Cellular respiration

Cellular respiration: is the process by which cells obtain energy from glucose.

During cellular respiration cells break down glucose and other molecules from food in the presence of oxygen releasing energy.

Living things need a constant supply of energy and carry out cellular respiration continuously.

Students page 457-figure 1

Key concepts: Cells carry out respiration all the time. They

need a constant supply of energy necessary for survival.

Breathing brings oxygen to the lungs. Breathing also rids the body of the waste products of respiration.

Cellular respiration is the burning of glucose in the presence of oxygen to produce energy. Respiration includes both breathing and cellular respiration.

What is the process called that releases energy from glucose? Respiration

Why is respiration important to cells? It provides needed energy for survival

What happens in the first stage of respiration? Glucose is broken down into smaller molecules and a small amount of energy is released.

Where in this cell does this stage takes place? In the cytoplasm.

Two stages of cellular respiration

What happens in the second stage of respiration? The smaller molecules are broken down into even smaller molecules and a large amount of energy is released.

Which stage uses more oxygen? The second stage

Where in the cell does the second stage takes place? In mitochondria.

The cellular respiration equation: Glucose + oxygen------------- carbon dioxide+

water+ energy In other words in the cytoplasm glucose is

broken down into smaller molecules releasing a small amount of energy. In the mitochondria the smaller molecules react producing carbon dioxide, water and large amount s of energy.

Students page 458 look at figure 2 “releasing energy". It shows the process.

Comparing photosynthesis and cellular respiration;

What are the raw materials for photosynthesis? Water and carbon dioxide. ( substances produced as a result of photosynthesis are called products).

What are water and carbon dioxide in cellular respiration? They are products

Comparing two energy processes

What are the products of photosynthesis? Glucose and oxygen

What are those two substances in cellular respiration? They are raw materials

What does this indicate about the two processes? Photosynthesis and cellular respiration are OPPOSITE processes.

Students page 459 Figure 3 ‘the two energy processes”

When there is not enough oxygen to carry out cellular respiration, fermentation occurs.

Fermentation: cells release energy from food without using oxygen.

What are the two types of fermentation? Alcoholic fermentation and lactic acid fermentation.

What are the products of alcoholic fermentation? Alcohol, carbon dioxide, small amount of energy.

Fermentation

What are the products of lactic acid fermentation? Lactic acid, small amount of energy.

How are fermentation and respiration alike and different? Both processes produce energy but fermentation produces less. Fermentation does not use oxygen, whereas respiration does.

Alcoholic fermentation occurs in yeast and single celled organisms. Examples in baking causes dough to rise.

Lactic acid fermentation occurs during exercise. When you feel a painful sensation in your muscles during or after exercising is due to lactic acid fermentation that happened.

Class work : Research details about process of making

cheese. Using construction paper draw your favorite

cheese. Include process of making it, which acid or bacteria is used and how, and how long the process takes before the cheese is sold. You should also list foods that contain your favorite cheese as an ingredient.