AP BIO Unit 3 notes

What is the role of enzymes in biological reactions?

Enzymes act as biological catalysts that speed up the rate of reactions without being chemically changed in the process.

What does it mean for enzymes to be 'reusable'?

Enzymes can be used repeatedly in reactions as long as their active site remains unchanged and they haven't been denatured.

What is activation energy?

Activation energy is the initial energy required for a biochemical reaction to occur.

How do enzymes affect activation energy?

Enzymes lower the activation energy by providing a specific site for the substrate to meet, which makes the reaction occur faster.

What type of reactions are exergonic?

Exergonic reactions are those that release energy, such as cellular respiration.

What is the induced fit model of enzymes?

The induced fit model suggests that an enzyme slightly changes shape to better align with the substrate.

What happens to enzymes at high temperatures?

High temperatures can lead to denaturation of enzymes, changing their shape and functionality.

What is the optimal pH range for enzyme activity?

Each enzyme has an optimal pH at which it functions best; deviations can slow down or halt its activity.

What is feedback inhibition in enzymatic reactions?

Feedback inhibition is a regulatory mechanism where a cell slows or stops a process to prevent waste when enough product is made.

What is the function of pigments in the light-dependent reactions of photosynthesis?

Pigments capture light energy and transform it into chemical energy during the light-dependent reactions.

What are the products of the light-dependent reactions of photosynthesis?

The light-dependent reactions produce ATP and NADPH, with oxygen as a byproduct.

What is photorespiration?

Photorespiration is a wasteful process that occurs when plants close stomata to conserve water, causing an accumulation of O2 and reduced CO2 access.

What distinguishes C4 plants from C3 plants?

C4 plants physically separate carbon fixation from the Calvin Cycle, allowing them to minimize photorespiration.

What are CAM plants?

CAM plants separate carbon fixation from the Calvin Cycle based on the time of day, fixing carbon at night.

What is glycolysis?

Glycolysis is the first step in cellular respiration where glucose is broken down to produce ATP, occurring in the cytoplasm.

What is the difference between fermentation and cellular respiration?

Fermentation occurs without oxygen and regenerates NAD+, while cellular respiration requires oxygen and produces more ATP.

What does the term 'competitive inhibitors' refer to in enzyme activity?

Competitive inhibitors are molecules that bind to the active site of an enzyme, preventing substrate binding.

How does temperature affect enzyme activity?

Increasing temperature can initially enhance reaction rates, but too high temperatures can lead to denaturation of the enzyme.

What is the significance of the 1st Law of Thermodynamics in biological processes?

The 1st Law of Thermodynamics states that energy cannot be created or destroyed, only transformed, which is crucial during energy transformations in cells.

What is a catalyst?

A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process.

What is substrate specificity in enzymes?

Substrate specificity refers to the ability of an enzyme to select only one or a few substrates from a pool of similar molecules.

What is denaturation in enzymes?

Denaturation is the process in which an enzyme loses its functional shape, often due to high temperature or extreme pH.

What is the function of cofactors in enzyme activity?

Cofactors are non-protein chemical compounds that are required for the biological activity of some enzymes.

What is allosteric regulation?

Allosteric regulation occurs when a molecule binds to an enzyme at a site other than the active site, altering its activity.

What is the difference between anabolic and catabolic pathways?

Anabolic pathways build complex molecules from simpler ones, while catabolic pathways break down molecules to release energy.

What role do ribozymes play in biological processes?

Ribozymes are RNA molecules that can catalyze specific biochemical reactions, similar to the way enzymes do.

What is the significance of the active site in enzymes?

The active site is the region on an enzyme where substrate molecules bind and undergo a chemical reaction.

What is the role of feedback inhibition in metabolic processes?

Feedback inhibition helps regulate the production of substances in a metabolic pathway by inhibiting an earlier step when enough product is made.

How do environmental factors influence enzyme activity?

Environmental factors such as temperature, pH, and substrate concentration can significantly affect the rate of enzyme-catalyzed reactions.

What is the primary function of enzymes in cells?

The primary function of enzymes in cells is to speed up biochemical reactions by lowering the activation energy.

What do enzymes require for optimal activity?

Enzymes require specific temperature and pH ranges for optimal activity.

What is a substrate in enzyme reactions?

A substrate is a molecule upon which an enzyme acts.

What happens to the substrate when it binds to an enzyme?

When the substrate binds to an enzyme, it forms an enzyme-substrate complex, facilitating the reaction.

What is the term for a molecule that permanently alters enzyme activity?

A permanent alteration in enzyme activity is referred to as irreversible inhibition.

What distinguishes competitive inhibitors from non-competitive inhibitors?

Competitive inhibitors bind to the active site of an enzyme, while non-competitive inhibitors bind to another site, changing the enzyme's shape.

How does pH affect enzyme activity?

Extreme pH levels can denature enzymes, altering their shape and function.

What is the role of coenzymes in enzymatic reactions?

Coenzymes are organic molecules that assist enzymes in catalyzing reactions.

Give an example of a coenzyme.

NAD+ (Nicotinamide adenine dinucleotide) is a common coenzyme involved in redox reactions.

What is the significance of enzyme concentration on reaction rates?

Increased enzyme concentration typically leads to an increase in reaction rates, up to a certain point.

What are allosteric enzymes?

Allosteric enzymes are enzymes whose activity is regulated by the binding of molecules at sites other than the active site.

What is the effect of enzyme inhibitors on reaction rates?

Enzyme inhibitors decrease the rate of enzymatic reactions.

What is the function of proteases?

Proteases are enzymes that catalyze the breakdown of proteins into smaller peptides or amino acids.

What is a biochemical pathway?

A biochemical pathway is a series of enzymatic reactions that lead to the conversion of a substrate into a product.

What is the purpose of a metabolic pathway?

Metabolic pathways transform substrates through a series of steps, often branching to provide various products.

What role do vitamins play in enzymatic reactions?

Some vitamins serve as precursors for coenzymes, enhancing enzyme activity.

What are lipases?

Lipases are enzymes that catalyze the hydrolysis of fats into glycerol and fatty acids.

How does temperature impact enzyme activity?

Increased temperature can speed up enzyme reactions until denaturation occurs, decreasing activity.

What is the role of amylase?

Amylase is an enzyme that catalyzes the breakdown of starch into sugars.

What effect do metal ions have on enzyme activity?

Metal ions can act as cofactors, helping to stabilize enzyme structure and function.

How are enzymes regulated in metabolic pathways?

Enzymes are regulated through feedback inhibition and allosteric regulation to maintain cellular homeostasis.

What are hydrolases?

Hydrolases are enzymes that catalyze the hydrolysis of chemical bonds.

What is the importance of enzyme specificity?

Enzyme specificity ensures that enzymes catalyze only specific reactions, preventing unwanted reactions in cells.

What is the main difference between aerobic and anaerobic respiration in terms of energy production?

Aerobic respiration requires oxygen and produces more ATP compared to anaerobic respiration, which occurs without oxygen.

What are the end products of yeast fermentation?

The end products of yeast fermentation include ethanol and carbon dioxide.

Why is feedback inhibition important in metabolic pathways?

Feedback inhibition prevents overproduction of substances and conserves cellular resources.

What is a common method for measuring enzyme activity?

Measuring the rate of substrate conversion to product is a common method for assessing enzyme activity.

What is the significance of the active site shape?

The active site shape is crucial for substrate binding, as it determines the specificity of the enzyme.

How do environmental changes affect enzyme denaturation?

Environmental changes such as extreme temperature or pH can cause denaturation, affecting enzyme functionality.

What is the role of enzymes in DNA replication?

Enzymes such as DNA polymerases are essential for synthesizing new DNA strands during replication.

What is the significance of enzyme saturation?

Enzyme saturation occurs when all active sites are occupied, leading to a maximum reaction rate.

Fill in the blank: Enzymes are __________ that catalyze biochemical reactions.

catalysts

Fill in the blank: The __________ site is the specific region on an enzyme where substrate binding occurs.

active

Fill in the blank: Enzymes work by lowering the __________ required for a reaction.

activation energy

Fill in the blank: The __________ fit model describes how enzymes adjust their shape upon substrate binding.

induced

Fill in the blank: __________ inhibitors compete with substrates for the active site of an enzyme.

Competitive

Fill in the blank: __________ inhibitors bind to an enzyme at a different location than the active site, altering its shape.

Non-competitive

Fill in the blank: An enzyme's __________ is affected by temperature, pH, and the concentration of substrates.

activity

Fill in the blank: Enzyme denaturation can occur due to extreme __________ levels.

pH

Fill in the blank: __________ is the process through which an enzyme loses its functional shape.

Denaturation

Fill in the blank: Cofactors are often __________ that assist enzymes in their catalytic activity.

metal ions

Fill in the blank: __________ enzymes have their activity regulated by molecules binding at sites other than the active site.

Allosteric

Fill in the blank: The __________ Law of Thermodynamics states that energy cannot be created or destroyed.

1st

Fill in the blank: The conversion of glucose into pyruvate occurs during the process of __________.

glycolysis

Fill in the blank: Stomata closure in plants can lead to a process called __________, which reduces photosynthesis efficiency.

photorespiration

Fill in the blank: CAM plants fix carbon at __________ to minimize water loss.

night

Fill in the blank: __________ respiration occurs in the presence of oxygen and produces ATP efficiently.

Aerobic

Fill in the blank: The end products of anaerobic fermentation in yeast are __________ and carbon dioxide.

ethanol

Fill in the blank: __________ concentration can increase the rate of enzyme-catalyzed reactions up to a saturation point.

Enzyme

Fill in the blank: __________ are enzymes that break down proteins into smaller peptides or amino acids.

Proteases

Fill in the blank: Metabolic pathways transform substrates through a series of __________ reactions.

enzymatic

Fill in the blank: __________ are organic molecules that assist enzymes, often derived from vitamins.

Coenzymes

Fill in the blank: The __________ of an enzyme is crucial for its ability to bind substrates effectively.

shape

Fill in the blank: __________ reactions release energy, typically seen during cellular respiration.

Exergonic

Fill in the blank: __________ energy is the initial energy needed to start a chemical reaction.

Activation

Fill in the blank: Enzymes are essential for the __________ of DNA molecules during replication.

synthesis

Fill in the blank: Feedback inhibition is a regulatory mechanism that prevents __________ production by inhibiting an earlier step.

excess

Fill in the blank: __________ examples include NAD+ and FAD, which are involved in redox reactions in metabolism.

Coenzymes

Fill in the blank: Enzyme __________ occurs when all active sites are occupied, reaching a maximum reaction rate.

saturation

Fill in the blank: __________ in metabolic pathways helps maintain cellular homeostasis by regulating enzyme activity.

Feedback inhibition

Fill in the blank: The process of converting starch into sugars is catalyzed by the enzyme __________.

amylase

Fill in the blank: __________ enzymes are those that catalyze the hydrolysis of chemical bonds by adding water.

Hydrolases

Fill in the blank: The __________ specificity of enzymes ensures that they only react with particular substrates.

substrate