Transport Mechanisms and Metabolism

These flashcards cover key concepts from the lecture on transport mechanisms, metabolism, and the role of cystic fibrosis in relation to bodily functions.

What is passive transport?

Transport without energy, where substances move down the concentration gradient.

What are the two types of passive transport?

Simple diffusion and facilitated diffusion.

What is active transport?

Transport that requires energy to move substances against their concentration gradient.

What is phagocytosis?

The process by which cells 'eat' larger particles or other cells.

What is pinocytosis ('Cellular Drinking')?

The cell takes in extracellular fluid containing dissolved solutes by forming small vesicles, bringing in a small amount of liquid with the target substance.

What is receptor-mediated endocytosis?

A specific type of pinocytosis where receptor proteins on the cell surface bind to particular ligands, causing the cell to internalize the signal and its cargo by forming a vesicle.

What is cystic fibrosis?

A genetic disorder affecting the regulation of salt and water in the body, leading to thick mucus buildup.

What role does Pulmozyme play in cystic fibrosis treatment?

It helps to thin and loosen the thick and sticky mucus by cutting apart extracellular DNA.

What is the difference between catabolic and anabolic pathways?

Catabolic pathways break down larger molecules into smaller ones, releasing energy, while anabolic pathways build larger molecules from smaller ones, requiring energy.

How do plants contribute to the energy cycle?

Plants convert light energy into chemical energy in the form of glucose through photosynthesis.

What is the role of the electron transport chain?

It transfers electrons derived from biomolecules to produce ATP.

What is brown fat?

A type of fat that is rich in mitochondria and helps to generate heat in the body.

What happens to energy in the body?

Energy is gradually released from food, stored for later use, and helps maintain body temperature.

What substances do plants take from the ground to create energy?

Plants absorb nutrients and water from the ground and convert light into energy through photosynthesis.

What is simple diffusion?

Direct movement of substances across the cell membrane without the help of transport proteins. Example: Small, nonpolar molecules.

What is facilitated diffusion?

Movement of substances across the cell membrane with the help of carrier proteins or channel proteins, still moving from high to low concentration. Example: Ions, glucose.

What is metabolism?

The sum of all chemical reactions that occur in an organism.

What is the primary purpose of metabolism?

To break down biomolecules (proteins, carbohydrates, lipids) to extract energy.

What is the combustion analogy for metabolism?

Similar to a combustion engine, where a carbon source (fuel) and oxygen react to produce CO_2, water, and energy.

How is the biological metabolic reaction represented?

\text{Biomolecules (CHO)} + \text{Oxygen} \rightarrow \text{Energy} + CO_2 + \text{Water}

What is the ultimate energy source for most biological systems?

Light energy from the sun.

How does energy flow through biological systems?

Energy enters as light and eventually exits as heat.

What is the symbiotic relationship between photosynthesis and cellular respiration?

Photosynthesis used by autotrophs produces oxygen and sugars that heterotrophs use for cellular respiration, which in turn produces CO_2 and water that autotrophs use for photosynthesis.

What are autotrophs?

Organisms that can produce their own food from inorganic sources, such as light energy, like plants.

What is the process autotrophs typically use to create energy?

Photosynthesis.

What are the inputs for photosynthesis?

Light energy, atmospheric CO_2, and water.

What are the outputs of photosynthesis?

Organic molecules (sugars/glucose) and oxygen.

How is the process of photosynthesis represented by an equation?

\text{Light Energy} + CO_2 + \text{Water} \rightarrow \text{Sugar} + \text{Oxygen}

What are heterotrophs?

Organisms that obtain energy by consuming other organisms or their products.

What process do heterotrophs primarily use to extract energy from organic molecules?

Cellular Respiration.

What are the inputs for cellular respiration?

Organic molecules (sugars) and oxygen.

What are the outputs of cellular respiration?

Energy (ATP), CO_2 (exhaled), and water.

How is the process of cellular respiration represented by an equation?

\text{Sugar} + \text{Oxygen} \rightarrow \text{ATP (Energy)} + CO_2 + \text{Water}

Describe the interdependence between plants and animals in the energy cycle.

Plants use the CO_2 exhaled by animals to make sugar via photosynthesis, and animals use the oxygen released by plants to break down sugar via cellular respiration, creating a vital cycle.

What are catabolic pathways?

Metabolic pathways that break down larger, complex molecules into smaller, simpler ones, releasing energy (exergonic reactions).

Give examples of catabolic pathways.

Breaking down proteins into amino acids, polysaccharides into monosaccharides, or fats into fatty acids.

What are anabolic pathways?

Metabolic pathways that synthesize larger, complex molecules from smaller, simpler ones, requiring or absorbing energy (endergonic reactions).

Give examples of anabolic pathways.

Building proteins from amino acids or synthesizing complex carbohydrates from monosaccharides.

What is Acetyl CoA (Acetyl Coenzyme A)?

The central biomolecule into which all major energy-yielding food sources are converted for metabolism.

How does Acetyl CoA act as a 'Metabolic Junction'?

Proteins, carbohydrates, and fats are all broken down and ultimately transformed into Acetyl CoA, linking their metabolic pathways.

What is the primary role of Acetyl CoA in energy production?

Acetyl CoA enters the Citric Acid Cycle where it is oxidized to harvest electrons for ATP synthesis.

What is the main function of the Citric Acid Cycle (Krebs Cycle) regarding Acetyl CoA?

Its primary job is to oxidize Acetyl CoA, meaning it removes electrons from it.

Where do the electrons extracted from Acetyl CoA in the Citric Acid Cycle go?

These extracted electrons are then transferred to the Electron Transport Chain.

How does the Electron Transport Chain use the electrons from Acetyl CoA?

The Electron Transport Chain uses the energy from these electrons to generate the majority of the cell's ATP, the primary energy currency.

Why do we oxidize food substances in metabolism?

We oxidize food substances to harvest their electrons for energy production.