BI101 Energy and Nutrition

Why do living organisms require energy?

Living organisms require energy to perform essential cellular and life processes such as growth, reproduction, and maintaining homeostasis.

What cellular and life processes require energy?

Processes include cellular respiration, muscle contraction, nerve impulse transmission, and biosynthesis of molecules.

What is the energy law in relation to life?

The energy law, or the first law of thermodynamics, states that energy cannot be created or destroyed, only transformed from one form to another.

What are the different types of energy related to cell functions?

Types of energy include potential energy, kinetic energy, and thermal energy, each playing a role in cellular activities.

How is energy lost and utilized by cells?

Cells utilize energy through metabolic processes, and energy is lost as heat during these transformations.

How is potential energy across a membrane captured?

Potential energy across a membrane is captured through processes like chemiosmosis, where it drives ATP synthesis.

What is the importance of chemical energy?

Chemical energy is crucial as it is stored in organic molecules and is released during metabolic reactions to fuel cellular activities.

Where is the energy of an organic molecule stored?

The energy of an organic molecule is stored in the chemical bonds between atoms.

How are energy, ATP, and entropy related to cell function?

Energy is stored in ATP, which cells use for work, while entropy increases as energy is transformed, reflecting the second law of thermodynamics.

What is the flow of energy in living organisms?

Energy flows from the sun to plants (producers), then to animals (consumers), and finally to decomposers, forming a food chain.

Why do living organisms require organic nutrients?

Organic nutrients provide essential building blocks for growth, energy, and metabolic processes.

How do organic molecules provide energy to living organisms?

Organic molecules provide energy through their breakdown during cellular respiration, releasing stored chemical energy.

What does 'organic' mean in chemistry?

In chemistry, 'organic' refers to compounds primarily made of carbon atoms, often containing hydrogen, oxygen, and other elements.

What properties of carbon make it unique?

Carbon's ability to form four covalent bonds allows for diverse structures and complex molecules, making it essential for life.

How do functional groups impact the function of a molecule?

Functional groups determine the chemical properties and reactivity of organic molecules, influencing their roles in biological systems.

What is the difference between monomers and polymers?

Monomers are single units that can join to form polymers, which are larger, complex molecules made of repeating monomer units.

What do the prefixes mono- and poly- mean?

Mono- means one, while poly- means many, indicating the number of repeating units in molecules.

What is dehydration synthesis?

Dehydration synthesis is a reaction that combines monomers into polymers by removing a water molecule.

What is hydrolytic reaction?

A hydrolytic reaction breaks down polymers into monomers by adding water.

What is the role of carbohydrates in living organisms?

Carbohydrates provide energy, serve as structural components, and are involved in cell recognition processes.

How do simple sugars provide energy to cells?

Simple sugars are quickly metabolized to produce ATP, the energy currency of the cell.

What are the roles of lipids in living organisms?

Lipids store energy, form cell membranes, and serve as signaling molecules.

What are the functions of proteins within the body?

Proteins serve as enzymes, structural components, transport molecules, and play roles in immune response.

How is protein function related to its structure?

The function of a protein is determined by its specific three-dimensional structure, which is influenced by its amino acid sequence.

What are the key organs involved in processing energy nutrients?

Key organs include the mouth, stomach, small intestine, and pancreas, which work together in digestion.

What is the primary role of accessory organs in digestion?

Accessory organs, such as the liver and pancreas, produce enzymes and substances that aid in digestion.

What is an enzyme?

An enzyme is a biological catalyst that speeds up chemical reactions in the body without being consumed.

How do enzymes impact the energy required for a reaction?

Enzymes lower the activation energy needed for reactions, allowing them to occur more easily.

How are energy nutrients processed by the digestive system?

Energy nutrients are broken down into their monomer components (sugars, fatty acids, amino acids) for absorption and use by cells.

What is the role of mitochondria in a cell?

Mitochondria are the powerhouses of the cell, responsible for producing ATP through cellular respiration, converting energy from nutrients into a usable form.

How are mitochondria related to the bodily functions of eating and breathing?

Mitochondria utilize nutrients from food and oxygen from breathing to produce ATP, which powers cellular activities.

What is the endosymbiotic theory?

The endosymbiotic theory proposes that mitochondria and chloroplasts originated as free-living prokaryotes that were engulfed by ancestral eukaryotic cells, leading to a symbiotic relationship.

What are the differences between prokaryotic and eukaryotic cells?

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a defined nucleus and various organelles, including mitochondria.

How does the plasma membrane regulate the movement of materials?

The plasma membrane is selectively permeable, allowing certain molecules to pass while blocking others, thus regulating the entry and exit of substances.

What features of the plasma membrane enable it to regulate movement?

The plasma membrane is composed of a phospholipid bilayer with embedded proteins that facilitate selective transport and communication.

Why is the plasma membrane considered semipermeable?

The plasma membrane is semipermeable because it allows certain substances to pass through while restricting others based on size, charge, and solubility.

What are passive transport methods in cells?

Passive transport methods include diffusion and osmosis, where substances move across the membrane without the use of energy, following their concentration gradient.

What is active transport?

Active transport is the process that requires energy to move molecules against their concentration gradient or to transport larger molecules across the cell membrane.

How do cells move large molecules across a membrane?

Cells use processes such as endocytosis and exocytosis to move large molecules in and out of the cell.

What are the major stages in the breakdown of organic nutrients to energy?

The major stages include glycolysis, the citric acid cycle, and the electron transport chain.

What process of cell respiration occurs in the mitochondria?

The citric acid cycle occurs in the mitochondria, where acetyl-CoA is oxidized to produce ATP, NADH, and FADH2.

What is glycolysis?

Glycolysis is the first stage of cellular respiration that breaks down glucose into pyruvate, producing a small amount of ATP and NADH.

What happens to the output of glycolysis before entering the mitochondria?

The pyruvate produced in glycolysis is converted into acetyl-CoA before entering the mitochondria.

What key molecules are released during the citric acid cycle?

The citric acid cycle releases carbon dioxide, ATP, NADH, and FADH2.

Why is it important to collect electrons from glucose digestion?

Collecting electrons is crucial for the electron transport chain, where they are used to produce ATP and water.

What molecule accepts spent hydrogen electrons in the mitochondria?

Oxygen accepts the spent hydrogen electrons, forming water as a byproduct of cellular respiration.

How does the electron transport chain produce ATP?

The electron transport chain uses the energy from electrons to pump protons across the mitochondrial membrane, creating a gradient that drives ATP synthesis.

Is energy produced if only glycolysis occurs?

Yes, glycolysis produces a small amount of ATP, but without oxygen, further energy production via the citric acid cycle and electron transport chain cannot occur.

How do fats and lipids enter the aerobic pathway?

Fats and lipids are broken down into fatty acids and glycerol, which can then enter the citric acid cycle for energy production.

What is the role of vitamins in biological reactions?

Vitamins act as coenzymes that assist enzymes in catalyzing biochemical reactions, including those involved in digestion and energy production.

How do coenzymes impact biological reactions?

Coenzymes enhance the rate of reactions by assisting enzymes in their function, often by providing necessary chemical groups.

What are the physiological effects of caffeine?

Caffeine can increase alertness, enhance metabolic rate, and stimulate the central nervous system.

How does caffeine influence metabolic rate?

Caffeine can increase metabolic rate by stimulating the release of adrenaline, which enhances energy expenditure.

Do energy drinks provide cellular energy?

Energy drinks may not provide direct cellular energy but can contain stimulants that enhance alertness and perceived energy levels.