Lesson 5: Structures, Functions and Roles of Biological Molecules and Enzyme Activity in Metabolism
Biological Molecules/Macromolecules
Plants produce their own food through photosynthesis. They manufacture mainly carbohydrates (glucose) as a source of food of many higher organisms in the food chain. It is one of the many biological molecules present in plants and needed by animals. Biological molecules are macromolecules composed of many monomers (polymer) connected through a covalent bond forming polysaccharides, proteins, and nucleic acids (Table 1). They have specific, characteristic three-dimensional shapes that depend on the structure, properties, and sequence of their monomers important for their biological functioning and their interactions …show more content…
In terms of pH effect, the rates of most enzyme-catalyzed reactions depend on the pH of the medium in which they occur. Enzymes are most active at a particular pH in which activity decreases as the solution is made more acidic or more basic than its (optimal) value. In this case, the active site of an enzyme is affected and may not be properly oriented thus the substrates cannot bind.
In terms of the effect of temperature, the rate of enzyme-catalyzed reaction speeds up at higher temperature because a greater fraction of the reactant molecules have enough energy to provide the activation energy for the reaction. At high temperature, the bonds of enzymes break making it inactive. Heat makes enzymes inactive or denatured making it not functional. Other enzymes denature at temperatures only slightly above that of the human body, but a few are stable even at the boiling or freezing points of water (Purves).
In case of the effect in the amount of substrate, the velocity increases with each increase in substrate concentration but as the substrate concentration becomes larger, the increases in rate produced get smaller and smaller. The reaction reached hyperbola in which the initial velocity approaches a maximum value that is never exceeded. Reactions that show dependence on substrate concentration are said to show saturation kinetics (Bolsover et al., …show more content…
A reaction in which one substance transfers one or more electrons to another substance is called an oxidation–reduction reaction, or redox reaction. Reduction is the gain of one or more electrons by an atom, ion, or molecule while oxidation is the loss of one or more electrons. For example, addition of hydrogen atoms to molecules, or the removal of oxygen atoms, is a reduction while oxidation is the addition of oxygen. Oxygen atoms tend to take more than their fair share of electrons, addition of oxygen means removal of electrons, and vice versa, so reduction is the addition of electrons, with oxidation being defined as the removal of electrons (Bolsover et al.,
Biological Molecules/Macromolecules
Plants produce their own food through photosynthesis. They manufacture mainly carbohydrates (glucose) as a source of food of many higher organisms in the food chain. It is one of the many biological molecules present in plants and needed by animals. Biological molecules are macromolecules composed of many monomers (polymer) connected through a covalent bond forming polysaccharides, proteins, and nucleic acids (Table 1). They have specific, characteristic three-dimensional shapes that depend on the structure, properties, and sequence of their monomers important for their biological functioning and their interactions …show more content…
In terms of pH effect, the rates of most enzyme-catalyzed reactions depend on the pH of the medium in which they occur. Enzymes are most active at a particular pH in which activity decreases as the solution is made more acidic or more basic than its (optimal) value. In this case, the active site of an enzyme is affected and may not be properly oriented thus the substrates cannot bind.
In terms of the effect of temperature, the rate of enzyme-catalyzed reaction speeds up at higher temperature because a greater fraction of the reactant molecules have enough energy to provide the activation energy for the reaction. At high temperature, the bonds of enzymes break making it inactive. Heat makes enzymes inactive or denatured making it not functional. Other enzymes denature at temperatures only slightly above that of the human body, but a few are stable even at the boiling or freezing points of water (Purves).
In case of the effect in the amount of substrate, the velocity increases with each increase in substrate concentration but as the substrate concentration becomes larger, the increases in rate produced get smaller and smaller. The reaction reached hyperbola in which the initial velocity approaches a maximum value that is never exceeded. Reactions that show dependence on substrate concentration are said to show saturation kinetics (Bolsover et al., …show more content…
A reaction in which one substance transfers one or more electrons to another substance is called an oxidation–reduction reaction, or redox reaction. Reduction is the gain of one or more electrons by an atom, ion, or molecule while oxidation is the loss of one or more electrons. For example, addition of hydrogen atoms to molecules, or the removal of oxygen atoms, is a reduction while oxidation is the addition of oxygen. Oxygen atoms tend to take more than their fair share of electrons, addition of oxygen means removal of electrons, and vice versa, so reduction is the addition of electrons, with oxidation being defined as the removal of electrons (Bolsover et al.,