BIOL 133 Exam 2

In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the production of which of the following sets of molecules?

ATP< CO2, and acetylCoA

Which of the following statements correctly describes a distinction between autotrophs and heterotrophs?

Autotrophs, but not heterotrophs, ca nourish themselves beginning with CO2 and other nutrients that are inorganic

Which organelle often takes up much of the volume of a plant cell?

Central vacuole

____________ is a regulatory mechanism in which the end product of a metabolic pathway inhibits an enzyme that catalyzes an earlier step in the pathway

Feedback inhibition

Which of the following organelles produces and modifies polysaccharides that will be secreted?

Golgi apparatus

Which of the following is a primary function of the active site of an enzyme?

It catalyzes the reaction associated with the enzyme

Which of the following statements about the electron transport chain is true?

It consists of a series of redox reactions

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

It does not involve organelles or specialized structures, does not require energy, and is present in most organisms

In liver cells, the inner mitochondrial membranes are about 5x the area of the outer mitochondrial membranes. What purpose must this serve?

It increases the surface for oxidative phosphorylation

Which of the following statements best describes the primary role played by oxygen in cellular respiration?

It serves as the final acceptor for electrons from the electron transport chain

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle is most likely defective in this condition?

Lysosome

Which electron carrier(s) function in the citric acid cycle?

NADH and FADH2

The force driving simple diffusion is __________, while the energy source for driving active transport is ___________

a concentration gradient; ATP hydrolysis

Cilia and flagella bend because of __________

a motor protein called dynein

For a protein to be an integral membrane protein, it would have to be __________.

amphipathic, with at least one hydrophobic region

Which of the following molecules dramatically increases the rate of diffusion of water across cell membranes?

aquaporins

How does a noncompetitive inhibitor decrease the rate of an enzyme-catalyzed reaction?

by binding to an allosteric site, thus changing the shape of the active site of the enzyme

Which of the following types of molecules lack hydrophobic domains?

cholesterol

A chemical reaction that has a positive △G is best described as __________

endergonic

Which of the following metabolic processes take place in the cytosol of a eukaryotic cell?

glycolysis and fermentation

In which of the following organisms did the process of photosynthesis most likely originate?

in prokaryotes

A sodium-potassium pump _____________

moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis

Which of the following processes includes all of the others?

passive transport

Which of the following structures form cytoplasmic channels that connect adjacent plant cells through the cell walls?

plasmadesmata

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes ___________

reduced

The oxygen released by photosynthesis is produced by which of the following processes?

splitting water molecules