Name ______Hour ____
8.1Energy and Life
Chemical Energy and ATP
1.Energy is the ability to do work.
2.The main chemical compound cells use for energy is adenosine triphosphate (ATP).
3.Ribose is a 5-carbon sugar molecule that is part of an ATP molecule.
4.The phosphate groupof ATP are the key to its ability to store and supply energy.
5.ATP releases energy when it Phosphate group breaks bonds between its phosphate groups.
6.Most cells only store enough ATP for a few seconds of activity.
Heterotrophs and Autotrophs
For Questions 13–17, write True if the statement is true. If the statement is false, change the underlined word or words to make the statement true.
TRUE7.All heterotrophs must eat food to get energy.
TRUE8.Autotrophs do not need to eat food because they make food.
THE SUN9.The energy in food originally came from ATP.
Putting together10.The term photosynthesis means “pulling apart with light” in Greek.
TRUE11.The energy of sunlight is stored in the chemical bonds of carbohydrates.
12.Suppose that you ate a hamburger on a wheat roll with lettuce, tomatoes, and onions for lunch. As you ate, you took in food molecules from plants and animals. Explain why all the energy in the food molecules of this hamburger could be traced back to the sun.
SAMPLE ANSWER: The bread, lettuce, tomatoes, and onions in a hamburger all came fromplants. The food molecules in those plants were made as a result of the process ofphotosynthesis, using the energy in sunlight. The hamburger meat came from a cow,which ate grass and other plants to obtain food. The cow made the molecules in themeat by using the energy in the food molecules from the plants, which originally came from the sun.
8.2 Photosynthesis: An Overview
Chlorophyll and Chloroplasts
1. The wavelengthof light determines its color.
2. Chemicals that absorb light are called pigments.
3. Chlorophyll makes plants look green because it reflects green light.
An Overview of Photosynthesis
B 5. What are the reactants of the photosynthesis reaction?
A. chlorophyll and light C. carbohydrates and oxygen
B. carbon dioxide and water D. high-energy electrons and air
C 6. What are the products of the light-dependent reactions?
A. chloroplasts and light C. oxygen and ATP
B. proteins and lipids D. water and sugars
9.1 Cellular Respiration: An Overview
Chemical Energy and Food
1. A calorie is a unit of energy.
2. The Calorie used on food labels is equal to 1000calories.
3. A Calorie is also referred to as a kilocalorie.
4. Cells use the energy stored in chemical bonds of foods to produce compounds that directly power the cell’s activities, such as ATP.
Overview of Cellular Respiration
5. The equation that summarizes cellular respiration, using chemical formulas, is
______6O2 + C6H12O6 ➝6CO2 + 6H2O + Energy________.
6.The pathways of cellular respiration that require oxygen are said to be aerobic. Pathways that do not require oxygen are said to be anaerobic.
Comparing Photosynthesis and Cellular Respiration
Complete the table using the words below. Some words may be used more than once. You will use more than one term in some of the spaces.
Photosynthesis / Cellular RespirationFunction / energy capture / Energy release
Location / chloroplasts / Mitochondria
Reactants / Water & carbon dioxide / glucose and oxygen
Products / oxygen and glucose / Carbon dioxide & water
Answer the questions
7. Circle the correct answer. Which process releases energy for the cell?
cellular respirationphotosynthesis
8. Circle the correct answer. For which reaction is 6CO2 + 6H2O → C6H12O6 + 6O2 the correct equation?
cellular respirationphotosynthesis
9. Which statement about cellular respiration is true?
A. Cellular respiration does not use energy.
B. The total amount of energy is constant.
C. Energy is destroyed during the reaction.
D. Energy is created during the reaction.
10. How are the processes of photosynthesis and cellular respiration connected?
A. The products of both processes are the same.
B. The reactants for one process are the same as the reactants for the other process.
C. Each process provides the materials needed in the other process.
D. There is no direct relationship.
9.3 Fermentation
Term / DefinitionFermentation / The anaerobic process that releases energy from food molecules by producing ATP.
A Venn diagram is made up of overlapping circles. It is a useful tool for comparing two or even three topics. As you read about the two forms of fermentation in Lesson 3, complete the Venn diagram below.
Fermentation
Circle the correct answer. Questions may have more than one correct answer.
3. Alcoholic fermentation is used to make which product?
breadcheeseyogurtpickles
4. What kind of taste do lactic acid bacteria give foods?
sweetsaltysourspicy
5. What are some milk products made from lactic acid fermentation?
milksour creamyogurtcheese
6. What is one main difference between fermentation and aerobic respiration?
Sample answer: Fermentation is anaerobic, so it takes place without oxygen. Aerobicrespiration takes place with oxygen.
The two main types of fermentation are named for the products they form.
Lactic Acid Fermentation / Alcoholic FermentationReactants / pyruvic acid / pyruvic acid
End products / lactic acid / carbon dioxide and ethyl alcohol
Uses by humans / producing certain foods; producing
energy during exercise / to make bread