Energy from FoodChap 7

How are autotrophs and heterotrophs different? Give an example of each.

PRODUCERS - PHOTOAUTOTROPHS

PRODUCERS - CHEMOAUTOTROPHS

CONSUMERS - HETEROTROPHS

Concept 7.1 – Sunlight powers life. Describe how organisms release energy from food.

Through cellular respiration, oxygen is used to release energy from glucose and produce

ATP.

What are some types of energy? Potential

Kinetic

Chemical

Concept 7.2 – Food stores chemical energy.3. What is the difference between kinetic energy and potential

energy?

Kinetic energy is the energy of motion.

Potential energy is energy that is stored.

Concept 7.2 – Food stores chemical energy.4. How do cells release chemical energy from food?

In cellular respiration, oxygen reacts with the organic molecules of food (sugar), breaking the molecules into smaller molecules and releasing chemical energy (ATP).

What are some activities that use energy?

Energy Consumed by Daily Activities

What is ATP?

Adenosine triphosphate. Is a nitrogencontaining compound called adenine and a five carbon sugar called ribose. Has three phosphate groups.

7.3 ATP provides energy for cellular work How is energy released from ATP? Energy is released from ATP when a

phosphate bond is broken.

Concept 7.3 – ATP provides energy for cellular work.

6. What are the three main types of cellular work?

Chemical work, mechanical work, transport work (active transport)

7.4 Electrons fall How is breathing related to cellular

respiration?Breathing brings oxygen into the body that is required by cells for cellular respiration (mitochondria). Breathing also removes the waste product of cellular respiration, carbon dioxide.

Cellular Respiration Equation8. What are the products of cellular respiration?

Carbon dioxide, water, and energy (ATP)

7.5 Cellular Respiration Do you like to run, bike, or swim? These all are

good ways to exercise. When you exercise, your body uses oxygen to get energy from glucose.

1. How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run?

2. What do you think is happening in your cells to cause the changes in how you feel?

3. Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain your answer.

Overview of Cellular Respiration What is cellular respiration?

Cellular respiration is the process that releases energy by breaking down food (glucose) in the presence of oxygen.

Overview of Cellular Respiration What is cellular respiration?

Cellular respiration is the process that releases energy by breaking down food (glucose) in the presence of oxygen.

C6H12O6 + 6 O2 6 H2O + 6 CO2 + Energy

glucose oxygen water carbon ATP dioxide

What would be the problem if cellular respiration occurred in just one step?

Burn up all energy instead of a gradual release of energy

Glucose

Pyruvic acid

Electrons carried in NADH

Electrons carried in NADH and FADH2

Cellular Respiration: An Overview

Section 9-1

GlycolysisKrebs Cycle Electron Transport

Chain

2 2 32 36 Total ATP

Glycolysis First step in cellular respiration

Glyco / lysis – “to break glucose” Does not need oxygen to occur Where does glycolysis take place in the cell?

Glycolysis occurs in the cytoplasm of the cell. Glycolysis

Process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid.

Glycolysis

• How does the cell get glycolysis going? The cell uses energy. 2 molecules of ATP are

used up.

• What are the products of glycolysis? Pyruvate and 4 ATP molecules

C. Glycolysis

• Why is there only a NET of 2 ATP molecules produced during glycolysis? 2 ATP molecules were used to start reaction

What happens after glycolysis???Glycolysis is ALWAYS the first step in the break down

of glucose. Glycolysis does not need oxygen to occur

If oxygen is NOT present, glycolysis is followed by anaerobic respiration.

Alcoholic Fermentation Lactic Acid Fermentation

What happens after glycolysis???Glycolysis is ALWAYS the first step in the break down

of glucose.

If oxygen is NOT present, glycolysis is followed by anaerobic respiration (Fermentation)

Alcoholic Fermentation Lactic Acid Fermentation

If oxygen is present, glycolysis is followed by aerobic respiration – a process that requires oxygen

Anaerobic Respiration: Fermentation

What is fermentation? Fermentation is a process by which cells release energy in the absence

of oxygen. Where does fermentation occur in the cell?

Cytoplasm of the cell. Why is fermentation considered an anaerobic process?

Anaerobic is process that does not require oxygen Fermentation does NOT require oxygen

Anaerobic Respiration: Fermentation Two main types of fermentation

1. Alcohol fermentation2. Lactic acid fermentation

What organisms use alcoholic fermentation o Yeasts and other microorganisms use alcoholic fermentationo Waste products are alcohol and carbon dioxide

What happens to the small amount of alcohol produced during the baking of bread? Evaporates when bread is baked.

Glycolysis Alcoholic Fermentation

How does fermentation allow the production of ATP to continue? NAD+ is looped to start the process over again.

Glycolysis Alcoholic Fermentation

Glycolysis Lactic Acid Fermentation

Section 9-1

2. Lactic Acid Fermentation – • Lactic acid is produced by your muscles

during rapid exercise when not enough oxygen is present.

• Prokaryotes produce lactic acid as a waste product which is used in production of foods: yogurt, cheese, sour cream, sauerkraut, etc.

Glucose 2 Lactic acid2 Pyruvic acid

SUMMARYGlycolysis is ALWAYS the first step in the break down

of glucose.

If oxygen is NOT present, glycolysis is followed by anaerobic respiration.

Alcoholic Fermentation Lactic Acid Fermentation

If oxygen is present, glycolysis is followed by aerobic respiration.

Glycolysis

The Krebs Cycle and Electron Transport1. At the end of glycolysis, how much of the

chemical energy in glucose is still unused?Approx. 90%

2. Because the final stages of cellular respiration require oxygen, they are said to be aerobic.

The Krebs Cycle and Electron Transport

Mitochondrial matrix

Where do the reactions of the Krebs cycle take place in the cell???

The Krebs Cycle and Electron Transport

The Krebs Cycle Second stage of cellular

respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

Electron Transport Chain

Inner membrane of mitochondria

Where do the reactions of the electron transport chain take place in the cell???

The Electron Transport The Electron Transport Chain

series of proteins in which the high-energy electrons from the Krebs cycle are used to convert ADP into ATP

Cellular Respiration and EnergyIn the presence of oxygen, the cell can produce 36 ATP molecules per one glucose molecule

Transfer of Energy to ATPWhere does the energy in food go?

When broken down, the energy gets stored in a molecule known as ATP

ATP delivers energy wherever it is needed in the cell. For example: ATP drives muscle movement Transport of molecules across the cell membrane ATP drives cellular respiration

How does ATP deliver energy to the cell?

It is in it’s structure