Photosynthesis (environmental science)

Energy production

We burn fossil fuels such as coal and petroleum to generate fuel used, for example, to run our homes and cars. Burning fossil fuels releases harmful chemicals into the atmosphere. So, botanists look for cleaner fuel options. Scientists use crops such as corn to create biofuels, which are fuels obtained from living things. These fuels are less harmful to the environment.

Using Energy for Fuel

We learned how plants create glucose during photosynthesis. The glucose is stored in the plant until the plant needs to convert it into energy for use in the cell. Watch the video on the next screen to see how this process works.

Manufacturing industries

We wear cotton clothes, use ropes for tying, and read the newspaper every day. Materials such as cotton and paper are derived from plants. These materials don't pollute the environment. Botanists can research and possibly find new plant-based materials that are environmentally friendly and fit for human use.

Careers in Science: Botanist

We've learned how plants create energy to grow. A scientist who studies plants and their functions is called a botanist. Several industries require the skills of botanists. Let's look at some of them.

Light energy

Chlorophyll is present in chloroplasts, organelles seen only in plant cells. This green-colored pigment absorbs light in tiny units of photons. Chlorophyll absorbs all the other colors of light except green, which it reflects. So, we see the color of leaves as green.

Part 2 of fermentation

Both types of fermentation—lactic acid fermentation and alcoholic fermentation—are useful for people. People can become breathless while exercising. This breathlessness happens because when we exercise, we don't get enough oxygen. In this case, lactic acid fermentation occurs. It breaks down glucose into energy. The food industry also uses both types of fermentation. Companies use the useful bacteria from lactic acid fermentation to make yogurt. Bacteria in yeast carry out alcoholic fermentation, making bread dough rise. This fermentation results in soft, spongy bread.

Part 2 of using energy for fuel

Although photosynthesis is an important life process, only plants and a few organisms perform this process. However, all living organisms need energy to perform the basic functions of life. When we eat food, cellular respiration in our bodies digests the food and releases energy. In eukaryotes, this process takes place in the cytoplasm and mitochondria. Respiration also takes place in prokaryotic organisms, such as bacteria. Because prokaryotes lack cell organelles, respiration doesn't occur in the mitochondria.

Botonist

Botany is an important part of many different branches of science. When scientists research plants, they may come across some interesting findings. Watch the video on the next screen to learn about a few unusual plants and how they grow.

Glucose

During photosynthesis, chemical reactions in the chloroplasts convert carbon dioxide and water into glucose and oxygen using light energy. Plants use glucose as fuel.

Making Energy

Energy is the power needed to cause a change. For example, energy is in action when people kick or throw a ball and even when they start a car. People need energy for bodily functions such as pumping blood from the heart and digesting food. Many organisms, including humans, can't make their own energy. We consume energy to function well. Such organisms are called heterotrophs. Plants make their own energy, so they're called autotrophs. Plants make energy in the presence of sunlight in a process called photosynthesis. Although plants need Sun to make energy, they can't use the Sun's energy directly. Plants convert energy into a usable form through photosynthesis. Plants use the Sun's energy, water, and carbon dioxide to create glucose. Plants use this simple form of carbohydrate to carry out their functions. Photosynthesis also releases oxygen, a life-giving element for most living organisms.

Agriculture

Geneticists who specialize in botany can alter plant genes to produce healthier, disease-resistant plants. Botanists also work with farmers, food manufacturers, and pest-control workers to produce healthy crops.

Fermentation

Our bodies release energy through cellular respiration. We need oxygen to carry out respiration. Therefore, oxygen is an important part of our lives. But there may be times when we have low levels of oxygen. For example, when we exercise hard, we create energy through fermentation. Fermentation takes place in the cytoplasm for both prokaryotic organisms and eukaryotic organisms. During fermentation, glucose is broken down into ATP (energy) and lactic acid. This process is called lactic acid fermentation. When glucose breaks down into ATP, alcohol, and CO2, it's called alcoholic fermentation. Both types of fermentation produce less ATP than cellular respiration does. That's why fermentation occurs only when the oxygen level in the body is low.

The photosynthesis reaction

Photosynthesis involves various chemical reactions. These reactions cause the original components to change into chemically different products. To help us understand these reactions, scientists use chemical equations. We learned that in photosynthesis, the reaction begins with water and carbon dioxide. Using light energy, plants make glucose and oxygen. Because we find chemically different products at the end of the reaction, we need to balance them in the chemical equation. For example, when we write the chemical equation, there are six carbon atoms from glucose in the output. So, there should also be six carbon atoms in the input. To balance the equation, we write the number 6 next to the CO2 molecule. The same is true with oxygen and hydrogen, where 12 hydrogen atoms from the water molecule give 12 hydrogen atoms in the glucose molecule.

Water

Plants absorb the water in soil through their roots.

How Plants Create Energy

Plants create energy in the presence of sunlight.

What Is Photosynthesis?

Plants grow in many different places. They make their own food through photosynthesis. The word photosynthesis can be split into two words, photo and synthesis. Photo means "light," and synthesis means "to make something." So, photosynthesis means "to make something from light." All plants use photosynthesis to create their food, or energy, in the presence of sunlight. An important component in photosynthesis is chlorophyll, the pigment that gives leaves their green color. Many trees lose their leaves in winter. Other trees have red or yellow leaves. People sometimes wonder how these trees stay alive without making food, because photosynthesis occurs only in green leaves. Complete the activity on the next screen to learn more about leaf color and photosynthesis.

Oxygen

Plants release oxygen into the atmosphere where most organisms use it to breathe

Pharmaceutical industry

Several medicines contain chemicals derived from plants. Some plants are also used directly as home remedies. Botanists research plants that have a healing effect on people.

Carbon dioxide

When we breathe, we take in oxygen and exhale carbon dioxide. During photosynthesis, plants take in carbon dioxide and release oxygen. One of the reasons we're encouraged to grow more trees is because they give us oxygen. During the peak of photosynthesis, in the presence of sunlight, plants take in higher levels of carbon dioxide and release more oxygen.

Ecology and conservation

When we cut down plants, the number of animals that survive on these plants is reduced. This in turn affects the carnivorous animals that depend on plant-eating animals for food. Botanists can work with conservationists to classify and encourage the growth of different plant species. This step will prevent rare species of plants from becoming endangered.

Cellular Respiration

When we think of respiration, we imagine inhaling oxygen and exhaling carbon dioxide. Cellular respiration occurs inside cells. This process converts glucose into energy for the cells.

A student conducts a science experiment in which she places four identical plants under four different colors of light: red, white, yellow, and green. She measures their height after a few weeks. Under which color of light will the plant grow the least? - green - red - white - yellow

green