Chapter 5 Flashcards
What is metabolism?
Metabolism refers to all the chemical reactions that occur within a living organism to maintain life.
What are the two main types of metabolism?
The two main types of metabolism are catabolism and anabolism.
Define catabolism.
Catabolism is the metabolic process that breaks down molecules to obtain energy.
Define anabolism.
Anabolism is the metabolic process that builds up molecules from smaller units, requiring energy.
What role do enzymes play in metabolism?
Enzymes act as catalysts to speed up the chemical reactions involved in metabolism.
True or False: Enzymes are consumed in the reactions they catalyze.
False: Enzymes are not consumed in the reactions they catalyze.
What is the active site of an enzyme?
The active site is the region on the enzyme where substrate molecules bind and undergo a chemical reaction.
What is a substrate?
A substrate is a molecule upon which an enzyme acts.
Fill in the blank: Enzymes are _____ that lower the activation energy of a reaction.
catalysts
What factors can affect enzyme activity?
Factors include temperature, pH, substrate concentration, and the presence of inhibitors or activators.
What is an enzyme inhibitor?
An enzyme inhibitor is a substance that decreases the activity of an enzyme.
Give an example of a cofactor.
An example of a cofactor is a metal ion, such as zinc or magnesium.
What is the difference between competitive and non-competitive inhibition?
Competitive inhibition occurs when an inhibitor competes with the substrate for the active site, while non-competitive inhibition occurs when the inhibitor binds to an enzyme at a different site.
True or False: All enzymes are proteins.
True: Most enzymes are proteins, although some RNA molecules also have catalytic activity.
What is the significance of enzyme specificity?
Enzyme specificity ensures that enzymes catalyze specific reactions for particular substrates, preventing unwanted side reactions.
What is the term for the maximum rate of reaction in enzyme kinetics?
The term is Vmax.
What does the Michaelis-Menten equation describe?
The Michaelis-Menten equation describes the rate of enzymatic reactions as a function of substrate concentration.
Fill in the blank: The _____ concentration at which the reaction rate is half of Vmax is known as Km.
substrate
What is a metabolic pathway?
A metabolic pathway is a series of chemical reactions in a cell that lead to a product.
What is glycolysis?
Glycolysis is the metabolic pathway that converts glucose into pyruvate, producing ATP and NADH.
What are the end products of glycolysis?
The end products of glycolysis are pyruvate, ATP, and NADH.
True or False: Fermentation occurs in the absence of oxygen.
True: Fermentation is an anaerobic process.
What is the Krebs cycle also known as?
The Krebs cycle is also known as the citric acid cycle.
What is the primary function of the Krebs cycle?
The primary function of the Krebs cycle is to produce electron carriers (NADH and FADH2) and ATP from the oxidation of acetyl-CoA.
What is oxidative phosphorylation?
Oxidative phosphorylation is the process by which ATP is produced using energy derived from the electron transport chain.
What is ATP?
ATP, or adenosine triphosphate, is the primary energy carrier in cells.
Fill in the blank: The _____ theory explains how enzymes and substrates fit together.
lock and key
What is the role of NAD+ in metabolism?
NAD+ acts as an electron carrier in various metabolic reactions.
What are the two main types of cellular respiration?
The two main types of cellular respiration are aerobic respiration and anaerobic respiration.
True or False: Anaerobic respiration produces more ATP than aerobic respiration.
False: Aerobic respiration produces more ATP than anaerobic respiration.
What is the significance of enzymes in biological reactions?
Enzymes lower the activation energy of reactions, allowing them to occur more rapidly and efficiently.
What are allosteric enzymes?
Allosteric enzymes are enzymes that have multiple binding sites and can be regulated by molecules that bind to sites other than the active site.
Fill in the blank: Enzymes that require a coenzyme for activity are called _____ enzymes.
holoenzymes
What is the primary energy currency of the cell?
The primary energy currency of the cell is ATP.
What is substrate-level phosphorylation?
Substrate-level phosphorylation is the direct synthesis of ATP from ADP and a phosphorylated intermediate.
What does it mean for an enzyme to be denatured?
Denaturation refers to the process where an enzyme loses its functional shape and, consequently, its activity.
What is the role of enzymes in digestion?
Enzymes in digestion break down complex food molecules into simpler molecules that can be absorbed by the body.
What is the importance of maintaining optimal pH for enzyme activity?
Maintaining optimal pH is crucial for enzyme activity as extreme pH levels can lead to denaturation and loss of function.
