Photosynthesis

Elodea Experiment

• In this experiment we will explore what is known as plant pearling, a process that occurs in aquatic plant species as a result of photosynthesis.

• Plant pearling is when bubbles of oxygen accumulate on the leaves of plants and sometimes float to the top of the aquarium like in a glass of campaign.

• It’s a sign that you have a healthy environment in your aquarium.

Elodea Experiment

• http://youtu.be/40Zwv1oxAXU• Elodea Experiment

Photosynthesis

• Photosynthesis is the process by which a cell captures energy and uses it to make food.

• Almost all living things obtain energy either directly or indirectly from the energy of sunlight that is captured during photosynthesis.

Photosynthesis

• Plants make their own food through the process of photosynthesis.

• An organism that makes its own food is called an autotroph.

Photosynthesis

• http://www.neok12.com/php/watch.php?v=zX4b7a504d047d5b6e660173&t=Photosynthesis

Photosynthesis

• An organism that cannot make its own food is called a heterotroph.

• Many heterotrophs obtain food by eating other organisms.

Photosynthesis

• During photosynthesis, plants and some other organisms absorb energy from the sun and use the energy to convert carbon dioxide and water into sugars and oxygen.

Photosynthesis

• Photosynthesis occurs mostly in the leaves of plants where the chloroplasts, green organelles in plant cells are.

• Chlorophyll is a pigment in chloroplasts that is responsible for photosynthesis.

Photosynthesis

• During stage 1, water in the chloroplasts is split into hydrogen and oxygen.

• The oxygen is given off as a waste product as seen in aquatic plants undergoing the process of pearling.

• The oxygen exits the leaf through openings on its underside.

Photosynthesis

• During Stage 2 of photosynthesis cells use the hydrogen that was split off from the water, energy from the sun, and the carbon dioxide from the air to produce sugars.

• Some of these sugars are used to give plants energy while others are stored.

Cellular Respiration

• During cellular respiration, cells break down glucose and other molecules from food in the presence of oxygen to release energy.

• Breathing removes the waste product of cellular respiration (carbon dioxide) from your body.

Cellular Respiration

• During the first stage of cellular respiration the molecule of glucose (the sugar) is broken down in the cytoplasm of the cell.

• Then, in the second stage, oxygen is used to break down molecules even more to produce energy.

• The second stage of cellular respiration occurs in the mitochondria, the powerhouse of the cell.

Powering the Cell: Mitochondria

• This is what it looks like inside of your cell as cellular respiration is occurring right now.

• http://youtu.be/RrS2uROUjK4

Comparing Cellular Respiration and Photosynthesis

Fermentation

• Some organisms can live in the absence of oxygen through a process called fermentation.

• Fermentation is an process in which cells release energy from food without using oxygen.

• Making cheese is a process that uses fermentation

• http://youtu.be/776I-YD6jDo

Fermentation

• Alcoholic fermentation is a type of fermentation that occurs in yeast and other single-celled organisms.

• It produces alcohol, carbon dioxide and some energy.

• Bakers and brewers use yeast to make bread rise and drinks sparkle.

Fermentation

• What evidence can you see of a product of alcoholic fermentation in this picture?

Fermentation

• Lactic Acid Fermentation occurs in your muscles when you exercise when your muscle cells use oxygen faster than it can be replaced.

• A product of this type of fermentation is lactic acid.

Fermentation

• When lactic acid builds up in your muscles, your muscles feel weak and sore.

• Later, when your cells get more oxygen, the lactic acid will break down and the pain will go away.