Question

burning is a redox reaction that oxidizes c - c and c - h bonds into c = o and o - h bonds. sucrose and other sugars in this marshmallow are reacting with oxygen and producing carbon dioxide and water. due the drop in potential energy of the electrons in the products versus the reactants, energy is given off as heat and light. this is an example of an energy transformation. in the case of burning, chemical energy — meaning the potential energy of electrons in chemical bonds — is transformed to heat and light energy.
burning is a redox reaction that is uncontrolled and happens in one giant step. the redox reactions that occur during cellular respiration, in contrast, occur in many small, tightly controlled steps. in addition, they result in a very different energy transformation. instead of transforming chemical energy to heat and light energy, they transform chemical energy to electrical energy. the electrical energy exists in the form of electrical currents—flows of charge. this electrical energy is then used to drive molecular motors that use mechanical energy to produce atp.
so as you learn more about cellular respiration, ask yourself whether the step you are analyzing involves an energy transfer — in a redox reaction — or an energy transformation. is energy being transferred from one chemical bond to another or being transformed to electrical or mechanical energy?
which scenarios are an example of an energy transformation in cells? select all that apply.
when the sodium - potassium pump is phosphorylated, it changes shape in a way that allows it to move sodium and potassium ions across a membrane against a concentration and electrical gradient.
when the phosphate groups on atp are added to kinesin, kinesin changes shape to take a step down a microtubule.
during a chemical reaction, a phosphate group on a small molecule gets transferred to adp, producing atp.

Explanation:

Energy transformation in cells involves changing one form of energy to another (e.g., chemical to mechanical). The first two options show chemical energy (from ATP) being transformed to mechanical energy (movement of ions or kinesin). The third option is energy transfer (phosphate group transfer), not transformation.

Answer:

• When the sodium - potassium pump is phosphorylated, it changes shape in a way that allows it to move sodium and potassium ions across a membrane against a concentration and electrical gradient.
• When the phosphate groups on ATP are added to kinesin, kinesin changes shape to take a step down a microtubule.