Enzymes speed up the rates of reactions within the body. An enzyme acts by binding to a substrate, the substance that will be acted on by the enzyme. When the substrate binds to the enzyme, the reaction takes place.Know More
The enzyme has a region called the active site, and this is what the substrate binds to. The enzyme and the substrate do not react with one another; rather, the enzyme brings down the amount of energy needed for the reaction to occur, the activation energy. Negative feedback will cease the reaction. With negative feedback, the end product of the reaction will fit into another site of the enzyme and inhibit its activity. The induced-fit model of enzyme action states that when a substrate binds to an enzyme, the enzyme causes the substrate to change its shape, speeding up the reaction even more.
Because enzymes are proteins, they can work only under certain conditions of temperature and pH. If conditions are not optimal for the enzyme, it becomes ineffective. Extreme conditions of temperature and pH denature enzymes, changing their shapes so much that they are rendered useless.
The actions of enzymes can be inhibited in two ways. In competitive inhibition, the inhibitor molecule binds to the active site, not allowing the substrate to bind. With non-competitive inhibition, the inhibitor molecule binds to another location on the enzyme, changing the structure of the active site so that no substrate can bind.Learn More
Internal respiration takes place in the tissues of the body with the exchange of gases between systemic capillaries and surrounding tissue fluid, according to the McGraw-Hill College Division. In contrast, external respiration is the exchange of gases between air in the alveoli of the lungs and blood in pulmonary capillaries.Full Answer >
Hemoglobin is the protein used in the blood of all vertebrates to transport oxygen from the lungs to the tissues in the body. A major constituent of blood is water, and since oxygen is not very soluble in water, a protein, hemoglobin, must be used.Full Answer >
According to Science NetLinks, cells convert energy for your body and continually divide to make more cells for growth and repair. The body has about 200 different types of cells, and specific cells have assorted jobs to do. The various shapes of body cells depends on each cell's job.Full Answer >
Specialized cells are cells that have gone on to specialize in being in a certain part of the body, such as a skin cell. These cells generally do not replicate and simply die after their life cycle is complete. Most of the human body's cells are specialized cells, such as muscle, skin and nerve cells.Full Answer >