26. Prokaryotes

Organisms that use light for their energy source and CO₂ for their carbon source are called __________.

In an experiment, a microbiologist put equal numbers of each of the following organisms into a flask of sterile broth, consisting mostly of sugar and a few amino acids. She then placed the flask in the dark. Which of the organisms would be most likely to survive?

The Desulfovibrio bacterium breaks down organic matter (which it must have) and uses sulfate (not oxygen) as an electron acceptor. As a result, it produces hydrogen sulfide (H₂S), accounting for the "rotten egg" smell of swamp muck. Oxygen is a deadly poison to Desulfovibrio. We would call Desulfovibrio a(n) __________.

Choose the list below that contains the substances required by typical nitrogen-fixing cyanobacteria.

What do some photosynthetic bacteria use as a source of electrons instead of water?a. oxygen (O2)b. hydrogen sulfide (H2S)c. organic compounds (e.g., CH3COO−)d. nitrate (NO3-)

Photoautotrophs usea. light as an energy source and CO2 as a carbon source.b. light as an energy source and methane as a carbon source.c. N2 as an energy source and CO2 as a carbon source. d. CO2 as both an energy source and a carbon source.

What are organisms called that use inorganic compounds as electron donors in cellular respiration?a. phototrophsb. heterotrophsc. organotrophsd. lithotrophs

What does the chemiosmotic hypothesis claim?a. ATP is generated using phosphates taken from intermediates in the electron transport chain.b. ATP is generated using a phosphate gradient produced by glycolysis and the citric acid cycle.c. ATP is generated using a proton-motive force that is produced by the electron transport chain.d. Water is generated using electrons taken from NADH and FADH2 and transported through the electron transport chain.