Cellular Respiration Chapter 3, Section 4

What is Respiration? Food supplies your body with glucose, an energy-rich sugar. Respiration is the process by which cells obtain energy from glucose. During respiration, cells break down simple food molecules such as sugar and release the energy they contain.

Photosynthesis Plants capture energy during photosynthesis and save it in the form of carbohydrates, including sugars and starches.

When cells need energy, they withdraw it by breaking down the carbohydrates in a process called respiration.

Two Meanings of Respiration: Breathing – moving air in and out of your lungs. 2. Cellular Respiration – process that takes place inside the cell.

Two Stages of Respiration In the cytoplasm, molecules of glucose are broken down into smaller particles. Oxygen is NOT involved and only a small amount of energy is released. 2. Inside the mitochondria the small molecules of glucose are broken down into smaller molecules again. This time oxygen and energy are both used.

Products of Respiration Once the glucose has been broken down the products of respiration are: 1. carbon dioxide 2. water These products diffuse out of the cell and eventually are breathed out of the body.

Respiration Materials Needed The raw materials for respiration are sugar and oxygen. Plants and some other organisms make their own sugar. Animals and some organisms use the glucose in their cells that came from foods that they consume. The water used comes from air or water surrounding the organism.

The Respiration Equation >>>>>>>>>> C6H1206 + 6 02 (chemical reaction) 6C02 + 6H20 a sugar oxygen carbon water dioxide ***NOTICE: This is the opposite formula for photosynthesis!

Label Stage 1 and Stage 2 of Respiration (see page 92) Cytoplasm Energy mitochondria

Photosynthesis vs. Respiration Respiration is the opposite of the equation for photosynthesis! Sugar + Oxygen produces Carbon and Water Dioxide

Fermentation Some cells obtain energy from food without the use of oxygen. Ex. single-celled organisms deep in the ocean or in the mud of swamps and lakes. Fermentation provides energy for cells without using oxygen.

Alcoholic Fermentation Baker and brewers use yeast to aid in fermentation. Alcohol is a product of this type of fermentation.

Lactic Acid Fermentation Inside your body a different type of fermentation takes place. When you exercise sometimes you use up oxygen in your muscles so quickly that your cells had to supply your body with energy. This type of fermentation is known as lactic acid fermentation. When lactic acid builds up, you feel pain in your muscles.