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 about Cells
According to the Infoplease website from Pearson Education, the biological importance of osmosis is that it facilitates the distribution of essential nutrients in the body and the excretion of metabolic waste products. Cells have semipermeable membranes, and osmosis makes it possible for liquid solvents to pass through these cell membranes.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 >
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 >
White blood cells help to recognize when a foreign and potentially harmful pathogen enters the body, and they respond by releasing antibodies, such as lymphocytes and phagocytes, which attach to the pathogen and work to eradicate it. A high amount of white blood cells are found in the lymph nodes, which is why a symptom or sign of infection in the body can be evident by swollen lymph nodes.Full Answer >