Energy, Metabolism, and Cells – Photosynthesis & Cellular Respiration

Enzymes are known as protein catalysts. The name protein catalyst suggests that most enzymes are made of proteins. A catalyst is a substance that speeds up chemical reactions without being consumed in the process. (Giuseppe, M 2002, p.69). After a reaction has been catalyzed, the catalyst can be used again to catalyze the same reaction. Enzymes reduce the activation energy (minimal energy) it takes for a reaction to take place. Enzymes can either catabolize (destroy), or anabolize (build up) a chemical system.

Both photosynthesis and cellular respiration are the main pathways of energy transportation in organisms. However, the reactants and the products are exact opposites in photosynthesis and in cellular respiration.

Photosynthesis occurs each time the sun’s light reaches the lives of a plant. The chemical ingrediants for photosynthesis are carbon dioxide (CO2), a gas that passes from the air into a plant via tiny pores, and water (H20), which absorbed from the soil by the plant’s roots. Inside leaf cells, tiny structures called chloroplasts use light energy to rearrange the atoms of the ingrediants to produce sugars, most importantly glucose (C6H12O6) and other organic molecules. Chlorophyll gives the plant its green color (Simon, 02/2012, pp. 92-93). Chemical reactions transfers the sun’s light energy into the chemical bonds that hold energy-carrying molecules. The most common are

Enzymes catalyze chemical reactions by lowering the activation energy. To be more specific, the enzymes have a pocket called an active site where substrates, which are the reactants of the reaction, can bind to. Once they are bound, the complex is called an enzyme-substrate complex. The catalytic action of the enzyme converts the substrate to products by stretching, stressing, and bending bonds to break them and make it easier to get to the transition state where the molecules can form new bonds. The amount of free energy needed to go forth with the reaction decreases, as a result.

Enzymes are types of proteins that work as a substance to help speed up a chemical reaction (Madar & Windelspecht, 104). There are three factors that help enzyme activity increase in speed. The three factors that speed up the activity of enzymes are concentration, an increase in temperature, and a preferred pH environment. Whether or not the reaction continues to move forward is not up to the enzyme, instead the reaction is dependent on a reaction’s free energy. These enzymatic reactions have reactants referred to as substrates. Enzymes do much more than create substrates; enzymes actually work with the substrate in a reaction (Madar &Windelspecht, 106). For reactions in a cell it is

Enzymes are biological catalysts, which speed up the rate of reaction without being used up during the reaction, which take place in living organisms. They do this by lowering the activation energy. The activation energy is the energy needed to start the reaction.

Enzymes are biological catalysts that facilitate specific chemical reactions (Raven, et al., 2014). Enzymes do their job by

Enzymes are biological catalysts, which accelerate the speed of chemical reactions in the body without being used up or changed in the process. Animals and plants contain enzymes which help break down fats, carbohydrates and proteins into smaller molecules the cells can use to get energy and carry out the processes that allow the plant or animal to survive. Without enzymes, most physiological processes would not take place. Hundreds of different types of enzymes are present in plant and animal cells and each is very specific in its function.

Enzymes are proteins that act as catalysts during a biochemical process. Catalysts are non-changing enzymes that can increase or decrease activation energy to accelerate or slow down a biochemical reaction without using additional energy.

Living cells within our bodies perform an abundance of chemical reactions very speedily because of the participation of enzymes. Enzymes are biological catalysts that speed up a chemical reaction without being depleted or altered in the reaction (Garrette & Grisham, 1999). The

All living things ultimately depend on this process. The compounds plants make during photosynthesis provide nutrients and energy to organisms that consume plants. Organisms that consume the plant-eaters gain nutrients and energy from them, so both energy and materials are passed from organism to organism.

Also, unlike photosynthesis, cellular respiration is known as a decomposition reaction. During this reaction, the exergonic release of energy is produced by breaking glucose down into smaller ATP molecules, water and carbon dioxide which is released into the air, for use by plants, every time we exhale

Enzymes are a key aspect in our everyday life and are a key to sustaining life. They are biological catalysts that help speed up the rate of reactions. They do this by lowering the activation energy of chemical reactions (Biology Department, 2011).

There are thousands of chemical reactions that occur in a cell at every moment. These chemical reactions do not occur randomly, they are highly under the control of biological catalysts called enzymes. Most of these enzymes are proteins. These proteins have certain primary structures directed by

Organisms cannot depend solely on spontaneous reactions for the production of materials because they occur slowly and are not responsive to the organism's needs (Martineau, Dean, et al, Laboratory Manual, 43). In order to speed up the reaction process, cells use enzymes as biological catalysts. Enzymes are able to speed up the reaction through lowering activation energy. Additionally, enzymes facilitate reactions without being consumed (manual,43). Each enzyme acts on a specific molecule or set of molecules referred to as the enzyme's substrate and the results of this reaction are called products (manual 43). As a result, enzymes promote a reaction so that substrates are converted into products on a faster pace (manual 43). Most enzymes are proteins whose structure is determined by its sequence of its amino acids. Enzymes are designed to function the best under physiological conditions of PH and temperature. Any change of these variables that change the conformation of the enzyme will destroy or enhance enzyme activity(manual, 43).