changes.

light

PSI and PSII have two main components: a(n) ____ harvesting complex and a(n) ____ center.

light reaction

The light reactions convert ____ energy into ____ energy stored in covalent bonds.

light (solar) chemical

a small amount of ATP is actually made during photosynthesis. When does this occur?

light dependent reactions

Sunlight provides the ____ ____ that is necessary for the synthesis of glucose from carbon dioxide.

light energy

What are the two stages of photosynthesis?

light reactions and calvin cycle

The splitting of water in photosystem II results in the production of ____ gas.

oxygen

In hot dry conditions, rubisco can attach O2 to RuBP in a process called ____, which ultimately produces CO2.

photorespiration

In the reaction, 6CO2 + 6H2O →C6H12O6 + 6O2, carbon dioxide is being ____

reduced

In the generalized equation for photosynthesis, the transfer of electrons occurs such that CO2 is ____ and H2O is ____.

reduced oxidized

In cyanobacteria, the Calvin cycle occurs in the ____ of the cells.

stroma

In plants and algae, the Calvin cycle occurs in the ____ of chloroplasts.

stroma

During photosynthesis, oxygen is produced by:

the removal of electrons from water in PS2 (water is oxidized)

The energy for producing organic molecules in plants is directly driven by

the use of light to provide electron for oxidation and reduction reactions

Homologous genes are similar to one another because:

they are derived from the same ancestral gene

Why are leaves green?

they reflect green light

The ____ membrane of the chloroplast contains two independent, light capturing complexes of proteins and pigments called photosystems I and II.

thylakoid

In the light reactions, both photosystems absorb and capture light energy in the form of excited electrons; however PSII is able to oxidize ____ , which results in the production of oxygen.

water

When you see the color of an object this means that the photons of that wavelength

were reflected by the molecules

The energy required for the synthesis of glucose from carbon dioxide ultimately comes from

Light (solar energy)

What energy conversion occurs during photosynthesis?

Light energy is converted to electrochemical energy, which is converted to chemical energy (reason: Breaking the high energy bonds of carbohydrates releases chemical energy.)

True or false: All photons contain the same amount of energy.

False (Reason: Each photon carries a specific amount of energy that depends on its wavelength.)

True or false: Glucose is the primary output of the Calvin cycle.

False (reason: The primary output of the Calvin cycle is G3P, which can be used for glucose synthesis in another set of reactions.)

What is the function of chlorophyll during photosynthesis?

It absorbs light energy.

The source of carbon for the carbohydrates synthesized in the Calvin cycle is ____ from the atmosphere.

carbon dioxide

Green plants utilize ____ a and b to absorb light energy in photosynthesis.

chlorophyll

Plants appear green because they contain:

chlorophyll