ISB 202 Appl Envir and Organismal Biology Chapter 5

How do chlorophyll pigments absorb energy from light?

A photon excites an electron in the chlorophyll to a higher energy state.

A) What provides the energy that excites the electrons in the chlorophyll molecules? B) What is the source of the electrons that replace the excited electrons lost from chlorophyll?

A) light B) H2O

What does the law of conservation of energy state?

Energy cannot be either created or destroyed, but it can be transformed.

Suppose that you conduct an experiment to determine how photosynthetic output, measured in oxygen (O2) production, changes as you alter photosynthesis, and generate the graph. Identify which manipulations to photosynthesis generated the observed changes in O2 production depicted in the graph.

Highest to Lowest: High CO2, High O2, green light, high temperature

Select all of the statements that accurately describe photorespiration.

Photorespiration reduces the net amount of O2 produced during photosynthesis; Photorespiration is metabolically expensive; Photorespiration reduces the rate at which sugar is produced by the Calvin cycle

Complete the photosynthesis reaction by placing the compounds and energy sources into the reaction as reactants or products. One molecule will not be placed.

Photosynthesis Reactants: carbon dioxide, water, light energy Photosynthesis Products: simple sugars, oxygen

Which of the statements regarding potential energy is true?

Potential energy is the energy that an object has based on its position.

Why does disrupting the Calvin cycle impact the light reactions of photosynthesis?

The Calvin cycle regenerates NADP+; The Calvin cycle regenerates ADP

What is the primary role of water in photosynthesis?

The breakdown of water provides electrons and H+ ions for the light reactions.

Which statement describes the function of photosynthetic pigments in leaves?

They capture light energy and remove electrons from a donor.

Which substances are produced during photosynthesis in plants?

oxygen; carbohydrates

Which of the statements describe photosynthesis?

is a cellular process that occurs in the chloroplasts of plant cells; converts carbon dioxide to sugars, releasing oxygen; produces sugars for the plant using the energy from sunlight

Choose the best description of kinetic energy.

the energy an object has as a result of its own movement

Which of the statements describes heat?

the transfer of thermal energy from one body to another

Which molecules are reactants in photosynthesis in plants?

water; carbon dioxide