4.5–4.11
4.5–Photosynthesis uses energy from sunlight to make food.

In photosynthesis, plants transform light energy into the chemical energy of ATP and NADPH, while splitting water molecules and producing oxygen.

173

Q

In your body, when energy is released during the breakdown of glucose:

  • a) adenosine monophosphate is created.
  • b) adenosine diphosphate is created.
  • c) some energy may be harnessed to build high-energy bonds that attach phosphate groups to ADP molecules.
  • d) molecules of ATP capture and absorb the heat from the reaction.
  • e) it forms adenosine-CoA.

A green plant can carry out photosynthesis if given nothing more than:

  • a) water, light, and carbon dioxide.
  • b) water, light, and oxygen.
  • c) carbon dioxide.
  • d) oxygen.
  • e) oxygen and carbon dioxide.

The actual production of sugars during photosynthesis takes place:

  • a) in the chloroplast outer membrane.
  • b) within the stroma, inside the thylakoids of the chloroplast.
  • c) within the stroma, outside the thylakoids of the chloroplast.
  • d) within the mitochondria.
  • e) within the thylakoid membranes.

The leaves of plants can be thought of as “eating” sunlight because:

  • a) light energy, like chemical energy released when the bonds of food molecules are broken, is a type of kinetic energy.
  • b) both light energy and food energy can be interconverted without heat loss.
  • c) the carbon-oxygen bonds within a photon of light release energy when broken by the enzymes in chloroplasts.
  • d) the carbon-hydrogen bonds within a photon of light release energy when broken by the enzymes in chloroplasts.
  • e) photons contain hydrocarbons.

A molecule of chlorophyll increases in potential energy:

  • a) when it binds to a photon.
  • b) when a photon strikes it, boosting electrons to a higher-energy excited state.
  • c) when it loses an electron.
  • d) only in the presence of oxygen.
  • e) None of the above. The potential energy of a molecule cannot change.

174