Which component of animal membranes acts as a temperature buffer, increasing fluidity at

lower temperatures and decreasing fluidity at higher temperatures?

A) phospholipids

B) proteins

C) cholesterol

D) polyunsaturated fatty acids

E) saturated fatty acids

Choose the most complete correct answer from the choices below to finish the sentence:

Protein hormones ____________________________?

A) deliver their message to a receptor in the outer cell membrane (plasma membrane) of the

target cell

B) pass easily through the outer cell membrane of the target cell

C) bind to a gene regulatory protein in the nucleus of the target cell

D) use a signal transduction system to deliver their message to the nucleus of the target cell

E) A and D are both correct

You read about a cell with the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. This could be a cell from

A) a bacterium

B) an animal, but not a plant

C) a plant, but not an animal

D) a plant or an animal

E) any kind of organism

In warm climates, plants have relatively more ______________ than ________________ fats

compared to plants from cold climates.

A) unsaturated; saturated

B) cholesterol; saturated

C) cholesterol; unsaturated

D) saturated; unsaturated

E) polyunsaturated; saturated

How are the membranes of winter wheat able to remain fluid (and therefore functional) when

it is extremely cold? Choose the most complete correct answer from the choices below.

A) by increasing the percentage of cholesterol molecules in the membrane

B) by decreasing the number of proteins in the membrane

C) by increasing the percentage of unsaturated phospholipids in the membrane

D) A and C

E) A, B, and C are all correct

All of the following are functions of proteins found in the animal outer cell membrane

(plasma membrane) except

A) ATP synthesis

B) transport

C) hormone reception and signal transduction

D) enzymatic activity

E) cell-to-cell recognition

Which of the following statements about the cotransport of sucrose and protons (H+) into a plant cell is incorrect?

 

A) sucrose is able to enter the cell against its concentration gradient

B) the higher proton (H+) concentration outside the cell is the result of active (ATP-fueled) transport

C) a substance that prevents protons (H+) from binding to the cotransport protein also prevents the transport of sucrose

D) the protons (H+) are moving through the cotransporter against their concentration gradient

In which of the following would you expect aquaporins to NOT play a role?

A) formation of saliva

B) formation of tears

C) formation of nectar

D) formation of sweat

E) formation of cell walls

Fill in the blank: In order to allow passage of water molecules across biological membranes, the inside channel of the aquaporin protein has to be _____________, and the top and bottom parts of the protein facing the aqueous medium on either side of the membrane have to be ______________.

A) hydrophilic; hydrophilic

B) hydrophobic; hydrophobic

C) hydrophilic; hydrophobic

D) hydrophobic; hydrophilic

Tears consist of water, mucus, and an oil layer. To be able to produce the oil, a tear gland

cell must contain a lot of ________________.

A) ribosomes

B) rough endoplasmic reticulum

C) smooth endoplasmic reticulum

D) Golgi apparatus

E) mitochondria

Which of the following is NOT one of the types of energy-requiring work cells need to perform to stay alive?

A) chemical work (transfer of phosphate to reactant molecules to do chemical work)

B) transport work (transfer of phosphate to transport protein to move substances against their concentration gradient)

C) mechanical work (transfer of phosphate to motor proteins to do mechanical work)

D) hydrolysis work (breakdown of ATP to ADP and phosphate)

Where does glycolysis take place?

A) in the inner fluid space (matrix) of the mitochondrion

B) in lysosomes

C) in the mitochondrial inner membranes

D) in the smooth ER

E) in the cytosol

Cellular respiration harvests the MOST energy from a molecule of glucose under which

conditions?

A) high levels of carbon monoxide

B) low levels of carbon monoxide

C) high levels of oxygen

D) low levels of oxygen

Energy-rich molecules that can be broken down to generate ATP energy in cellular respiration include which of the following? Choose the most  complete correct answer from the choices below.

A) amino acids

B) glycerol

C) glucose

D) fatty acids

E) all of the above

The primary function of the mitochondrion is the production of ATP. To carry out this

function, the mitochondrion must have all of the following except

A) the membrane-bound electron transport chain

B) enzymes for fermentation

C) enzymes for the citric acid cycle

D) mitochondrial ATP synthase

Fill in the blanks: Brown fat cells use energy-rich organic molecules to generate _____________ instead of ____________.

A) carbon dioxide; oxygen

B) oxygen; carbon dioxide

C) ATP; heat

D) heat; ATP

What does the poison cyanide do in mitochondria? Choose the most complete correct answer from the choices below.

A) it inhibits ATP production

B) it causes mitochondrial electron transport to run faster, causing continued breakdown of energy-rich molecules in glycolysis and the citric acid cycle, and release of this energy as heat

C) it stops electron transport and the breakdown of energy-rich molecules, and no heat is generated

D) A and B

E) A and C

If someone offers you a diet pill that promises to burn fat without the need to exercise (and

acts on mitochondrial respiration), the pill is likely to act by

A) binding directly to the ATP synthase, thereby inhibiting ATP formation

B) binding to an electron carrier, thereby blocking electron transport

C) acting as an uncoupler, allowing protons (H+) to leave the intermembrane space without going

through the ATP synthase

What do mitochondria and chloroplasts have in common? Choose the most complete correct

answer from the choices below.

A) electron transport is coupled to proton (H+) transport

B) proton (H+) transport is coupled to ATP production by an ATP synthase protein

C) DNA is present

D) A, B, and C are all correct

Which of the following is the ultimate source of the electrons used to produce NADPH and then used to produce high-energy C-H bonds in sugars from the low-energy bonds in CO2?

 

A) glucose

B) oxygen

C) ATP

D) NADP+

E) water

The beneficial roles of plants for the biosphere and/or for human civilization do NOT include which of the following:

 

A) production of oxygen

B) making the formation of the ozone layer in the atmosphere possible

C) production of food and fuels

D) playing a role in the circulation of nutrients in the biosphere

E) production of carbon dioxide

C3 plants (like poplar) have the advantage of _______________, whereas C4 plants (like switchgrass) have the advantage of _______________.

 

A) being more heat tolerant, needing less water

B) needing less water, being more cold-tolerant

C) being more cold-tolerant, needing less water

Which process in eukaryotic cells is NOT affected by whether oxygen (O2) is present or absent?

 

A) mitochondrial electron transport

B) photosynthetic electron transport

C) ATP production in mitochondria

D) fermentation

Which metabolic process(es) is/are most closely associated with membranes? Choose the most complete correct answer from the choices below.

 

A) ATP generation in mitochondria

B) glycolysis

C) ATP generation in chloroplasts

D) alcohol fermentation

E) A and C

Fill in the blanks: Organic molecules and oxygen are the starting materials in ______________, while carbon dioxide and water are the starting materials in _____________.

 

A) fermentation; photosynthesis

B) photosynthesis; cellular respiration

C) cellular respiration; fermentation

D) cellular respiration; photosynthesis

Fill in the blanks: The structures of mitochondria and chloroplasts are similar in that they both have inner membranes that serve to _____________ and a fluid space with enzymes that serve to _____________.

A) bind the light reactions; convert carbon dioxide to sugars

B) bind ATP synthase proteins; convert sugars to carbon dioxide

C) carry out conversions of carbon-based molecules in a cycle; bind the electron transport chain

D) bind the electron transport chain and ATP synthase proteins; carry out conversions of carbonbased molecules in a cycle

Both mitochondria and chloroplasts produce which of the following? Choose the most complete correct answer from the choices below.

A) ATP

B) sugars

C) oxygen

D) carbon dioxide

E) A and C

Fill in the blanks: The ATP synthase in mitochondria and chloroplasts __________ a proton (H+) gradient, and the ATP-fueled proton (H+) pump on the outer cell membrane (plasma membrane) of plants __________ a proton (H+) gradient.

 

A) creates; creates

B) creates; utilizes

C) utilizes; utilizes

D) utilizes; creates

Which of the following statements best describes the relationship between photosynthesis and respiration?

 

A) photosynthesis occurs only in plants and respiration occurs only in animals

B) ATP molecules are produced in photosynthesis and used up in respiration

C) photosynthesis stores energy in energy-rich molecules, while respiration releases energy from energy-rich molecules

D) respiration generates oxygen, while photosynthesis consumes oxygen

A cell that contains enzymes, DNA, ribosomes, plasma membrane, and mitochondria could be a cell from

A) a bacterium

B) an animal, but not a plant

C) a plant, but not an animal

D) a plant or an animal

E) any kind of organism  

Fill in the blank: To allow passage of water molecules across biological membranes, the outer regions of the aquaporin protein in contact with the membrane have to be ________ and the channel inside the protein has to be ________.

A) hydrophilic, hydrophilic

B) Hydrophobic, hydrophobic

C) Hydrophilic, Hydrophobic

D) Hydrophobic, hydrophilic 

The large tear gland is responsible for generating the oil later. What feature of eukaryotic cells is found in greater abundance in the secretorycells of the large tear gland?

A) rough ER

B) smooth ER

C) Golgi apparatus

D) Mitochondria  

Which of thefollowingare needed in the human body as anitoxidant mineral?

A) Zinc (Zn)

B) Selenium (Se)

C) Potassium (K)

D) only A and B

E) A, B, and C 

A diet in antioxidants has been linked to the following diseases or conditions

A) cancer

B) heart disease

C) infertility

D) only A and B

E) A, B, and C 

Which process does NOT lead to the formation of potentially harmful reactive oxygen in the human body?

A) the breakdown of alcohol

B) the synthesis of phospholipids

C) mitochondrial respiration

D) the immune response

E) exposure to asbestos or silica dust  

Fill in theblanks: In photosynthesis, the light reactions provide _______ to the Calvin Cycle, and the Calvin cycle returns _______ to the light reactions.

A) ATP and NADPH; ASP, Pi and NADP+

B) ATP and NADPH; water and electrons

C) Carbon dioxide; sugars for ATP production

D) oxygen; water to split      

Which one of the following is the ultimate source of the electrons used to produce NADPH and then used to produce high energy C-H bonds in sugars from low energy bonds in CO2?

A) o2

B) ATP

C) NADP+

D) H2O

E) glucose

 

Which of the following are produced by light collecting and electron transport reactions in photosynthesis and are utilized in the Calvin Cycle?

A) CO2 and glucose

B) H2O and O2

C) ADP and NADP+

D) photons and H20

E) ATP and NADPH 

Which process in eukaryotic cells is NOT affected by whether oxygen is present or absent?

A)Mitochondrial electron transport

B)photosynthetic electron transport

C)ATP production in mitochondria

D)fermentation

Organic molecules and oxygen are thestarting materials in ______, while carbon dioxide and water are the starting materials in ________.

A) fermentation; photosynthesis

B) photosynthesis; cellular respiration

C) Cellular respiration; fermentation

D) cellular respiration; photosynthesis

Both mitochondria and chloroplasts prodduce which of the following? Choose the most complete correct answer.

A) ATP
B) sugars
C) Oxygen

D) carbon dioxide
E) A and C

The ATP synthase in mitochondria and chloroplasts _______ a proton(H+) gradient, and the ATP-fueled protong (H+) pump on the outer cell membrane (plasma membrane) of plants ______ a proton (H+) gradient. 

A) creates; creates

B) creates; utilizes
C) utilizes; utilizes

D) utlizes; creates

Which type of fatty acid would offer the greatest benefit for membranes of plants, algae and bacteria in the coldest habitats on earth?

A) saturated
B) monounsaturated
C) polyunsaturated

 

Which type of fatty acid would be more abundant in the membranes of plants, algae and bacteria in cold environments?

A) saturated

B) unsaturated 

Which type of fatty acid would be more abundant in the membrane phospholipids of plants, algae and bacteria from hto environments?

 

A) saturated

B) monunsaturated

C) polyunsaturated  

What changes occur in membranes of a plant in Colorado that grows throughout the hot summer season and overwinters during the cold winter?

A) The fatty acid composition will not change between seasons

B) The proportion of unsaturated fatty acids will be higher in the summer and then decrease in the winter

C) The proportion of saturated fatty acids will be higher in the summer and then decrease in the winter 

Which of the following statements about the cotransport of sucrose and protons (H+) is INCORRECT?

A) sucrose is able to enter the cell against its concentration gradient

B) the higher proton (H+) concentration outside the cell is the result of active (ATP fueled) transport

C) a substance that prevents protons from binding to the cotransport protein also prevents the transport of sucrose

D)the protons are moving through the cotransporter against their concentration gradient  

Water moves from _____ to _____ without requiring ATP energy

A) Low salt concentration, high salt concentration

B) High sal concentration; low salt concentration

C) High water concentration, low water concentration

D) A and C

E) B and C 

Which hormone can pass through membrane lipid bilayer?

 

A) Protein hormones

 

B) Steriod hormones 

Which of the following statements regarding ATP is/are correct?

A) ATP serves as a main energy carrier inside cells.

B) ATP drives energy-consuming reactions in the cell by the transfer of a phosphate group to specific reactants

C) The regeneration of ATP from ADP and phosphate is an energy-consuming reaction

D) A and B

E) A, B, and C 

Which of the following does NOT have the same structural components as all of the other molecules?

A) ATP

B) NADH
C) DNA
D) steroids

E) nucleotides 

Cellular respiration harvests the MOST chemical energy from which of the following?

A) glycolysis

B) fermentation

C) generating carbon dioxide and oxygen in the mitochondrial electron transport chain

D) the mitochondrial part of cellular respiration (citric acid cycle, electron trasnport, and ATP synthase) 

Molecules that can potentially be converted to intermediates of glycolysis and/or the citric acid cycle include

A) amino acids and proteins

B) glycerol and fatty acids

C) glucose and sucrose

D) starch and glycogen

E) all of the above  

Cells release the energy or energy-rish food molecules. Which one of the steps below represents a change from one form of energy to another?

A) use of energy-rich electrons to build up a proton gradient

B) use of the proton gradient to drive ATP formation

C) use of an uncoupling protein for thermogenesis

D) All of the above