Mastering Biology chapters 7 and 8

The complete oxidation of two molecules of glucose (C6H12O6) in cellular respiration produces about how many molecules of ATP?

60-64

In the citric acid cycle (see the figure), beginning with one molecule of isocitrate and ending with fumarate, how many ATP molecules can be made through substrate-level phosphorylation?

1

How many carbon atoms from one molecule of pyruvate enter the citric acid cycle?

2

How many molecules of oxygen (O2) are consumed by the complete oxidation of glucose (C6H12O6) to carbon dioxide and water in aerobic respiration?

6

What are the products of linear electron flow?

ATP and NADPH

Yeast cells grown anaerobically can obtain energy by fermentation, which results in the production of

ATP, CO2, and ethanol.

During intense exercise, as human muscle cells switch from respiration to fermentation, the cells will increase their catabolism of which of the following energy-containing molecules?

Carbohydrates only

Which of the following statements correctly describes a reaction associated with photosystem II?

Electrons released from the P680 chlorophyll are replaced by electrons derived from water.

During strenuous exercise, human muscle cells can become oxygen-deprived. When this occurs, muscle cells perform anaerobic fermentation, which results in the production of lactate from pyruvate. What happens to the lactate produced in muscle cells?

It is taken to the liver and converted back to pyruvate

Which of the following statements correctly describes an activity directly associated with photosystem I?

It receives electrons from the electron transport chain associated with thylakoid membranes.

Energy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells?

Mitochondria inter membrane space

Which of the following statements about NAD+ is true?

NAD+ is reduced to NADH during glycolysis

In addition to ATP, what are the products of glycolysis?

NADH and pyruvate

Which of the following products of the light reactions of photosynthesis is used during the Calvin cycle?

NADPH

If plants are grown with H2O containing a radioactive isotope of oxygen (18O), subsequent analysis will show that 18O first appears in which of the following molecules produced by the plants?

O2

In most cells, not all of the carbon compounds that participate in glycolysis and the citric acid cycle are converted to carbon dioxide by cellular respiration. What happens to the carbon in these compounds that does not end up as CO2?

The carbon compounds are removed from these processes to serve as building blocks for other complex molecules.

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, Pi, and NADP+ to the light reactions.

Carotenoids are found in several foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants?

They absorb and dissipate excess light energy that might otherwise react with oxygen to form harmful oxidative molecules.

A spaceship designed to support human life for a multiyear voyage to the outer planets of the solar system will include plants to provide oxygen and consume carbon dioxide. Because the spaceship will have limited exposure to the sun for extensive periods, an artificial light source will be needed to support photosynthesis. What wavelengths of light should be used to maximize plant growth with a minimum expenditure of energy?

a combination of blue and red light

Which one of the following molecules is formed by the removal of a carbon (as CO2) from a molecule of pyruvate during aerobic respiration?

acetyl CoA

A gardener is concerned that her greenhouse is getting too hot from too much light. She plans to shade her plants with colored translucent plastic filters that allow only a narrow part of the visible light spectrum to pass through. To reduce the overall light energy but still maximize plant growth, she should use a filter that allows the passage of which of the following colors of light?

blue

Generation of proton gradients across membranes occurs during which of the following reactions?

both photosynthesis and cellular respiration

The photosynthetic membranes are found in the _____ in plant cells.

chloroplast

Inside an active mitochondrion, most electrons follow which of the following pathways?

citric acid cycle →→ NADH →→ electron transport chain →→ oxygen

In mitochondria, the electron transport chain pumps protons from the matrix into the intermembrane space. In what direction are protons pumped by the electron transport chain in chloroplasts?

from the stroma to the thylakoid space

In chemiosmosis in mitochondria, protons flow from the intermembrane space into the matrix. In what direction do protons flow during chemiosmosis in chloroplasts?

from the thylakoid space to into the stroma

Which of the following metabolic processes in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?

glycolysis

Which of the following metabolic pathways occur(s) in the cytosol of eukaryotic cells?

glycolysis and fermentation

The oxygen atoms used to form water in the complete reactions of cellular respiration are derived from which of the following molecules?

molecular oxygen (O2)

Which of the following metabolic processes produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water?

oxidative phosphorylation (chemiosmosis)

Photophosphorylation in photosynthesis is most similar to which of the following processes associated with cellular respiration?

oxidative phosphorylation in mitochondria

Photosynthesis is a redox reaction. H2O is _____ during the light reactions and CO2 is _____ during the Calvin cycle.

oxidized... reduced

What is the source of the energy used to generate the proton gradient across the inner mitochondrial membrane?

redox reactions in the electron transport chain

Which of the following reactions produces the oxygen released by photosynthesis?

splitting of water molecules

Where do the enzymatic reactions of the Calvin cycle take place?

stroma of the chloroplast

Plants are photoautotrophs. What does this mean?

they use light energy to drive synthesis of organic molecules from inorganic materials

Where is the electron transport chain associated with photophosphorylation located in plant cells?

thylakoid membranes of chloroplasts

What is the primary function of the Calvin cycle?

to produce simple sugars from carbon dioxide

Which of the following is the most important result of the process of cellular respiration in biological systems?

transforming the energy in glucose and related molecules in a chemical form that cells can use for work

The electrons stripped from glucose in cellular respiration end up in which compound?

water