Energy Flow in the Biosphere

These flashcards cover key terms and concepts related to energy flow, metabolism, and body composition based on the lecture notes.

Energy Flow

The transfer of energy through various forms in an ecosystem.

Biosphere

All living organisms on Earth and their environments.

Autotrophs

Organisms that produce their own food from inorganic sources, primarily through photosynthesis.

Heterotrophs

Organisms that cannot produce their own food and obtain energy by consuming organic material.

Energy Pyramid

A graphical representation of the energy flow in an ecosystem.

Kinetic Energy

The energy associated with the motion of an object.

Potential Energy

Stored energy that has the potential to do work.

Mechanical Energy

Energy possessed by an object due to its motion or position.

Electrical Energy

Energy resulting from the movement of charged particles.

Radiant Energy

Energy of electromagnetic waves, including light.

Sound Energy

Energy produced by vibrating sound waves.

Thermal Energy

Energy related to the temperature of an object, associated with the motion of particles.

Chemical Energy

Energy stored in the bonds of chemical compounds.

Nuclear Energy

Energy stored in the nucleus of an atom.

Gravitational Energy

Potential energy related to an object's height in a gravitational field.

Elastic Energy

Potential energy stored in elastic materials as the result of their stretching or compressing.

Catabolism

The metabolic process of breaking down molecules to produce energy.

Cellular Respiration

The process by which cells convert glucose into energy (ATP) using oxygen.

ATP (Adenosine Triphosphate)

The primary energy carrier in cells.

Glycolysis

The first step of cellular respiration, breaking glucose down into pyruvate.

Krebs Cycle

A series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetyl CoA.

Electron Transport Chain

A series of complexes that transfer electrons through a membrane within mitochondria to generate ATP.

NADH

A coenzyme that carries electrons from one reaction to another in cellular respiration.

Acetyl CoA

A central molecule in metabolism, derived from carbohydrates and fats.

Glycerol

The three-carbon molecule that forms the backbone of lipids.

Fatty Acids

Carboxylic acids with long aliphatic chains, fundamental components of lipids.

Amino Acids

Organic compounds that serve as the building blocks of proteins.

Gluconeogenesis

The metabolic process by which glucose is generated from non-carbohydrate substrates.

Lactate

A byproduct of anaerobic metabolism that can be converted back to glucose in the liver.

Oxaloacetate

A four-carbon molecule that plays a critical role in the TCA cycle.

Cori Cycle

The metabolic pathway where lactate is converted back to glucose in the liver.

Atwater system

A method for estimating caloric values of food based on macronutrient composition.

4-9-4 method

Caloric estimation method: 4 kcal/g for carbohydrates and proteins, 9 kcal/g for fats.

Hydrocabon Chains

Chains of carbon and hydrogen atoms, commonly found in fats and oils.

Calorimetry

The science of measuring the heat absorbed or released during a chemical reaction.

Energy Density

The amount of energy a food contains in relation to its weight.

Body Composition

The percentages of fat, bone, water, and muscle in human bodies.

BMI (Body Mass Index)

A measure of body fat based on height and weight.

Bioelectrical Impedance

A technique for estimating body composition by measuring resistance to electrical current.

Hydrodensitometry

A method for measuring body composition based on water displacement.

Dual-energy X-ray absorptiometry (DEXA)

A technique for measuring body composition using low-dose X-rays.

Physical Activity Level (PAL)

An estimate of daily physical activity that can be used to assess energy expenditure.

Total Daily Energy Expenditure (TDEE)

The total number of calories burned in a day.

Coronary Artery Disease

A condition caused by the build-up of plaque in the heart's arteries.

Central Obesity

Excess fat around the stomach and abdomen, considered a risk factor for various diseases.

Essential Fat

The necessary fat required for the body to function properly.

Energy Flow

The transfer of energy through various forms in an ecosystem.

Biosphere

All living organisms on Earth and their environments.

Autotrophs

Organisms that produce their own food from inorganic sources, primarily through photosynthesis.

Heterotrophs

Organisms that cannot produce their own food and obtain energy by consuming organic material.

Energy Pyramid

A graphical representation of the energy flow within an ecosystem, typically depicting trophic levels. Producers form the wide base, containing the most energy. At each successive level (primary consumers, secondary consumers, etc.), the available energy significantly decreases, often following the 10% rule, primarily due to metabolic processes and heat loss. This results in the characteristic pyramidal shape.

Kinetic Energy

The energy associated with the motion of an object.

Potential Energy

Stored energy that has the potential to do work.

Mechanical Energy

Energy possessed by an object due to its motion or position.

Electrical Energy

Energy resulting from the movement of charged particles.

Radiant Energy

Energy of electromagnetic waves, including light.

Sound Energy

Energy produced by vibrating sound waves.

Thermal Energy

Energy related to the temperature of an object, associated with the motion of particles.

Chemical Energy

Energy stored in the bonds of chemical compounds.

Nuclear Energy

Energy stored in the nucleus of an atom.

Gravitational Energy

Potential energy related to an object's height in a gravitational field.

Elastic Energy

Potential energy stored in elastic materials as the result of their stretching or compressing.

Catabolism

The metabolic process of breaking down molecules to produce energy.

Cellular Respiration

The process by which cells convert glucose into energy (ATP) using oxygen.

ATP (Adenosine Triphosphate)

The primary energy carrier in cells.

Glycolysis

The first step of cellular respiration, breaking glucose down into pyruvate.

Krebs Cycle

A series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetyl CoA.

Electron Transport Chain

A series of complexes that transfer electrons through a membrane within mitochondria to generate ATP.

NADH

A coenzyme that carries electrons from one reaction to another in cellular respiration.

Acetyl CoA

A central molecule in metabolism, derived from carbohydrates and fats.

Glycerol

The three-carbon molecule that forms the backbone of lipids.

Fatty Acids

Carboxylic acids with long aliphatic chains, fundamental components of lipids.

Amino Acids

Organic compounds that serve as the building blocks of proteins.

Gluconeogenesis

The metabolic process by which glucose is generated from non-carbohydrate substrates.

Lactate

A byproduct of anaerobic metabolism that can be converted back to glucose in the liver.

Oxaloacetate

A four-carbon molecule that plays a critical role in the TCA cycle.

Cori Cycle

The metabolic pathway where lactate is converted back to glucose in the liver.

Atwater system

A method for estimating caloric values of food based on macronutrient composition.

4-9-4 method

Caloric estimation method: 4 kcal/g for carbohydrates and proteins, 9 kcal/g for fats.

Hydrocabon Chains

Chains of carbon and hydrogen atoms, commonly found in fats and oils.

Calorimetry

The science of measuring the heat absorbed or released during a chemical reaction.

Energy Density

The amount of energy a food contains in relation to its weight.

Body Composition

The percentages of fat, bone, water, and muscle in human bodies.

BMI (Body Mass Index)

A measure of body fat based on height and weight.

Bioelectrical Impedance

A technique for estimating body composition by measuring resistance to electrical current.

Hydrodensitometry

A method for measuring body composition based on water displacement.

Dual-energy X-ray absorptiometry (DEXA)

A technique for measuring body composition using low-dose X-rays.

Physical Activity Level (PAL)

An estimate of daily physical activity that can be used to assess energy expenditure.

Total Daily Energy Expenditure (TDEE)

The total number of calories burned in a day.

Coronary Artery Disease

A condition caused by the build-up of plaque in the heart's arteries.

Central Obesity

Excess fat around the stomach and abdomen, considered a risk factor for various diseases.

Essential Fat

The necessary fat required for the body to function properly.

Storage Fat

Fat that accumulates under the skin and around organs, serving as an energy reserve.

Visceral Fat

Fat stored deeper within the abdominal cavity, surrounding organs like the liver and intestines, often associated with higher health risks.

Subcutaneous Fat

Fat stored directly beneath the skin, often considered less metabolically harmful than visceral fat.

Metabolic Syndrome

A cluster of conditions (increased blood pressure, high blood sugar, excess body fat around the waist, abnormal cholesterol levels) that occur together, increasing the risk of heart disease, stroke, and type 2 diabetes.

Basal Metabolic Rate (BMR)

The minimum number of calories required to keep your body functioning at rest.

Non-exercise Activity Thermogenesis (NEAT)

The energy expended for everything we do that is not sleeping, eating, or sports-like exercise; includes activities like walking to work, typing, and fidgeting.

Thermic Effect of Food (TEF)

The energy required to digest, absorb, and dispose of ingested nutrients.