Housekeeping: It's my understanding that Thursday is a holiday. That means I'll see you guys today and Wednesday. It throws off my plans to have you do a lab this week, so we're pushing it to next week.
Agenda:
1. Macromolecules Review
2. Water
3. Chemical Reactions
Content Review:
Links: Biochem Basics Macromolecules
Textbook Readings:
Student Missions:
Mission 1: Well, It's What We're Made Of, Right?
Mission Objectives. You should be able to...
1. List and describe the essential properties of water.
2. Explain the necessity of hydrogen bonding.
3. Explain the solubility of water and its relationship to transporting molecules in organisms.
Water is the medium of life. Understanding why it is so important requires understanding of its structure. There are two hydrogen ions sharing electrons with an oxygen ion. Sharing of electrons results in a covalent bond. The water molecule is polar, meaning that it has a net charge on one end (the oxygen end). As a result, water can interact with itself and other molecules in different ways. Water has many different properties which makes it so important in living organisms.
Agenda:
1. Macromolecules Review
2. Water
3. Chemical Reactions
Content Review:
Links: Biochem Basics Macromolecules
Textbook Readings:
Student Missions:
Mission 1: Well, It's What We're Made Of, Right?
Mission Objectives. You should be able to...
1. List and describe the essential properties of water.
2. Explain the necessity of hydrogen bonding.
3. Explain the solubility of water and its relationship to transporting molecules in organisms.
Water is the medium of life. Understanding why it is so important requires understanding of its structure. There are two hydrogen ions sharing electrons with an oxygen ion. Sharing of electrons results in a covalent bond. The water molecule is polar, meaning that it has a net charge on one end (the oxygen end). As a result, water can interact with itself and other molecules in different ways. Water has many different properties which makes it so important in living organisms.
Just to make sure you have a handle on what's going on with water, here's a link to help you understand.
Mission 2: Enzymes...Real & True Speed Demons!
Mission Objectives. You should be able to...
1. Describe the function of an enzyme.
2. Explain how an enzyme/substrate is a chemical reaction.
3. List and describe the factors that affect enzyme-catalyzed reactions.
Enzymes are biological catalysts that have specific functions. The reactants for this chemical reaction are called substrates. They bind to the enzyme on the active site, matching up according to their shapes. Once this process occurs, the active site changes shape and the bonds in the reactants are broken down and new bonds are formed into products.
Take a look at this animation. And here is the Amoeba Sisters' take on it.
Mission 2: Enzymes...Real & True Speed Demons!
Mission Objectives. You should be able to...
1. Describe the function of an enzyme.
2. Explain how an enzyme/substrate is a chemical reaction.
3. List and describe the factors that affect enzyme-catalyzed reactions.
Enzymes are biological catalysts that have specific functions. The reactants for this chemical reaction are called substrates. They bind to the enzyme on the active site, matching up according to their shapes. Once this process occurs, the active site changes shape and the bonds in the reactants are broken down and new bonds are formed into products.
Take a look at this animation. And here is the Amoeba Sisters' take on it.
Factors that affect enzyme-catalyzed reactions:
Temperature. Increasing temperature increases the speed at which molecules move and thus collide. This happens with or without enzymes. However, there is an upper limit to which enzymes can affect reaction rates. This is based on the temperature at which the enzyme denatures and loses its 3D shape.
pH. Negative and positive areas of a substrate must match the opposite charge when the substrate hits the active site of the enzyme in order for the catalytic properties to work. Solutions that are too acidic (that have more H+) cause the H ions to bond to the negative charge on the enzyme or substrate and prevent proper charge matching. Same thing happens with solutions that are too basic (more OH-). Either situation causes the enzymes to be less efficient and possibly denature or be ineffective. Most enzymes work best at a pH of near 7 (neutral) with the exception of stomach digestive enzymes. The stomach is highly acidic.
Concentration of the substrate. Increasing concentration increases reaction rates because of the number of collisions increase. However, like temperature effects, there is an upper limit because when the enzymes are working at optimal levels, adding more substrate won't increase collisions.
Activity: Get to know enzymes on an interactive level with Bioman's Enzymatic Game. Complete the interactive and take the quiz. You only get one chance. Screen-shot your quiz score and send it to me at [email protected]
Mission 3: Chemical Reactions
Mission Objectives. You should be able to...
1. Explain what happens in a simple chemical reaction.
2. Describe the processes of photosynthesis and respiration.
3. Differentiate between endothermic and exothermic reactions.
4. Identify parts of a chemical reaction graph.
Chemical reactions are the process by which elements and/or compounds change into new substances. Chemical equations are written representations of chemical reactions and you can see that the atoms are rearranged. The substances on the left are called reactants and the substances on the right are called products.
In biology, there are two key chemical reactions that you need to be aware of: photosynthesis & respiration. They are complementary processes. Photosynthesis takes place in chloroplasts and respiration takes place in mitochondria. Photosynthesis requires carbon dioxide, water and energy (in the form of sunlight) to produce glucose (a simple sugar) and oxygen. Respiration requires glucose and oxygen and transforms it into carbon dioxide, water and energy (in the form of ATP).
As you can see, both equations are balanced. Any chemical equation must be balanced because mass is always conserved.
Temperature. Increasing temperature increases the speed at which molecules move and thus collide. This happens with or without enzymes. However, there is an upper limit to which enzymes can affect reaction rates. This is based on the temperature at which the enzyme denatures and loses its 3D shape.
pH. Negative and positive areas of a substrate must match the opposite charge when the substrate hits the active site of the enzyme in order for the catalytic properties to work. Solutions that are too acidic (that have more H+) cause the H ions to bond to the negative charge on the enzyme or substrate and prevent proper charge matching. Same thing happens with solutions that are too basic (more OH-). Either situation causes the enzymes to be less efficient and possibly denature or be ineffective. Most enzymes work best at a pH of near 7 (neutral) with the exception of stomach digestive enzymes. The stomach is highly acidic.
Concentration of the substrate. Increasing concentration increases reaction rates because of the number of collisions increase. However, like temperature effects, there is an upper limit because when the enzymes are working at optimal levels, adding more substrate won't increase collisions.
Activity: Get to know enzymes on an interactive level with Bioman's Enzymatic Game. Complete the interactive and take the quiz. You only get one chance. Screen-shot your quiz score and send it to me at [email protected]
Mission 3: Chemical Reactions
Mission Objectives. You should be able to...
1. Explain what happens in a simple chemical reaction.
2. Describe the processes of photosynthesis and respiration.
3. Differentiate between endothermic and exothermic reactions.
4. Identify parts of a chemical reaction graph.
Chemical reactions are the process by which elements and/or compounds change into new substances. Chemical equations are written representations of chemical reactions and you can see that the atoms are rearranged. The substances on the left are called reactants and the substances on the right are called products.
In biology, there are two key chemical reactions that you need to be aware of: photosynthesis & respiration. They are complementary processes. Photosynthesis takes place in chloroplasts and respiration takes place in mitochondria. Photosynthesis requires carbon dioxide, water and energy (in the form of sunlight) to produce glucose (a simple sugar) and oxygen. Respiration requires glucose and oxygen and transforms it into carbon dioxide, water and energy (in the form of ATP).
As you can see, both equations are balanced. Any chemical equation must be balanced because mass is always conserved.
Chemical reactions require energy. The minimum amount of energy needed for reactants to form products is called activation energy. (Ea) Once this threshold is reached, no further input of energy is required. If you are looking at an energy curve, the peak represents activation energy. Exothermic reactions are reactions where energy is released because the energy of the reactants is higher than the energy of the products. Endothermic reactions are reactions where energy is absorbed because the energy of the products is higher than the energy of the reactants.
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