Food as a Source of Energy - Practical 7.8
56 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does a high energy value on a food label indicate?

  • The food is primarily made of carbohydrates
  • The food provides a lot of energy per serving (correct)
  • The food is unsuitable for a diet
  • The food has low nutritional value
  • How is the energy value of food commonly measured?

  • Volume in milliliters
  • Liters per serving
  • Grams of fat
  • Calories or kilojoules (correct)
  • What is the relationship between kilocalories and kilojoules?

  • 1 kcal is half of a kJ
  • 1 kJ is equivalent to 0.25 kcal
  • 1 kcal is equivalent to 4.2 kJ (correct)
  • 1 kcal is equivalent to 2.5 kJ
  • What can be inferred when food is burnt regarding energy?

    <p>Energy is released in a substantial amount (C)</p> Signup and view all the answers

    What does examining nutrition labels help in understanding?

    <p>The energy values of different foods (B)</p> Signup and view all the answers

    What is the primary purpose of food in living organisms?

    <p>To serve as a source of energy (C)</p> Signup and view all the answers

    During which bodily activities is energy from food utilized?

    <p>Throughout all bodily functions, including at rest (B)</p> Signup and view all the answers

    What could happen if the boiling tube is clamped too tightly during the practical?

    <p>The boiling tube may break (C)</p> Signup and view all the answers

    Which apparatus is necessary to measure the temperature of water in the boiling tube?

    <p>Alcohol thermometer (D)</p> Signup and view all the answers

    Which safety precaution should be considered when using the boiling tube?

    <p>Do not clamp too loosely (D)</p> Signup and view all the answers

    What might be observed about energy release from food during the experiment?

    <p>It can be measured with temperature change (C)</p> Signup and view all the answers

    What should be avoided when heating the boiling tube?

    <p>Allowing the thermometer bulb to touch the boiling tube. (B), Heating the boiling tube directly with a Bunsen flame. (C)</p> Signup and view all the answers

    What is the primary purpose of respiration in living organisms?

    <p>To release energy from food (D)</p> Signup and view all the answers

    In the context of energy extraction, what process is implied when stating energy is obtained from food?

    <p>Respiration (B)</p> Signup and view all the answers

    Which of the following substances is generally required for respiration?

    <p>Oxygen (B)</p> Signup and view all the answers

    What are the typical byproducts of the respiration process?

    <p>Carbon dioxide and water (D)</p> Signup and view all the answers

    Where does respiration primarily take place within living organisms?

    <p>In the mitochondria of cells (A)</p> Signup and view all the answers

    Which equation best summarizes the process of respiration?

    <p>Oxygen + Glucose → Water + Energy (A)</p> Signup and view all the answers

    Which statement about respiration is true?

    <p>It is a catabolic process (D)</p> Signup and view all the answers

    Which of the following is NOT a function of the energy released during respiration?

    <p>Synthesizing carbohydrates (A)</p> Signup and view all the answers

    What is the role of carbon dioxide in photosynthesis in plants?

    <p>It is used to make food. (C)</p> Signup and view all the answers

    What is expected to happen to the carbon dioxide content in a boiling tube with green leaves in the dark?

    <p>It will increase significantly. (C)</p> Signup and view all the answers

    During respiration, what gas do green plants take in and what gas do they release?

    <p>Carbon dioxide in and oxygen out. (A)</p> Signup and view all the answers

    What color change would you expect in the hydrogencarbonate indicator if carbon dioxide levels rise?

    <p>From red to yellow. (C)</p> Signup and view all the answers

    Which of the following would NOT be an expected result of the practical involving gas exchange in plants?

    <p>Carbon dioxide levels remaining constant in the dark. (C)</p> Signup and view all the answers

    Which factor is critical for ensuring air does not leak from the tubes?

    <p>The tightness of the stoppers (B)</p> Signup and view all the answers

    What effect does wrapping tubes C and D with aluminum foil have?

    <p>It prevents photosynthesis from occurring in those tubes (D)</p> Signup and view all the answers

    What is the main purpose of repositioning the leaves within the tubes?

    <p>To allow for proper gas exchange (D)</p> Signup and view all the answers

    What happens to carbon dioxide levels in plants under light conditions?

    <p>There is a net uptake of carbon dioxide. (A)</p> Signup and view all the answers

    In the absence of light, what occurs in plants?

    <p>Only respiration takes place. (B)</p> Signup and view all the answers

    Which statement best describes gas exchange in plants during light conditions?

    <p>Plants take in carbon dioxide and release oxygen. (A)</p> Signup and view all the answers

    How do plants fare in terms of oxygen production during the day?

    <p>They produce more oxygen than they consume. (D)</p> Signup and view all the answers

    Under which conditions will plants have a net uptake of oxygen?

    <p>During light conditions only. (A)</p> Signup and view all the answers

    What primarily determines the net gas exchange in plants?

    <p>The balance between photosynthesis and respiration. (B)</p> Signup and view all the answers

    What is the effect of dark conditions on the process of photosynthesis?

    <p>Photosynthesis stops completely. (D)</p> Signup and view all the answers

    What occurs in plants under light conditions concerning gas exchange?

    <p>There is a net uptake of carbon dioxide and release of oxygen. (C)</p> Signup and view all the answers

    What is the role of stomata in plants?

    <p>To allow gases to move in and out of leaves. (D)</p> Signup and view all the answers

    What is the net gas exchange effect in plants under dark conditions?

    <p>Net release of carbon dioxide and net uptake of oxygen. (B)</p> Signup and view all the answers

    Which process occurs continuously in green plants regardless of light conditions?

    <p>Respiration only. (D)</p> Signup and view all the answers

    How does the net gas exchange in plants vary?

    <p>It depends on the relative rates of photosynthesis and respiration. (B)</p> Signup and view all the answers

    During which of the following conditions does photosynthesis not occur?

    <p>Complete darkness. (C)</p> Signup and view all the answers

    Which statement about gas release and uptake in plants is true when comparing light and dark conditions?

    <p>Photosynthesis dominates in light and respiration dominates in the dark. (D)</p> Signup and view all the answers

    What misconception do many people have regarding respiration in green plants?

    <p>Respiration does not occur in the presence of light. (C)</p> Signup and view all the answers

    What is the main function of stomata in plants?

    <p>To facilitate gas exchange (C)</p> Signup and view all the answers

    What occurs during gas exchange in plants when the rate of photosynthesis exceeds the rate of respiration?

    <p>Net release of oxygen (A), Net uptake of carbon dioxide (C)</p> Signup and view all the answers

    What are the two main gases exchanged through the stomata during photosynthesis and respiration?

    <p>Oxygen and carbon dioxide (C)</p> Signup and view all the answers

    Under dark conditions, what is the primary gas exchange activity in plants?

    <p>Respiration only (D)</p> Signup and view all the answers

    What is a key factor that determines the net gas exchange in plants?

    <p>The relative rates of photosynthesis and respiration (C)</p> Signup and view all the answers

    Which structure is primarily responsible for gas exchange in plants?

    <p>Stoma (C)</p> Signup and view all the answers

    When preparing a biological drawing of a stoma, which factor is essential to maintain?

    <p>Proportional size of different parts (C)</p> Signup and view all the answers

    What would result from the respiration rate being higher than the rate of photosynthesis in a plant?

    <p>Net release of carbon dioxide (A)</p> Signup and view all the answers

    What is the net gas exchange at a potted plant's leaves on a warm sunny day at noon?

    <p>Net uptake of carbon dioxide and net release of oxygen (C)</p> Signup and view all the answers

    Which condition correctly represents the gas exchange dynamics in a plant that is solely in dark conditions?

    <p>High net release of carbon dioxide and uptake of oxygen (C)</p> Signup and view all the answers

    Which of the following is NOT true about stomata?

    <p>They only exist on the underside of leaves (B)</p> Signup and view all the answers

    During light conditions, what is the net effect of gas exchange in plants?

    <p>Net uptake of carbon dioxide and release of oxygen (D)</p> Signup and view all the answers

    What happens if a plant's rate of respiration significantly increases beyond the photosynthesis rate?

    <p>Increased carbon dioxide release (B)</p> Signup and view all the answers

    Flashcards

    Food as Energy Source

    Food provides the energy needed for body functions like movement, reading, and thinking, even when resting.

    Energy Release in Food

    The energy stored in food is released and transformed into other energy forms for bodily activities.

    Practical 7.8

    A lab experiment designed to observe energy release from food.

    Boiling Tube

    A glass tube used to hold water in the experiment.

    Signup and view all the flashcards

    Alcohol Thermometer

    Measures temperature changes in the water.

    Signup and view all the flashcards

    Bunsen Burner

    A heat source used in the experiment.

    Signup and view all the flashcards

    Safety Precautions

    Important steps to take to prevent accidents during the experiment, like avoiding clamping the tube too tightly.

    Signup and view all the flashcards

    Energy from Peanuts

    The experiment investigates the energy produced when peanuts are burned to release energy

    Signup and view all the flashcards

    Energy value of food

    The amount of energy a food provides.

    Signup and view all the flashcards

    Kilocalorie (kcal)

    A unit of energy, often used to measure the energy value of food.

    Signup and view all the flashcards

    Energy released when food is burnt

    Energy is released, either in a controlled or uncontrolled situation.

    Signup and view all the flashcards

    Nutrition labels

    Labels on food packages that provide information about the food's nutritional value, including energy value.

    Signup and view all the flashcards

    Energy value units

    Kilocalories or kilojoules, often on nutrition labels, indicate energy values of foods.

    Signup and view all the flashcards

    Heat peanut

    Burning a peanut in a spoon over a Bunsen burner to heat the water in the boiling tube.

    Signup and view all the flashcards

    Initial water temperature

    The temperature of water in the boiling tube before heating.

    Signup and view all the flashcards

    Final water temperature

    The temperature of water in the boiling tube after heating the burnt peanut.

    Signup and view all the flashcards

    Burning spoon

    Spoon used to hold and heat the burning peanut.

    Signup and view all the flashcards

    Thermometer placement

    The bulb of the thermometer should not touch the bottom of the boiling tube.

    Signup and view all the flashcards

    Safety spectacles

    Protective eyewear to wear during the experiment.

    Signup and view all the flashcards

    Insulating mat

    A surface to place the burning spoon on to contain heat.

    Signup and view all the flashcards

    Respiration

    The process where living organisms break down food to release energy.

    Signup and view all the flashcards

    Energy from Food

    Food contains stored energy that can be released through respiration, providing energy for bodily functions.

    Signup and view all the flashcards

    What is the purpose of respiration?

    To release energy stored in food for bodily processes like movement, growth, and thinking.

    Signup and view all the flashcards

    Serving Size

    The amount of food considered in a single serving, usually specified in grams or milliliters.

    Signup and view all the flashcards

    Protein

    A nutrient essential for building and repairing tissues, making enzymes, and other vital functions.

    Signup and view all the flashcards

    Total Fat

    The total amount of fat in a food, including saturated and unsaturated fats.

    Signup and view all the flashcards

    Saturated Fat

    A type of fat typically found in animal products and some plants, which is linked to heart health concerns if consumed in excess.

    Signup and view all the flashcards

    Trans Fat

    An unhealthy type of fat created during food processing, which can raise cholesterol levels.

    Signup and view all the flashcards

    Cholesterol

    A waxy substance found naturally in the body and in certain foods, which plays a role in various bodily functions.

    Signup and view all the flashcards

    Carbohydrates

    A major source of energy for the body, found in foods like bread, pasta, and fruit.

    Signup and view all the flashcards

    Nutritional Information

    Information on the content of a food, typically found on the product label, including calories, proteins, fats, carbohydrates, and vitamins.

    Signup and view all the flashcards

    Glucose

    A type of sugar that is the main source of energy for most living things.

    Signup and view all the flashcards

    Energy Conversion

    The process of changing energy from one form to another. During respiration, chemical energy in food is converted to useful forms of energy.

    Signup and view all the flashcards

    Oxygen's Role in Respiration

    Oxygen is usually needed during respiration. It acts as an electron acceptor, helping to break down glucose and release energy.

    Signup and view all the flashcards

    Carbon Dioxide & Water as Products

    Carbon dioxide and water are the waste products of respiration.

    Signup and view all the flashcards

    Chemical Reactions in Respiration

    Respiration involves a series of controlled chemical reactions that release energy from food.

    Signup and view all the flashcards

    Controlled Chemical Reactions

    The chemical reactions in respiration are carefully controlled to prevent a sudden release of all energy.

    Signup and view all the flashcards

    Summary Equation for Respiration

    A simplified equation that shows the overall process of respiration: Glucose + Oxygen → Carbon Dioxide + Water + Energy

    Signup and view all the flashcards

    Photosynthesis

    The process plants use to make their own food using sunlight, carbon dioxide, and water.

    Signup and view all the flashcards

    Gas Exchange in Plants

    The process of plants taking in carbon dioxide and releasing oxygen during photosynthesis, and taking in oxygen and releasing carbon dioxide during respiration.

    Signup and view all the flashcards

    What do plants take in during photosynthesis?

    Plants take in carbon dioxide and water during photosynthesis.

    Signup and view all the flashcards

    What do plants release during photosynthesis?

    Plants release oxygen during photosynthesis.

    Signup and view all the flashcards

    What do plants take in during respiration?

    Plants take in oxygen during respiration.

    Signup and view all the flashcards

    What do plants release during respiration?

    Plants release carbon dioxide and water during respiration.

    Signup and view all the flashcards

    Hydrogencarbonate Indicator

    A solution that changes color based on the amount of carbon dioxide present. Red means low carbon dioxide, yellow means high carbon dioxide, and purple means normal levels.

    Signup and view all the flashcards

    Net Gas Exchange

    The overall exchange of gases in plants, taking into account both photosynthesis and respiration.

    Signup and view all the flashcards

    Net Uptake

    When a plant takes in more of a gas than it releases.

    Signup and view all the flashcards

    Net Release

    When a plant releases more of a gas than it takes in.

    Signup and view all the flashcards

    Gas Exchange under Light Conditions

    Plants take in carbon dioxide and release oxygen because photosynthesis is faster than respiration.

    Signup and view all the flashcards

    Gas Exchange under Dark Conditions

    Plants take in oxygen and release carbon dioxide because respiration is the only process happening.

    Signup and view all the flashcards

    Stomata

    Tiny pores on plant leaves that allow gases to pass in and out.

    Signup and view all the flashcards

    What is the role of stomata?

    Stomata allow carbon dioxide, oxygen, and water vapor to move in and out of the plant.

    Signup and view all the flashcards

    How do stomata open and close?

    Stomata open and close based on factors like light intensity, carbon dioxide concentration, and water availability.

    Signup and view all the flashcards

    Leaf Epidermis

    The outer layer of cells on a leaf, where stomata are found.

    Signup and view all the flashcards

    Prepared Slide

    A slide containing a thin section of a leaf epidermis, ready for viewing under a microscope.

    Signup and view all the flashcards

    Magnification

    The ability of a microscope to enlarge an object's image.

    Signup and view all the flashcards

    Biological Drawing

    A detailed and accurate drawing of a specimen observed under a microscope.

    Signup and view all the flashcards

    Labelled Diagram

    A diagram showing the different parts of a specimen and labeled with their names.

    Signup and view all the flashcards

    Misconception: Photosynthesis occurs only in light, and respiration only in dark.

    Photosynthesis and respiration occur simultaneously in plants, with the rate of each process depending on conditions.

    Signup and view all the flashcards

    Key Point: Net gas exchange depends on photosynthesis and respiration rates.

    The overall gas exchange in plants is determined by which process is faster: photosynthesis or respiration.

    Signup and view all the flashcards

    True or False: Plants do not need to take in oxygen from the atmosphere.

    False, plants need oxygen for respiration to release energy from food.

    Signup and view all the flashcards

    True or False: When respiration is faster than photosynthesis, there is a net release of carbon dioxide.

    True, when respiration is faster, plants release more CO2 than they take in.

    Signup and view all the flashcards

    Net Uptake and Release of Gases in Sunlight

    In sunlight, plants have a net uptake of carbon dioxide and a net release of oxygen, due to photosynthesis being faster than respiration.

    Signup and view all the flashcards

    Structure for Gas Exchange in Plants

    Stomata are the primary structures for gas exchange in plants.

    Signup and view all the flashcards

    Gas Exchange in Sunlight

    Plants have a net uptake of carbon dioxide and a net release of oxygen because photosynthesis is faster than respiration.

    Signup and view all the flashcards

    Gas Exchange in Darkness

    Plants have a net uptake of oxygen and a net release of carbon dioxide because respiration is the only process happening.

    Signup and view all the flashcards

    Photosynthesis Rate

    The speed at which plants convert sunlight, carbon dioxide, and water into food.

    Signup and view all the flashcards

    Respiration Rate

    The speed at which plants break down food to release energy.

    Signup and view all the flashcards

    Net Uptake of Carbon Dioxide

    When a plant takes in more carbon dioxide than it releases.

    Signup and view all the flashcards

    Net Release of Oxygen

    When a plant releases more oxygen than it takes in.

    Signup and view all the flashcards

    Gas Exchange Under Light

    Plants take in carbon dioxide and release oxygen because photosynthesis is faster than respiration.

    Signup and view all the flashcards

    Gas Exchange Under Darkness

    Plants take in oxygen and release carbon dioxide because respiration is the only process happening.

    Signup and view all the flashcards

    Photosynthesis vs. Respiration

    Photosynthesis uses sunlight to make food (glucose) and release oxygen, while respiration breaks down glucose to release energy and carbon dioxide. Both happen simultaneously in plants.

    Signup and view all the flashcards

    Light and Dark Conditions

    In light, photosynthesis is faster, resulting in a net uptake of carbon dioxide and release of oxygen. In dark, respiration is the only process, leading to a net release of carbon dioxide and uptake of oxygen.

    Signup and view all the flashcards

    What is the purpose of tubes B and D?

    Tubes B and D serve as control groups. They ensure that any changes observed in tubes A and C are due to the presence of green leaves, not other factors like light or temperature.

    Signup and view all the flashcards

    Compare tubes A and B. What does it tell us about leaves?

    Tube A, with green leaves, turns purple, indicating a decrease in carbon dioxide. Tube B, without leaves, stays red, suggesting no change in carbon dioxide. This shows that green leaves under light conditions take in carbon dioxide.

    Signup and view all the flashcards

    What is the purpose of wrapping tubes C and D in foil?

    Aluminum foil blocks light. Tubes C and D are control groups to see if the presence of light is necessary for any color changes in the indicator.

    Signup and view all the flashcards

    Compare tubes C and D. What does it tell us about leaves?

    The indicator in tube C, with green leaves and no light, remains red, while tube D, without leaves and no light, also stays red. This indicates that leaves don't take in carbon dioxide in the dark.

    Signup and view all the flashcards

    What do plants do under light conditions?

    In the light, leaves take in carbon dioxide and release oxygen. This process is called photosynthesis, where plants use sunlight to make their own food.

    Signup and view all the flashcards

    What do plants do in the dark?

    In the dark, leaves take in oxygen and release carbon dioxide. This process is called respiration, where plants break down food for energy.

    Signup and view all the flashcards

    What is the takeaway?

    This experiment shows that green leaves take in carbon dioxide under light conditions, demonstrating that photosynthesis is happening. In darkness, leaves don't take in carbon dioxide, showing that respiration is slower than photosynthesis in the light.

    Signup and view all the flashcards

    What is gas exchange?

    The process where plants take in carbon dioxide and release oxygen for photosynthesis, and take in oxygen and release carbon dioxide for respiration.

    Signup and view all the flashcards

    How do plants exchange gases?

    Through tiny pores called stomata on their leaves.

    Signup and view all the flashcards

    What affects net gas exchange in plants?

    The relative rates of photosynthesis and respiration.

    Signup and view all the flashcards

    Net gas exchange in sunlight

    Plants have a net uptake of carbon dioxide and a net release of oxygen because photosynthesis is faster.

    Signup and view all the flashcards

    Net gas exchange in darkness

    Plants have a net uptake of oxygen and a net release of carbon dioxide because respiration is the only process happening.

    Signup and view all the flashcards

    What is the purpose of respiration in plants?

    To break down food and release energy for growth and other processes.

    Signup and view all the flashcards

    What is the purpose of photosynthesis in plants?

    To make their own food using sunlight, carbon dioxide, and water.

    Signup and view all the flashcards

    Photosynthesis in Plants

    The process by which plants use sunlight, carbon dioxide, and water to make their own food (glucose) and release oxygen.

    Signup and view all the flashcards

    Respiration in Plants

    The process by which plants break down glucose to release energy for growth, repair, and other life processes, using oxygen and releasing carbon dioxide and water.

    Signup and view all the flashcards

    Gas Exchange in Dark

    Plants take in oxygen and release carbon dioxide because respiration is the only process happening.

    Signup and view all the flashcards

    Study Notes

    Food as a Source of Energy

    • Food provides energy for body activities like running, reading, and working, even when sleeping, for breathing and heart function
    • In living organisms, energy from food is released and converted into other forms of energy supporting body functions
    • Practical 7.8 demonstrates energy release from food

    Burning Food Practical (Practical 7.8)

    • Aim: To study energy release from food
    • Materials (per group): Boiling tube, alcohol thermometer, burning spoon, Bunsen burner, insulating mat, stand and clamp, two-holed stopper, gas lighter, peanut
    • Procedure:
      • Fill a boiling tube with water (⅓ full)
      • Insert an alcohol thermometer into the two-holed stopper, which is placed in the tube
      • Secure the boiling tube on a stand using a clamp
      • Record the initial water temperature (T₁)
      • Heat the peanut on a burning spoon over a Bunsen burner until it burns completely
      • Move the burning spoon around in the boiling tube
      • Record the final water temperature (T₂)
    • Caution: Do not clamp the boiling tube too tightly, do not let the thermometer bulb touch the bottom of the tube

    Respiration

    • Respiration is the process of releasing energy from food gradually inside cells.
    • Chemical energy in food (glucose) is converted to other usable forms of energy supporting body functions.
    • Oxygen is often needed during respiration.
    • Carbon dioxide and water are usually produced during respiration.
    • Respiration involves a series of controlled chemical reactions.

    Photosynthesis and Respiration

    • Photosynthesis converts carbon dioxide and water into food using light energy.
    • Respiration converts food back into carbon dioxide and water releasing energy.

    Energy Value of Food

    • The energy value of food represents the amount of energy contained in a specific quantity of food, measured in kilocalories (kcal) or kilojoules (kJ).
    • Nutrition labels on pre-packaged foods display energy values.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz explores the role of food as a source of energy and includes a practical experiment to study energy release from food using a peanut. You'll learn about the mechanisms where energy is stored in food and how it's converted for bodily functions. Engage with hands-on learning through the burning food practical.

    More Like This

    Cell &amp; Molecular Exam 2
    138 questions

    Cell &amp; Molecular Exam 2

    CongenialChupacabra avatar
    CongenialChupacabra
    Fuel Energy Release and Kinetic Energy Quiz
    25 questions
    Seismic Energy Release Technique
    4 questions

    Seismic Energy Release Technique

    UserReplaceableMolybdenum avatar
    UserReplaceableMolybdenum
    Use Quizgecko on...
    Browser
    Browser