chapter 7 how cells harvest energy assignment and chapter 8 photosynthesis

Under anaerobic conditions, the end-product of glycolysis is converted to

lactic acid

If a mutation arose in the cytochrome/b6-f complex, making it completely nonfunctional, what would be the immediate result?

Light energy could not be harnessed to generate ATP in the cells containing the mutation.

Some bacteria only use one photosystem. How does this differ from photosynthesis in green plants?

Photosynthesis in these bacteria does not produce oxygen.

In green plants, what is the sequence of photosystems, and what does each photosystem produce?

Photosystem II → O2 production → Photosystem I → NADPH production

What would be the immediate consequence if all of the glyceraldehyde 3-phosphate made during the carbon fixation and reduction phases of the Calvin cycle were used to make glucose?

Plant cells would not be able to regenerate RuBP.

In 1771, Joseph Priestly conducted an experiment where he put a living mint spring into a glass container with a lit candle. This container was then closed so that air could not escape or enter. Once inside the closed container, the candle burned for a certain period of time, and then went out. After approximately one month, Priestly attempted to re-light the candle inside the closed container using a mirror to focus sunlight onto the wick. He was successful in lighting the candle again using this approach. What do the results of this specific experiment allow you to conclude about plants?

Plants can generate oxygen.

Why don't plants use UV light in the process of photosynthesis?

UV light has too much energy and can be detrimental to the plant.

Organisms that can manufacture their own chemical energy are called ____________.

autotrophs

Light consists of units of energy called

photons

Creation of a proton gradient by the electron transport chain represents.

potential energy

If sunlight is the source of energy for most organisms on earth, how are humans and other animals able to utilize this energy if they cannot photosynthesize? Trace the flow of energy in order from source to destination.

sun-plant-animal-human

Many, but not all, plants are green in color. A Japanese maple, for instance, uses dark red leaves for photosynthesis. What can you infer about the light color used by a Japanese maple for photosynthesis?

the Japanese maple tree transmits or reflects red light

NADPH is made as a result of

the electron transport chain that follows photosystem I.

Several processes that occur along the mitochondrial electron transport chain are required to generate a proton gradient. Which of these processes directly involves a proton pump?

the movement of h+ through cytochrome oxidase

Which of the following choices is not associated with a redox reaction in the Kreb's cycle?

the production of Acetyl-CoA

When yeast cells metabolize glucose in the absence of oxygen, which of the following are true? Check all that apply.

- all atp is made by substrate level phosphorylation -glycolysis occurs -ethanol is produced - NAD+ is regenerated from NADH - they produce less ATP than they produce in aerobic conditions

Aerobic Respiration

- generates the most ATP - is a process carried out by humans

Anaerobic Respiration

- uses sulfate as an oxidizing agent - one of the products of this process can be methane gas

A single "turn" of the Krebs cycle will yield

1 ATP, 3 NADH, 1 FADH2

Arrange the electron acceptors in order from highest to lowest energy. 1 = Cytochrome C 2 = Oxygen 3 = Cytochrome C oxidase

1,3,2

The net result of a single round of glycolysis is the formation of

2 NADH and 2 ATP

The initial reaction of the Krebs cycle involves the addition of a

2-carbon molecule to a 4-carbon molecule

Which best represents the overall equation for photosynthesis?

6 CO2 + 12 H2O + Light energy → C6H12O6 + 6 O2 + 6 H2O

Which statements about the products of glycolysis is TRUE? (Check all that apply)

A cell may either oxidize or reduce pyruvate, depending on cellular conditions the production of ATP in Glycolysis is an exergonic reaction

In animals that take in oxygen from their environment, glucose is broken down into carbon dioxide and water in a process called

Aerobic respiration

Where does the energy directly come from that is used to convert low-energy, inorganic CO2 into the high-energy, organic carbon in sugar?

ATP and NADPH

Carbon dioxide (CO2) is produced during aerobic respiration. Which statement is TRUE?

CO2 is often the product when an organic molecule is oxidized

Tropical rainforests are being destroyed by commercial logging at an alarming rate. When these forests are destroyed, they do not easily regrow. What is one issue that could result from the destruction of these forests?

Destroying these forests could lead to decreased production of oxygen worldwide.

All types of bacteria that can do photosynthesis make use of only one photosystem.

False

Electrons are brought to the electron transport system by the oxidation of

NADH and FADH2

If all purple nonsulfur bacteria on the planet were to go extinct, what would be the effect on our environment?

Neither oxygen nor water levels in the atmosphere would change.

In photosynthesis, the carbon in CO2 is initially fixed to what molecule?

RuBP

What molecule would be most directly affected if two CO2 molecules could be fixed at the same time?

RuBP

If one P680 reaction center complex in a plant were damaged, the overall effect on the plant would mean it would not be able to

The plant would be unaffected for the most part if only one P680 reaction center complex were damaged.

If a plant lacked all pigments, how would this affect the Calvin cycle?

The Calvin cycle would not run in the absence of pigments.

If the gene encoding a specific enzyme in the plastoquinone biosynthetic pathway were mutated in a particular cell such that it became completely nonfunctional, what immediate effect would that have on that cell?

The cell would be unable to use light energy to make ATP.

How does an electron transport chain lead to the generation of ATP in the light-dependent reactions of photosynthesis?

The movement of electrons down the electron transport chain drives the formation of a protons gradient that is used to make ATP.

Why are green plants green in color?

They contain a pigment that transmits and reflects green light.

If there is a mutation in one of the genes encoding a component of the P700 reaction center complex such that all copies of this complex are nonfunctional in a particular bacterial cell, what would be the result?

This bacterial cell would not be able to harness light energy to form NADPH.

If a drug existed that could make the thylakoid membrane permeable to protons, how would this affect the plant's ability to make sugar?

This drug would decrease the ability of the plant to make sugar.

what is produced by a proton pump?

a concentration gradient

Chlorophyll is the main pigment found in plants. Other pigments are also present. If these other pigments were lost from a plant, but chlorophyll remained, the plant would no longer be able to

absorb wavelengths of light outside those absorbed by chlorophyll.

Before entering the Krebs cycle, pyruvate is converted to

acetyl - CoA

What is a final electron acceptor in the electron transport chains of organisms that conduct anaerobic respiration?

carbon dioxide

Synthesis of ATP via a proton gradient is called

chemiosmosis

What molecule/complex would not be found in the stroma?

chlorophyll

In eukaryotes, photosynthesis takes place inside ________.

chloroplasts

To form NADH from NAD+, two electrons and a proton are removed from an organic molecule. What term best describes the reaction in which electrons and a proton are removed from an organic molecule?

dehydrogenation

What replaces the electrons excited by sunlight in photosystem I?

electrons from photosystem II

If the gene encoding the enzyme rubisco is mutated such that the enzyme is nonfunctional, the process(es) that would be affected is/are the ability to

generate o2 fix carbon absorb light make NADPH make ATP

In cellular respiration, what pathway directly generates ATP for the cell?

glycolysis

When cells possess plentiful amounts of ATP, what happens to cellular respiration processes within the cell?

glycolysis is slowed

Why are two ATP required during the first phase of glycolysis?

in order to create a high energy molecule that will spontaneously split into two 3-carbon molecules

The movement of protons through ATP synthase occurs from the

intermembrane space to the matrix

both aerobic and anaerobic respiration

involves glycolysis involves the krebs cycle makes use of an electron transport chain

In the reaction: C3H7O6P + NAD+ → C3H8O10P2 + NADH, what happened to the NAD+?

it was reduced

If the only organisms on Earth that perform photosynthesis were bacteria with only one photosystem, which perform cyclic photophosphorylation, would the resulting environment be capable of supporting animal life as we know it?

no, because cyclic photophosphorylation does not lead to the generation of oxygen

Are the carbons in glucose ultimately used to make additional Krebs cycle intermediates?

no, though two carbons are added into the krebs cycle in the form of acetyl-CoA, two carbons are lost in the form of two molecules of CO2 as the krebs cycle progresses

Which of the following is the enzyme used to synthesize ATP?

none of these choices are correct

The products of photosynthesis are

o2 and glucose

The light-dependent reactions synthesize NADPH and oxygen using _________ process(es).

oxidation and reduction

You have a suspension of chloroplasts with thylakoid membranes that are permeable to protons. Which stage(s) of the light-dependent reactions will not occur in these chloroplasts?

primary photoevent charge separation electron transport chemiosmosis

Which statement describes the role of a proton pump in energy conversion?

proton pumps convert energy from a redox reaction into an electromagnetic gradient

In glycolysis, glucose is converted to

pyruvate

You would like to study the activity of glycolysis in a cell undergoing cellular respiration in the presence of ample oxygen. Assuming you could experimentally measure the level of any product of cellular respiration, which product would you want to measure to determine the output of glycolysis?

pyruvate

Where does the Calvin cycle take place?

stroma

In noncyclic photophosphorylation, the electrons passed down through the electron transport system are ultimately obtained from

water

Per molecule of glucose, how many molecules of NADH are generated by pyruvate oxidation?

2

Why is formation of ATP by ATP synthase in the mitochondria known as oxidative phosphorylation?

a proton gradient created by the redox reactions of the electron transport chain is used to drive the synthesis of ATP

NADH is produced in glycolysis by the reduction of NAD+. Which statement is TRUE regarding the production of NADH during glycolysis?

another molecule was oxidized in order to reduce NAD+

Carbon dioxide and water can combine to form glucose, water and oxygen. What is required for that process to occur?

light energy from the sun

One common feature of electron carriers such as NAD+ is that

they can be reversibly oxidized and reduced