Chapter 8 - Cellular Energetics

Quantum mechanics

________ established that light, a form of electromagnetic radiation, has properties of both waves and particles.

phosphate transporter

The ________ catalyzes the import of one HPO4 2 coupled to the export of one OH.

relative contribution

The ________ of the two components to the total pmf depends on the permeability of the membrane to ions other than H+.

metabolic pathways

All enzyme- catalyzed reactions and ________ are regulated by cells so as to produce the needed amounts of metabolites but not an excess.

free energy

Most of the ________ released during the oxidation of glucose to CO2 is retained in the reduced coenzymes NADH and FADH2 generated during glycolysis and the citric acid cycle.

O2

During electron transport from NADH to ________, protons translocate from the matrix to the intermembrane space; since the outer membrane is freely permeable to protons, the pH of the outside medium is lowered briefly.

glycolytic enzymes

The three ________ that are regulated by allosteric molecules catalyze reactions with large negative △Go, values- reactions that are essentially irreversible under ordinary conditions.

photosynthetic reaction centers

The three- dimensional structures of the ________ from two purple bacteria have been determined, permitting scientists to trace the detailed paths of electrons during and after the absorption of light.

H2O

(2) electron transport leading to the formation of O2 from ________, reduction of NADP to NADPH, and generation of a proton- motive force.

Manganese

________ is known to exist in multiple oxidation states with from two to five positive charges.

small molecules

Most enzymes and ________ involved in the citric acid cycle are soluble in an aqueous solution and are localized to the mitochondrial matrix.

Photorespiration

________ is wasteful to the energy economy of the plant: it consumes ATP and O2, and it generates CO2.

F0F1

The ________ complex, or ATP synthase, has two principal components, F0 and F1, both of which are multimeric proteins.

Succinate dehydrogenase

________ and- ketoglutarate dehydrogenase are integral proteins in the inner membrane, with their active sites facing the matrix.

Glucose metabolism

________ is controlled differently in various mammalian tissues to meet the metabolic needs of the organism as a whole.

oxidative phosphorylation

Although bacteria lack any internal membranes, aerobic bacteria nonetheless carry out ________ by the same processes that occur in eukaryotic mitochondria.

Phosphofructokinase

________- 1 is allosterically inhibited by ATP and allosterically activated by AMP.

aspartate residue

A(n) ________, Asp61, in the center of one of these helices is thought to participate in proton movement.

peroxisome

The ________ is now recognized as the principal organelle in which fatty acids are oxidized in most cell types.

Iron sulfur clusters

________ are nonheme, iron- containing prosthetic groups consisting of Fe atoms bonded both to inorganic S atoms and to S atoms on cysteine residues on a protein.

significant voltage gradient

A(n) ________ can develop only if the membrane is poorly permeable to other cations and to anions, as is the inner mitochondrial membrane.

green leaves

Chloroplasts perform many metabolic reactions in ________.

mesophyll

Because of the transport of CO2 from ________ cells, the CO2 concentration in the bundle sheath cells of C4 plants is much higher than it is in the normal atmosphere.

PSII

In order for ________ and PSI to act in sequence during linear electron flow, the amount of light energy delivered to the two reaction centers must be controlled so that each center activates the same number of electrons.

Chloroplasts

________ are bounded by two membranes, which do not contain chlorophyll and do not participate directly in photosynthesis.

Fatty acids

________ are stored as** triacylglycerols**, primarily as droplets in adipose** (fat- storing) cells**

Enzymes

________ that catalyze the reactions of both the glycolytic pathway and the citric acid cycle are present in the cytosol of bacteria.

large multiprotein complexes

Each of the four ________ in the respiratory chain spans the inner mitochondrial membrane and contains several prosthetic groups that participate in moving electrons.

F0

The ________ component contains three types of integral membrane proteins, designated a, b, and c.