Bioninja Notes - Metabolism

Metabolic reactions

Chemical processes in cells that produce energy and synthesize compounds, categorized as anabolic or catabolic.

Endergonic process

A type of reaction that absorbs energy from the environment, such as photosynthesis.

Exergonic process

A reaction that releases energy, typically associated with catabolic processes like cellular respiration.

Activation energy

The minimum energy required for a chemical reaction to occur, which enzymes help to lower.

Enzyme-substrate complex

The temporary complex formed when an enzyme binds to its substrate.

Induced fit model

The model describing how an enzyme changes shape to facilitate substrate binding.

Brownian motion

The random movement of particles in a fluid, which helps to facilitate enzyme-substrate collisions.

Optimal pH

The specific pH range at which an enzyme exhibits maximum activity.

Bell-shaped activity curve

Graphical representation showing how enzyme activity varies with pH or temperature, peaking at optimal conditions.

Reversible denaturation

A condition where some enzymes can regain functionality after returning to optimal conditions post-denaturation.

Saturation point

The stage where all enzyme active sites are occupied, resulting in maximum reaction rate.

Kinetic motion

The movement of particles that can influence the rate of enzyme-catalyzed reactions.

Homeostasis

The process by which living organisms regulate their internal environment, affecting enzyme function.

Anabolism

The process in which smaller compounds are combined to form larger compounds, often involving condensation and releasing water.

Catabolism

The process where large compounds are broken down into smaller compounds, typically requiring hydrolysis and water as an input.

Photosynthesis

An anabolic reaction that synthesizes organic compounds from inorganic sources using light energy, classified as an endergonic process.

Cellular respiration

A catabolic reaction that releases chemical energy (ATP) by breaking down organic compounds, classified as an exergonic process.

Enzymatic specificity

The ability of an enzyme to only bind to specific substrates due to the shape and chemical properties of its active site.

Lock and key model

A model describing how an enzyme's active site precisely fits one specific substrate.

Induced fit model

A model explaining how the enzyme modifies its shape upon substrate binding to enhance reactivity and lower activation energy.

Kinetic energy

The energy possessed by particles in motion, which influences the rate of enzyme-catalyzed reactions.

Denaturation

The process by which an enzyme loses its biological activity due to alterations in its shape, often caused by extreme temperature or pH conditions.

Reversible denaturation

A condition under which some enzymes can regain functionality when returned to optimal conditions after denaturation.

Bell-shaped activity curve

A representation of an enzyme's activity varying with temperature or pH, peaking at optimal conditions.

Optimal temperature

The temperature range at which an enzyme exhibits maximum activity before denaturation occurs.

Optimal pH

The specific pH range at which an enzyme's activity is at its highest, with outside ranges leading to decreased function.

Substrate saturation

The condition in which all enzyme active sites are occupied, resulting in a maximum reaction rate with no further increase in activity.

Industrial enzymes

Enzymes utilized in significant quantities for various industrial applications due to their catalytic properties.

Chemical energy

Energy stored in the bonds of chemical compounds, crucial for metabolic reactions that sustain life.

Biosynthesis

The process by which living organisms produce complex compounds from simpler ones, primarily through anabolic reactions.

Active transport

The movement of materials across a cell membrane against their concentration gradient, requiring energy.

Cellular metabolism

The set of life-sustaining chemical transformations within the cells, consisting of anabolic and catabolic pathways.

Loaded coenzyme

The active form of a coenzyme, capable of assisting enzymatic reactions.

Unloaded coenzyme

The inactive form of a coenzyme, similar to a discharged battery, not assisting enzymatic activity.

Energy currency

A term referring to ATP, highlighting its role as the primary energy carrier in cellular processes.

Hydrolysis of ATP

The reaction that breaks down ATP into ADP and inorganic phosphate, releasing energy for cellular activities.

Autotrophs

Organisms that produce their own food from inorganic substances, using light or chemical energy.

Carbohydrates (in respiration)

Organic compounds like glucose that are primarily utilized in cellular respiration to generate ATP.

Triglycerides (in respiration)

Fats that yield more energy per gram than carbohydrates, used for energy but harder to transport.

Nitrogenous by-products

Waste products generated from protein metabolism that can be toxic if not excreted.

Bank analogy of metabolism

Describes organic compounds as energy stores, while ATP represents usable currency in energy transactions.

Anaerobic respiration

A type of respiration that does not require oxygen, yielding low ATP from the partial breakdown of glucose.

Glycolysis

The first stage of both aerobic and anaerobic respiration, where glucose is broken down to produce ATP.

Fermentation

The metabolic process that converts glucose into lactic acid or alcohol and CO2 under anaerobic conditions.

Lactic acid

The by-product of anaerobic respiration in animals, produced when glucose is partially broken down.

Ethanol

An alcohol produced from the fermentation of sugars in plants and yeast during anaerobic respiration.

Aerobic respiration

A process that uses oxygen to completely break down glucose, producing a large yield of ATP.

Krebs cycle

A series of enzymatic reactions in the mitochondrial matriz, crucial for aerobic respiration.

Electron transport chain (ETC)

The final stage of aerobic respiration where ATP is generated through oxidative phosphorylation.

Mitochondrion

An organelle where aerobic respiration occurs; it has a double membrane and is involved in ATP production.

Endosymbiosis theory

The hypothesis that mitochondria originated from aerobic bacteria engulfed by early eukaryotic cells.

Cristae

Folds of the mitochondrial inner membrane that increase surface area for ATP production.

Respiration rate

The rate at which respiration occurs, measured by input consumption (glucose, oxygen) or output formation (CO2).

Temperature effect on respiration

Environmental temperature can influence the rate of respiration by affecting enzyme activity.

pH effect on respiration

The acidity or alkalinity of the environment can alter enzyme functionality, impacting respiration rates.

Glucose concentration

The availability of glucose, which serves as a substrate for aerobic and anaerobic respiration.

Oxygen availability

The amount of oxygen present, crucial for aerobic respiration and affecting respiratory efficiency.

What is photosynthesis?

Photosynthesis is the process by which cells synthesize organic compounds from inorganic molecules in the presence of sunlight.

Where does photosynthesis occur in plants?

In plants, photosynthesis occurs within the chloroplast.

What is chlorophyll?

Chlorophyll is the primary photosynthetic pigment found in plants, responsible for absorbing light.

What are pigments in photosynthesis?

Pigments are specific molecules that absorb light at specific wavelengths, facilitating energy conversion in photosynthetic organisms.

What is the role of the photosystem?

Photosystems optimize light absorption by clustering multiple pigments to maximize energy capture.

What is chromatography?

Chromatography is an experimental technique used to separate pigments based on their movement through a stationary phase.

What is the Rf value in chromatography?

The Rf value is calculated as the distance the pigment travels divided by the distance the solvent travels, used to identify pigments.

What is the visible spectrum?

The visible spectrum consists of wavelengths of light (400-700 nm) that photosynthetic organisms absorb for photosynthesis.

Which colors of light does chlorophyll absorb most effectively?

Chlorophyll absorbs red and blue light most effectively, while green light is reflected.

What happens during light-dependent reactions?

Light-dependent reactions convert light energy into chemical energy (ATP) and produce oxygen by photolysis of water.

Where do light-dependent reactions take place?

Light-dependent reactions occur in the thylakoids of the chloroplast.

What is produced as a by-product of light-dependent reactions?

Oxygen gas is produced as a waste product during light-dependent reactions.

What is the Calvin cycle?

The Calvin cycle, or light-independent reactions, synthesizes organic compounds using ATP and carbon dioxide.

What is the main enzyme involved in the Calvin cycle?

The main enzyme involved in the Calvin cycle is Rubisco, which catalyzes carbon fixation.

What are the main inputs of the Calvin cycle?

The main inputs of the Calvin cycle are carbon dioxide, ATP, and hydrogen.

What is the product of the Calvin cycle?

The main product of the Calvin cycle is glucose.

How is photosynthesis measured by oxygen production?

Oxygen production can be measured by the rate of bubble formation or pressure change in an enclosed container.

How can carbon dioxide uptake be measured?

Carbon dioxide uptake can be measured by observing pH changes in a solution due to carbonic acid formation.

What does biomass indicate in measuring photosynthesis?

Biomass, or the total dry weight of an organism, indicates the amount of organic compounds produced through photosynthesis.

What are limiting factors in photosynthesis?

Limiting factors are conditions that limit the rate of photosynthesis when they are nearest to their minimum values, such as temperature, light, and carbon dioxide.

What is meant by carbon enrichment experiments?

Carbon enrichment experiments study the effects of increased carbon dioxide levels on plant growth and photosynthesis.

What impacts can high carbon dioxide levels have on plants?

High carbon dioxide levels can enhance plant growth but may also cause damage in excessive concentrations.

What is free air carbon dioxide enrichment (FACE)?

FACE is a method used to study the effects of increased carbon dioxide levels in natural conditions.

What is photolysis in photosynthesis?

Photolysis is the process where water molecules are broken down by light energy, producing oxygen and hydrogen.

What is the stroma?

The stroma is the fluid-filled region within chloroplasts where light-independent reactions (Calvin cycle) occur.

What is the primary purpose of light-independent reactions?

The primary purpose of light-independent reactions is to synthesize organic compounds from carbon dioxide using ATP and hydrogen.

What factors influence the rate of photosynthesis?

Factors influencing the rate of photosynthesis include light intensity, carbon dioxide concentration, and temperature.

Why is green light reflected by plants?

Green light is reflected by plants because it is too energetic for efficient use in photosynthesis.

What is an absorption spectrum?

An absorption spectrum shows the amount of light absorbed by pigments at different wavelengths.

What is an action spectrum?

An action spectrum indicates the rate of photosynthesis at different wavelengths of light.

How do temperature changes affect photosynthesis?

Temperature changes can affect enzyme activity and metabolic processes, influencing the rate of photosynthesis.

What organelle is primarily involved in photosynthesis?

The chloroplast is the organelle primarily involved in photosynthesis.

How does light intensity impact photosynthesis?

Higher light intensity can increase the rate of photosynthesis up to a certain point, beyond which other factors may limit the process.

What role do thylakoids play in photosynthesis?

Thylakoids are membrane-bound structures in chloroplasts where light-dependent reactions occur.

Metabolic pathways

Series of chemical reactions in a cell, each controlled by a specific enzyme; can be intracellular or extracellular.

Intracellular reactions

Reactions that occur within a cell, such as glycolysis and Krebs cycle.

Extracellular reactions

Reactions occurring outside the cell, such as nutrient breakdown in the gut.

Linear chains

Straight sequences of enzyme-catalyzed reactions, exemplified by glycolysis.

Cyclic pathways

Enzyme-catalyzed reactions arranged in a cycle, such as the Krebs cycle and Calvin cycle.

Reactivity control

Metabolic pathways provide regulatory control through multiple intermediates.

Energy transfer efficiency

Metabolic reactions are not 100% efficient; energy is often lost as heat.

Endotherms

Animals, like mammals and birds, that generate heat to maintain a constant body temperature.

Torpor

State some animals enter to reduce metabolic activity and conserve heat.