Activity 9 Homework Answer Key
Activity 9.1 A Quick Review of Energy Transformations
Review Chapter 8 and pages 160–162 of Chapter 9 in Biology, 7th edition. Then complete the discussion by supplying or choosing the appropriate terms.
To maintain life, organisms must be able to convert energy from one form to another. For example, in the process of photosynthesis, algae, plants, and photosynthetic prokaryotes use the energy from sunlight to convert carbon dioxide and water to glucose and oxygen (a waste product).
The summary reaction for photosynthesis can be written as
6 CO2 6 H2O C6H12O6 6 O2
This type of reaction is an oxidation-reduction (or redox) reaction. This reaction is also [anabolic/catabolic] and [endergonic/exergonic].
In redox reactions, electrons (and associated H ions) are transferred from one compound or element to another. If one compound or element loses electrons and becomes oxidized, another must gain electrons and become reduced. For example, in photosynthesis, water becomes [oxidized/reduced] (to O2) and the electrons
(and associated H ions) it “loses” in the process [oxidize/reduce] CO2 to glucose.
[Anabolic/Catabolic] reactions “build” more complex molecules from simpler ones. To do this they require energy input. Reactions that require the input of energy are termed [endergonic/exergonic] reactions.
The reactions involved in aerobic respiration are also redox reactions:
C6H12O6 6 O2 6 CO2 6 H2O
In this set of reactions, however, more complex molecules are “broken down” into simpler ones. Glucose is broken down or becomes [oxidized/reduced] (to CO2), and the oxygen becomes [oxidized/reduced] (to water).
[Anabolic/Catabolic] reactions break down more complex molecules into simpler ones and in the process release energy. Reactions that release energy that can be used to do work are [endergonic/exergonic]. Therefore, aerobic respiration is a(n) [anabolic/catabolic] process and is [endergonic/exergonic].
Review Chapter 8 and pages 160–162 of Chapter 9 in Biology, 7th edition. Then complete the discussion by supplying or choosing the appropriate terms.
To maintain life, organisms must be able to convert energy from one form to another. For example, in the process of photosynthesis, algae, plants, and photosynthetic prokaryotes use the energy from sunlight to convert carbon dioxide and water to glucose and oxygen (a waste product).
The summary reaction for photosynthesis can be written as
6 CO2 6 H2O C6H12O6 6 O2
This type of reaction is an oxidation-reduction (or redox) reaction. This reaction is also [anabolic/catabolic] and [endergonic/exergonic].
In redox reactions, electrons (and associated H ions) are transferred from one compound or element to another. If one compound or element loses electrons and becomes oxidized, another must gain electrons and become reduced. For example, in photosynthesis, water becomes [oxidized/reduced] (to O2) and the electrons
(and associated H ions) it “loses” in the process [oxidize/reduce] CO2 to glucose.
[Anabolic/Catabolic] reactions “build” more complex molecules from simpler ones. To do this they require energy input. Reactions that require the input of energy are termed [endergonic/exergonic] reactions.
The reactions involved in aerobic respiration are also redox reactions:
C6H12O6 6 O2 6 CO2 6 H2O
In this set of reactions, however, more complex molecules are “broken down” into simpler ones. Glucose is broken down or becomes [oxidized/reduced] (to CO2), and the oxygen becomes [oxidized/reduced] (to water).
[Anabolic/Catabolic] reactions break down more complex molecules into simpler ones and in the process release energy. Reactions that release energy that can be used to do work are [endergonic/exergonic]. Therefore, aerobic respiration is a(n) [anabolic/catabolic] process and is [endergonic/exergonic].