Diffusion and Active Transport overview Flashcards
Protein synthesis, DNA replication, Phospholipid Bilayer, diffusion, osmosis, active transport
Describe the role of DNA in the cell
DNA contains genetic information that encodes the sequence of amino acids in a protein and serves as a permanent store of genetic information.
Explain how RNA functions in the cell
RNA acts as an intermediary, carrying instructions from DNA in the nucleus to the ribosome for protein synthesis. It is temporary and does not last long.
Compare the structure of DNA and RNA
DNA: Double helix, contains deoxyribose, bases adenine (A), guanine (G), cytosine (C), and thymine (T).
RNA: Single strand, contains ribose, bases adenine (A), guanine (G), cytosine (C), and uracil (U).
Explain the purpose of mRNA in protein synthesis
mRNA acts as a messenger carrying genetic information from DNA to the ribosome, where it is used to assemble a protein.
Describe the process of DNA replication
DNA replication involves unwinding by helicase, priming by primase, synthesis by DNA polymerase, proofreading, and joining of DNA fragments to produce two identical DNA molecules.
Explain the role of helicase in DNA replication
Helicase unwinds the DNA double helix by breaking hydrogen bonds between complementary base pairs.
What is the function of DNA polymerase in replication?
DNA polymerase adds complementary nucleotides to the template strand and has proofreading ability to correct mistakes.
Describe the process of transcription
In transcription, a DNA strand is unwound by helicase, and mRNA is synthesized using one of the DNA strands as a template. The mRNA then exits the nucleus through nuclear pores.
What happens during translation?
During translation, mRNA attaches to a ribosome, tRNA brings amino acids, and they are assembled into a polypeptide chain. The polypeptide then folds into a functional protein.
Explain the role of the Golgi Apparatus in protein processing
The Golgi apparatus modifies, processes, and packages proteins into vesicles for transport outside the cell via exocytosis.
Describe the process of exocytosis
Exocytosis involves substances being enclosed in a vesicle within the cell. The vesicle moves through the cytoplasm, fuses with the cell membrane, and releases its contents outside the cell.
What is required for vesicle fusion in exocytosis?
Calcium ions (Ca²⁺) are required for the vesicle to fuse with the cell membrane during exocytosis.
Explain the structure of the phospholipid bilayer
The phospholipid bilayer consists of hydrophilic phosphate heads and hydrophobic fatty acid tails. The bilayer is flexible and semi-permeable, regulating the movement of substances.
Describe the role of choleserol in the phospholipid bilayer
Cholesterol stabilizes membrane fluidity by preventing the bilayer from becoming too rigid or too fluid.
define diffusion
Diffusion is the net movement of solutes from an area of high concentration to an area of low concentration, until equilibrium is reached.
describe the process of osmosis
Osmosis is the movement of water through a semipermeable membrane from an area of lower solute concentration (hypotonic) to higher solute concentration (hypertonic).
explain what happens to a cell in a hypotonic solution
In a hypotonic solution, water enters the cell, which may cause it to swell or burst.
what occurs to a cell in a hypertonic solution?
In a hypertonic solution, water leaves the cell, causing it to shrink.
explain active transport
Active transport is the movement of molecules against their concentration gradient (from low to high concentration) using energy in the form of ATP.
describe the process of active transport
Active transport involves a molecule binding to a transport protein, ATP hydrolysis provides energy, the protein changes shape to move the molecule across the membrane, and the protein resets after the molecule is released.
what is the role of sodium-potassium pumps in active transport?
Sodium-potassium pumps move sodium (Na⁺) out of the cell and potassium (K⁺) into the cell, maintaining proper ion balance and cellular functions.
explain facilitated diffusion
Facilitated diffusion is the transport of molecules across the cell membrane via specific carrier or channel proteins, moving down the concentration gradient without requiring ATP.
describe the difference between channel proteins and carrier proteins in facilitated diffusion
Channel proteins form pores for specific ions or molecules to pass through, while carrier proteins bind to molecules, change shape, and transport them across the membrane.
explain the role of DNA in protein synthesis and health
DNA stores genetic information and provides instructions for protein synthesis, which is essential for cellular function, growth, and repair in the body.
describe how RNA contributes to cellular functions in the human body
RNA, particularly mRNA, carries the genetic instructions from the DNA in the nucleus to the ribosomes in the cytoplasm for protein synthesis, which is critical for cell function and overall health.
How do enzymes, such as helicase and DNA polymerase contribute to health?
Enzymes like helicase and DNA polymerase are involved in DNA replication and repair. Proper DNA replication is crucial for cell division and maintaining genetic stability, preventing diseases such as cancer.
explain the importance of protein synthesis in tissue repair and health
Protein synthesis is essential for tissue repair, immune response, and enzyme production. Without proper protein synthesis, the body would struggle to repair damaged tissues and fight infections.
how does exocytosis relate to the release of hormones?
Exocytosis is essential for the release of hormones, such as insulin from pancreatic cells. This process helps regulate bodily functions like blood sugar levels and metabolism.
explain the role of exocytosis in the immune response
Exocytosis is involved in the release of antibodies and cytokines during immune responses. Immune cells, like white blood cells, use exocytosis to secrete substances that fight infections.
why is the phospholipid bilayer crucial for cellular function in health?
The phospholipid bilayer forms the cell membrane, which controls the passage of nutrients, waste products, and signals, helping maintain homeostasis in cells and contributing to overall health.
describe the role of cholesterol in the phospholipid bilayer and its impact on health
Cholesterol in the cell membrane helps maintain membrane stability and fluidity. Imbalances in cholesterol levels can lead to health issues like cardiovascular disease.
How does diffusion affect the transport of oxygen in the blood stream?
Diffusion allows oxygen to move from areas of high concentration in the lungs to areas of low concentration in the bloodstream, which is essential for cellular respiration and energy production.
Explain how osmosis maintains fluid balance in the body
Osmosis regulates the movement of water across cell membranes, helping maintain hydration levels, blood pressure, and the balance of electrolytes in the body.
What is the impact of osmosis on kidney function
Osmosis is vital in the kidneys for reabsorbing water and maintaining fluid balance, ensuring the body does not lose excessive water or electrolytes through urine.
Explain the role of active transport in nutrient absorption
Active transport allows cells in the small intestine to absorb nutrients like glucose and amino acids against their concentration gradients, providing essential nutrients for cellular metabolism and energy.
How does active transport maintain proper ion balance in cells
Active transport helps cells maintain proper ion gradients, such as sodium and potassium ions, which are necessary for cellular functions like nerve transmission and muscle contraction.
How does facilitated diffusion contribute to glucose uptake in cells?
Facilitated diffusion allows glucose to enter cells via glucose transporters. This process is essential for providing energy to cells, especially in muscles and the brain.
Explain the role of facilitated diffusion in nerve function
Facilitated diffusion allows the movement of ions, like sodium and potassium, across nerve cell membranes, which is crucial for generating electrical impulses and transmitting nerve signals.
How can defects in DNA replication contribute to diseases like cancer?
Errors in DNA replication can lead to mutations that accumulate over time, potentially causing uncontrolled cell growth and division, which are hallmarks of cancer.
Explain how disruptions in protein synthesis can lead to genetic disorders
If protein synthesis is disrupted, the body may produce faulty or insufficient proteins, which can result in genetic disorders like cystic fibrosis or muscular dystrophy.
How does a malfunction in the phospholipid bilayer affect cell function and health
A malfunction in the phospholipid bilayer can compromise the integrity of the cell membrane, affecting nutrient and ion transport, leading to conditions like cystic fibrosis or certain autoimmune diseases.
What health conditions result from problems in exocytosis?
Problems with exocytosis can affect hormone release and immune function. For example, issues with insulin release in diabetes or neurotransmitter release in neurological disorders can be linked to exocytosis malfunctions.
