PDF Skills Worksheet Active Reading - Biology - Home

Back Print

Name

Class

Date

Skills Worksheet

Active Reading

Section: Energy and Living Things

Read the passage below. Then answer the questions that follow.

The process by which light energy is converted to chemical energy is called photosynthesis. Organisms that use energy from sunlight or inorganic substances to make organic compounds are called autotrophs. Most autotrophs, especially plants, are photosynthetic organisms. Some autotrophs, including certain bacteria, use inorganic substances to make organic compounds.

Organisms that must get energy from food instead of directly from sunlight or inorganic substances are called heterotrophs. Heterotrophs, including humans and other animals, get energy from food through the process of cellular respiration.

SKILL: READING EFFECTIVELY

Read each question, and write your answer in the space provided.

1. The prefix photo- means "light." The root word synthesis comes from a Greek word that means "putting together." How could knowledge of these word parts help you define the word photosynthesis?

2. The prefix auto- means "self." The root word troph comes from a Greek word that means "to feed." How could knowledge of these word parts help you define the word autotroph?

3. The prefix hetero- comes from a Greek word that means "other." How could knowledge of this prefix and the root word troph help you define the word heterotroph?

Copyright ? by Holt, Rinehart and Winston. All rights reserved.

Holt Biology

7

Photosynthesis and Cellular Respiration

Back

Print

Name

Class

Date

Active Reading continued

4. Heterotrophs are to humans as autotrophs are to plants. What relationship forms the basis of this analogy?

5. How does cellular respiration help your body perform its life functions?

In the space provided, write the letter of the phrase that best answers the question.

______ 6. Which of the following most closely resembles cellular respiration? a. warm water moving through copper pipes b. people moving along an escalator c. mixing different foods in a blender d. logs burning in a campfire

Copyright ? by Holt, Rinehart and Winston. All rights reserved.

Holt Biology

8

Photosynthesis and Cellular Respiration

Back

PTErAinCHt ER RESOURCE PAGE

Answer Key

Directed Reading

SECTION: ENERGY AND LIVING THINGS 1. b 2. c 3. d 4. e 5. a 6. 5

7. 2 8. 4 9. 1 10. 3 11. During cellular respiration, stored

chemical energy is released gradually in a series of enzyme-assisted reactions. When a log is burned, stored chemical energy is released quickly as heat and light. 12. ATP is called an energy currency because cells can "spend it" in order to carry out cellular processes that require energy. 13. Energy is released from an ATP molecule when a phosphate group is removed from the molecule, forming an ADP molecule. 14. Many of the chemical reactions of metabolism require energy. The breakdown of ATP into ADP and phosphate groups releases energy in a way that cells can use it for metabolism.

SECTION: PHOTOSYNTHESIS 1. 3 2. 1 3. 2 4. Almost all of the energy we use comes

from plants, which get their energy directly from sunlight. 5. 3CO2 + 3H2O C3H6O3 3O2 6. pigments 7. carotenoids 8. water 9. NADPH 10. electron transport 11. phosphate

12. The Calvin cycle uses carbon dioxide from the air, energy from ATP, and electrons from NADPH to produce organic compounds. Some of the three-carbon sugar molecules made by the Calvin cycle are used to make other substances needed for energy and growth. The other three-carbon sugar molecules are used to regenerate the five-carbon starting compound and continue the cycle.

13. light intensity, carbon dioxide concentration, and temperature

SECTION: CELLULAR RESPIRATION 1. cellular respiration 2. aerobic 3. glycolysis 4. glucose 5. pyruvate 6. Pyruvate produced during glycolysis

enters a mitochondrion and breaks down into a carbon dioxide molecule and a two-carbon acetyl group. The acetyl group attaches to a coenzyme A molecule, forming acetyl-CoA. 7. water and a large amount of ATP 8. electron transport chain 9. alcoholic, lactic acid 10. NAD 11. When muscle cells do not get enough oxygen, pyruvate is converted to lactate, which can build up in the muscle cells and cause soreness. 12. The electron transport chain, which produces a large amount of ATP, operates under aerobic conditions but not under anaerobic conditions.

Active Reading

SECTION: ENERGY AND LIVING THINGS 1. a putting together of substances,

including substances found in light energy, to form chemical energy 2. capable of producing organic compounds, or food, from within itself

Copyright ? by Holt, Rinehart and Winston. All rights reserved.

Holt Biology

77

Photosynthesis and Cellular Respiration

Back

PTErAinCHt ER RESOURCE PAGE

3. A heterotroph must obtain organic compounds, or food, by consuming another organism.

4. The analogy identifies a classification group and a specific member of that group.

5. Through cellular respiration, the human body gets energy from food. This energy is needed for an organism to carry out its life processes.

6. d

SECTION: PHOTOSYNTHESIS 1. Photosynthesis is directly affected by

various environmental factors. 2. A decrease in light intensity would

cause a similar decrease in the photosynthesis level of the plant. 3. Once the light saturation point is reached, light intensity has minimal effect on the photosynthesis level of a plant. 4. The concentration of carbon dioxide steadily increased during the study, causing an increased rate of photosynthesis. At the point when the rate leveled off, the carbon dioxide concentration had reached its maximum point. 5. Air temperature dropped to a point at which plant enzymes involved in photosynthesis could not operate efficiently. 6. b

SECTION: CELLULAR RESPIRATION 1. Glycolysis occurs in the cytosol of a

cell. 2. Glycolysis is not dependent upon the

presence of oxygen. 3. It is broken down to form two three-

carbon molecules of pyruvate. 4. The energy comes from stored energy

in the glucose molecule. 5. d

Vocabulary Review

1. photosynthesis 2. autotrophs 3. heterotrophs 4. cellular respiration 5. pigment 6. chlorophyll 7. carotenoids 8. electron transport chain 9. carbon dioxide fixation 10. Calvin cycle 11. aerobic 12. anaerobic 13. glycolysis 14. Krebs cycle 15. fermentation 16. thylakoids

Science Skills

1. food chain A: corn--10,000 kcal; human vegetarians--1,000 kcal; food chain B: corn--10,000 kcal; cattle-- 1,000 kcal; human meat eaters-- 100 kcal

2. Because 90 percent of the energy from one trophic level never makes it to the next level, there is rarely enough energy available to sustain a fifth level.

3. Some energy is lost as heat, and some is used up in cellular respiration.

4. Activity increases the required kcal/hour by about 62 percent. Plant foods would be a more efficient diet; a vegetarian diet provides 10 times as much energy as a meat diet.

5. Because humans have access to 10 times as much energy when their diet consists of grains, such as wheat, rice, and corn, rather than meat, eating foods that are lowest on the food chain makes sense.

Concept Mapping

1. glucose 2. glycolysis 3. anaerobic process 4. fermentation 5. NAD 6. pyruvate 7. Krebs cycle 8. electron transport chain

Copyright ? by Holt, Rinehart and Winston. All rights reserved.

Holt Biology

78

Photosynthesis and Cellular Respiration

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download