Chemical Reactions
What is the law stating that mass is neither created nor destroyed during a reaction?
Law of Conservation of Mass.
What is metabolism?
The sum of all chemical reactions in a cell that provide energy for life.
What is an enzyme?
A protein that speeds up biochemical reactions by lowering activation energy.
What does ATP stand for?
Adenosine Triphosphate.
What is an endothermic reaction?
A reaction that absorbs energy, often in the form of heat or light.
Define reactants and products in a chemical reaction
Reactants are the substances that undergo change, while products are the substances produced as a result of the reaction.
What is activation energy?
The energy needed to initiate a chemical reaction.
How do enzymes speed up reactions?
By providing an active site that facilitates the binding of substrates, thus lowering the activation energy.
What role does ATP play in the cell?
It serves as the main energy currency, carrying energy for cellular processes.
What is an exothermic reaction?
A reaction that releases energy, often in the form of heat or light.
What is another name for a reactant?
Substrate
Explain the law of conservation of energy.
Energy is neither created nor destroyed
What is meant by "induced fit"?
The change in shape of an enzyme when a substrate binds, allowing for a tighter fit
How is energy released from ATP?
Energy is released when the bond between the second and third phosphate groups is broken.
Give an example of an endothermic reaction.
Photosynthesis.
What are the two types of reactions based on energy release?
Endothermic (absorbs energy) and Exothermic (releases energy).
How do enzymes affect metabolic reactions?
Enzymes lower the activation energy required for reactions, thus speeding them up.
Why are enzymes called catalysts?
Because they speed up reactions without being permanently altered or consumed in the process.
Describe phosphorylation and dephosphorylation.
Phosphorylation is the addition of a phosphate group to ADP to form ATP; dephosphorylation is the removal of a phosphate group from ATP, forming ADP.
What happens to energy in an exothermic reaction?
Energy is released to the surroundings, typically as heat.
What does it mean to balance a chemical equation?
It means ensuring that the number of atoms for each element is the same on both sides of the equation.
What is the difference between catabolic and anabolic reactions?
Catabolic reactions break down larger molecules and release energy, while anabolic reactions build larger molecules from smaller ones and require energy.
What might cause an enzyme to become denatured?
Extreme changes in pH, temperature, or ionic strength can deform the enzyme's active site.
Explain the ATP-ADP cycle.
ATP is converted to ADP and a phosphate when energy is released; ADP can be converted back to ATP by adding a phosphate using energy from food.
How can temperature affect the rate of a reaction?
Increasing temperature generally increases reaction rate by causing molecules to move faster and collide more frequently.