Energy College Biology Flashcard

The ATP molecule is the __________ currency of the cell.

• energy

• storage

• communication

• security

Answer explanation

(Adenosine Triphosphate). In other words, the basic molecule used to convey energy in a cell is the ATP molecule.

The ATP molecule transfers energy from __________ bonds to energy-absorbing ( endergonic ) reactions in the cell.

• Monomer

• covalent

• hydrogen

• chemical

Answer explanation

The opposite, energy-releasing reactions that occur spontaneously are termed 'exergonic' reactions.

The covalent bond between the second and third phosphate group of the ATP molecule, which stores the greatest amount of energy (approximately __________ kcal/mole) is known as the pyrophosphate bond.

• five

• seven

• eleven

• nine

Answer explanation

The breakdown of ATP produces:


Adenosine diphosphate (ADP) + energy + inorganic Phosphate (Pi)



By adding energy, ADP can be 'recharged' like a battery into ATP.

Glycolysis, or the 'universal energy pathway', is a form of __________ in which glucose is broken down step by step in a series of nine enzymatic reactions. All organisms have this reaction occuring in their cytoplasm.

• photosynthesis

• osmosis

• fermentation

• evapotranspiration

Answer explanation

The sequence of reactions that converts glucose into pyruvate with the production of a relatively small amount of ATP.

Glycolysis is the pathway utilized by yeast to produce the __________ found in beer.

• hops

• starch

• sugar

• alcohol

Answer explanation

Glycolysis can be carried out anaerobically (in the absence of oxygen) and is thus an especially important pathway for organisms that can ferment sugars.



However, it only produces 2 moles of ATP, which is a small amount compared to some other methods of energy production.

In the absence of oxygen, when yeast converts sugar into carbon dioxide and alcohol, this is known as __________.

• evapotranspiration

• hydrologic cycle

• fermentation

• photosynthesis

Answer explanation

Fermentation can also refer to any of a group of chemical reactions induced by living or nonliving ferments that split complex organic compounds into relatively simple substances.

__________ is destructive metabolism. Typically, larger organic molecules are broken down into smaller constituents.

• Exocytosis

• Endocytosis

• Anabolism

• Catabolism

Answer explanation

This usually occurs with the release of energy (usually as ATP). The opposite is anabolism.

In biochemical reactions, the gain of an electron is known as __________. If accompanied by H+ ions, this can be seen as a gain of H.

• reduction

• production

• induction

• conduction

Answer explanation

This is because adding an electron means adding a negative charge. If the compound previously had a +2 charge, it becomes +1 with the addition of an electron.



The opposite of reduction--i.e. the loss of an electron (or hydrogen) is known as oxidation.

Reactions with a coupled oxidation- reduction mechanism are called __________-reactions.

• glycolysis

• catabolic

• redox

• allosteric

Answer explanation

An oxidation-reduction (redox) reaction is one where one species loses electrons and another gains them. For example, the reaction

Cu⁺²(aq) + Zn(s) -> Zn⁺²(aq) + Cu(s)

is a redox reaction. The copper gains two electrons and the zinc loses two.

In all redox reactions, reduction and oxidation occur together: one cannot happen without the other. The electrons flow from one species to the other: there is no net charge gain or loss.

The species that causes another to be oxidized is called an oxidizing agent. It takes up the electrons that the oxidized species gives off and is therefore reduced. The reverse is true for a reducing (redox) agent. In the above reaction:

• Zn is the redox agent: it is oxidized

• Cu⁺² is the oxidizing agent: it is reduced

During __________, conversion of one mole of glucose to two moles of pyruvate is accompanied by the net production of two moles each of ATP and NADH.

• glycolysis

• oxidative

• catalytic

• metabolic

Answer explanation

This is formed from the coenzyme NAD (Nicotinamide adenine dinucleotide) which acts as a redox agent in glycolysis (C₆H₁₂O₆ + 2NAD+ -> 2C₃H₄O₃ + 2NADH + 2H+)

As you can see, adding in NAD, a redox agent, resulted in four hydrogen atoms separating from the glucose molecule (C₆H₁₂O₆). The glucose is oxidized, and the NAD is reduced.