Kapitel 2 Flashcards Preview

Molecular Biology of the Cell > Kapitel 2 > Flashcards

Flashcards in Kapitel 2 Deck (43)
Loading flashcards...

Force exerted by the hydrogen-bonded network of water molecules that brings two nonpolar surfaces together by excluding water between them. (Panel 2–3 - pp. 94–95)

hydrophobic force


Polymers constructed of long chains of covalently linked - small organic (carbon-containing) molecules. The principal building blocks from which a cell is constructed and the components that confer the most distinctive properties of living things.



The sum total of the chemical processes that take place in living cells. All of catabolism plus anabolism. (Figure 2–14)



Electron carrier system that participates in oxidation–reduction reactions - such as the oxidation of food molecules. NAD+ accepts the equivalent of a hydride ion (H– - a proton plus two electrons) to become the activated carrier NADH. The NADH formed donates its high-energy electrons to the ATP-generating process of oxidative phosphorylation. (Figure 2–36)

NAD+/NADH (nicotinamide adenine dinucleotide/reduced nicotinamide adenine dinucleotide)


Electron carrier system closely related to NAD+/NADH - but used almost exclusively in reductive biosynthetic - rather than catabolic - pathways. (Figure 2–36)

NADP+/NADPH (nicotinamide adenine dinucleotide phosphate/reduced nicotinamide adenine dinucleotide phosphate)


Biochemical process carried out by certain bacteria that reduces atmospheric nitrogen (N2) to ammonia - leading eventually to various nitrogen-containing metabolites.

nitrogen fixation


Loss of electrons from an atom - as occurs during the addition of oxygen to a molecule or when a hydrogen is removed. Opposite of reduction. (Figure 2–20)

oxidation (verb oxidize)


Common measure of the acidity of a solution: “p” refers to power of 10 - “H” to hydrogen. Defined as the negative logarithm of the hydrogen ion concentration in moles per liter (M). pH = –log [H+]. Thus a solution of pH 3 will contain 10–3 M hydrogen ions. pH less than 7 is acidic and pH greater than 7 is alkaline.

pH scale


Positively charged subatomic particle that forms part of an atomic nucleus. Hydrogen has a nucleus composed of a single proton (H+).

proton (H+)


Addition of electrons to an atom - as occurs during the addition of hydrogen to a biological molecule or the removal of oxygen from it. Opposite of oxidation. (Figure 2–20)

reduction (verb reduce)


Polysaccharide composed exclusively of glucose units - used as an energy-storage material in plant cells. (Figure 2–51)



Molecule on which an enzyme acts.



Type of (individually weak) noncovalent bond that is formed at close range between nonpolar atoms. (Table 2–1 - p. 45 and Panel 2–3 - pp. 94–95)

van der Waals attraction