Enzymes are essential to cell function, yet they also respond to internal environmental factors that affect their activity. For instance, oxygen levels, concentrations of enzyme and substrate, temperature, and pH all affect how efficiently enzymes function.
Studying proteins in the lab or trying to decipher an egg’s inner workings might surprise you that even small changes to its environment can have profound effects on its performance and how it reacts when activated. It’s this sensitivity that makes enzymes so essential for our survival and how our bodies operate.
- Temperature Shifts
Heat can break hydrogen and ionic bonds that keep an enzyme’s active site shape together, altering its ability to bind with substrate molecules and, consequently, decreasing its activity.
- Dramatic Shifts in pH
Acidity can dramatically alter an enzyme’s active site shape, decreasing its ability to bind with substrate molecules and thus slowing down the reaction.
- High Substrate Concentrations
Enzymes’ efficiency at catalyzing reactions is heavily based on their capacity for binding with substrate molecules. A higher substrate concentration usually results in faster reactions, however, this may not always be the case and could differ depending on the type of enzyme and its substrate affinity.
- Alterations in Plasma Levels
Plasma is the fluid within an organism and contains a variety of chemical substances and reactions that take place. These processes form the basis for all life and include many metabolic processes requiring enzymes for participation.
- Changes in Pressure
An organism’s internal environment plays a significant role in how efficiently enzymes function. Low pressure, for instance, may impede hemoglobin proteins – responsible for transporting oxygen between all blood cells – from doing their job properly.
- pH Changes
The pH level in the blood plays a significant role in how well enzymes function. Most are designed to operate within specific ranges of acidic or basic pH, keeping them in optimal working conditions so they can do their jobs most effectively.
- Inhibitors and Cofactors
Enzymes require specific non-protein helper molecules in order to function. These may temporarily attach via ionic or hydrogen bonds, or they can permanently adhere through stronger covalent bonds.
The binding of these molecules is known as activation, and it’s what allows them to catalyze a reaction. Some activators are naturally produced by an organism while others come from environmental or body toxins.
Enzymes all share a core structure composed of polypeptide chains of amino acids. They can even form tertiary structures through interactions between these amino acids and motifs such as alpha-helices and beta sheets.