Biology Lab 6,7

How many turns of the Calvin cycle are required to produce one molecule of glucose?

6

In the first stage of cellular respiration (glycolysis), two molecules of pyruvate are produced. In the remaining stages of cellular respiration, a number of additional products are produced, such as __________. These other stages occur in the __________.

ATP ... mitochondria

In simple summary form, the input of the Calvin cycle for every product is __________, and the output is __________ used for glucose synthesis.

3 CO2 ...; a three-carbon molecule

The overall efficiency of respiration is approximately _________

34%

Substrate-level phosphorylation directly generates ATP during a chemical reaction. As a single molecule of glucose is completely oxidized in the presence of oxygen, what is the net yield of molecules of ATP made by substrate-level phosphorylation?

4 ATP

In cellular respiration, which of the following outcomes is the result of electrons moving through the electron transport chain (or its components)?

A proton gradient is formed.

Which statement regarding the light reactions is true?

Electrons are supplied to chlorophyll P680 as it reduces the primary electron acceptor.

Which of the following statements regarding aerobic cellular respiration is TRUE?

Glucose is completely oxidized to form carbon dioxide.

What happens to the energy that is released by electrons as they move through the electron transport chain?

It pumps H+ through a membrane.

As shown below, an electron carrier, such as __________, acts as an energy-storage molecule when it is __________.

NADH ... reduced

Consider the figure below. __________ is to a mitochondrion as __________ is to a chloroplast.

O2 ... CO2

CAM plants have adapted to arid environments by closing their stomata during the day. However, photosynthesis still occurs. This is because

O2 is fixed at night when the stomata are open

Current evidence indicates that the process of photosynthesis arose more than three billion years ago. Its origin had a huge impact on existing organisms and on the physical characteristics of the biosphere. Which major physical change could be attributed to photosynthesis?

Photosynthesis drastically increased the oxygen content of the atmosphere.

Hydrogen is a likely candidate in the search for a replacement for petroleum. However, removing hydrogen from water requires the investment of a great deal of energy. Why are plants considered to be one step ahead in the utilization of hydrogen as an alternative fuel source?

Plant cells possess water-splitting enzymes.

Although the reactions of the Calvin cycle are not directly dependent on light, they usually do not occur at night. Why?

The Calvin cycle depends on products of the light reactions.

A large research project was carried out in the oceans surrounding Antarctica to learn whether adding iron-containing compounds to the iron-limited polar sea would enhance the growth of phytoplankton (small, free-floating photosynthetic organisms). This project was performed with the hope that if plankton growth were significantly increased over large areas, it might slow global warming. What is the basis for such an expectation?

The increased biomass will act as a sponge (a carbon sink) for atmospheric carbon dioxide.

Through respiration, humans breathe in O2 and breathe out CO2. However, what would happen if we did not breathe in O2?

We would not make enough ATP to meet our energy requirements

You have a large, healthy philodendron that you carelessly leave in total darkness while you are away on vacation. You are surprised to find that it is still alive when you return. What has the plant been using for an energy source while in the dark?

While it did have access to light before you left, the plant stored energy in the form of sugars or starch, and it was able to derive energy from those during your vacation.

Which of the following colors of light are useful during the process of photosynthesis?

blue, red, and violet

Considering the wavelengths of light shown below, the pigments in the granum absorb mainly in which range?

blue-violet and red-orange

The O2 required for __________ is supplied by __________.

breathing ... cellular respiration

A small amount of ATP is made in glycolysis _____.

by the transfer of a phosphate group from a fragment of glucose to ADP (substrate-level phosphorylation)

The most important role of pigments in photosynthesis is to _____.

capture light energy

In the Calvin cycle carbon dioxide provides _____, whereas ATP and NADPH provide _____ and _____, respectively.

carbon ... energy ... high-energy electrons

In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive carbon. The mice were closely monitored, and in a few minutes, radioactive carbon atoms showed up in __________.

carbon dioxide

In nutrient-rich environments (like your mouth), bacteria can use the provided amino acids to synthesize their proteins. However, should the environmental conditions change and become nutrient-poor, bacteria would need to synthesize their amino acids. They can do this using __________.

citric acid cycle intermediates

Which of the following are photoautotrophs?

corn stalks just before harvest

The conversion of NADP+ to NADPH occurs with the assistance of __________.

electrons from water and energy from sunlight

Cellular respiration completely breaks down a glucose molecule through glycolysis and the citric acid cycle. However, these two processes yield only a few ATPs. The majority of the energy the cell derives from glucose is _____.

found in NADH and FADH2

Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________.

four; 3 NADH and 1 FADH2

The primary function of light absorption by photosystems I and II is to produce __________.

free, energized electrons

You could distinguish a granum from an inner mitochondrial membrane because the granum, but not the inner mitochondrial membrane, would _____.

have photosynthetic pigments

Solar radiation warms the surface of the planet and then is radiated back in the form of __________.

heat

A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to treat people with bacterial infections. However, he can't do this because _____

human cells also perform glycolysis; the drug might also poison them

C4 and CAM plants have adapted to living in environments where water loss is a problem. C4 plants fix carbon dioxide _____, whereas CAM plants fix carbon at _____.

in different locations ... different times of the day

Where does glycolysis occur in a eukaryotic cell?

in the cytoplasmic fluid

When a car engine burns gasoline, the results of the reaction are similar to when cells burn glucose. Both reactions release carbon dioxide and water. In cells, the chemical energy in food is converted to ATP and heat. In a moving car, the chemical energy in gasoline is converted to __________.

kinetic energy and heat

A molecule is oxidized when it __________.

loses an electron

A molecule that functions as the electron donor in a redox reaction __________.

loses electrons and becomes oxidized

The electron transport chain is a series of electron carrier molecules. In eukaryotes, where can this structure be found?

mitochondria

The reaction center, antenna molecules, and primary electron acceptors that cluster in the thylakoid membrane form which structure?

photosystem

Glycolysis is the only stage of cellular respiration that __________.

requires ATP to make ATP

Carbon dioxide enters a leaf through the _____.

stomata

The photosynthetic event known as the Calvin cycle occurs in the __________.

stroma

Most NADH molecules generated during cellular respiration are produced during __________.

the citric acid cycle

Sunlight is essential for the varied life on Earth. Sunlight provides energy to photosynthetic organisms by providing __________.

the energy necessary to power the rearrangement of chemical bonds in H2O and CO2

The enzyme ATP synthase catalyzes the phosphorylation of ADP to form ATP. In eukaryotic cells, the energy needed for this endergonic reaction is directly derived from __________.

the movement of hydrogen ions across the mitochondrial membrane

When chloroplast pigments absorb light, _____.

their electrons become excited

Chlorophyll molecules are found in which part of the chloroplast?

thylakoid membrane

Chlorophyll is found in the __________ of chloroplasts.

thylakoid membranes