Notes Biology
Biology- Maintaining a Balance Summary
1. Most organisms are active in a limited temperature range
1. identify the role of enzymes in metabolism, describe their chemical composition and use a simple model to describe their specificity on substrates
Enzymes are proteins which act as catalysts in living things (they lower the amount of energy needed for a reaction, therefore increasing rate of reaction). Enzymes speed up reactions but are not used up by them. Enzymes catalyze only one specific reaction. For a biochemical pathway requiring multiple steps many different enzymes are required.
Model- The Lock and Key Model
At a molecular level, the shape of an enzyme permits it to bind at a particular site (active site) to the substrate molecules, causing a reaction to occur. This can be thought of as a key (the substrates) fitting a lock (the enzyme). Unless a key is right for a particular lock it doesn’t work. Enzymes are specific because they will only fit particular substrates.
[pic]
2. identify the pH as a way of describing the acidity of a substance
pH measures acidity on a scale where 7 is neutral, numbers less than 7 are acidic and numbers greater than 7 are basic or alkaline.
3. explain why the maintenance of a constant internal environment is important for optimal metabolic efficiency
Most metabolism (chemical reactions in a living thing) is controlled by enzymes. Therefore, for an organism to function efficiently, so must its metabolism. Thus, optimal conditions for enzyme activity need to be maintained for optimal metabolic efficiency. These conditions are temperature, pH level, substrate concentration and enzyme concentration.
4. describe homeostasis as the process by which organisms maintain a relatively stable internal environment
Homeostasis is the maintenance of a steady state/constant environment by means of physiological or behavioral feedback responses. It is important because it maintains the optimal
1. Most organisms are active in a limited temperature range
1. identify the role of enzymes in metabolism, describe their chemical composition and use a simple model to describe their specificity on substrates
Enzymes are proteins which act as catalysts in living things (they lower the amount of energy needed for a reaction, therefore increasing rate of reaction). Enzymes speed up reactions but are not used up by them. Enzymes catalyze only one specific reaction. For a biochemical pathway requiring multiple steps many different enzymes are required.
Model- The Lock and Key Model
At a molecular level, the shape of an enzyme permits it to bind at a particular site (active site) to the substrate molecules, causing a reaction to occur. This can be thought of as a key (the substrates) fitting a lock (the enzyme). Unless a key is right for a particular lock it doesn’t work. Enzymes are specific because they will only fit particular substrates.
[pic]
2. identify the pH as a way of describing the acidity of a substance
pH measures acidity on a scale where 7 is neutral, numbers less than 7 are acidic and numbers greater than 7 are basic or alkaline.
3. explain why the maintenance of a constant internal environment is important for optimal metabolic efficiency
Most metabolism (chemical reactions in a living thing) is controlled by enzymes. Therefore, for an organism to function efficiently, so must its metabolism. Thus, optimal conditions for enzyme activity need to be maintained for optimal metabolic efficiency. These conditions are temperature, pH level, substrate concentration and enzyme concentration.
4. describe homeostasis as the process by which organisms maintain a relatively stable internal environment
Homeostasis is the maintenance of a steady state/constant environment by means of physiological or behavioral feedback responses. It is important because it maintains the optimal