Diffusion and Active Transport overview

Question 1

Describe the role of DNA in the cell

Answer 1

DNA contains genetic information that encodes the sequence of amino acids in a protein and serves as a permanent store of genetic information.

Question 2

Explain how RNA functions in the cell

Answer 2

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.

Question 3

Compare the structure of DNA and RNA

Answer 3

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).

Question 4

Explain the purpose of mRNA in protein synthesis

Answer 4

mRNA acts as a messenger carrying genetic information from DNA to the ribosome, where it is used to assemble a protein.

Question 5

Describe the process of DNA replication

Answer 5

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.

Question 6

Explain the role of helicase in DNA replication

Answer 6

Helicase unwinds the DNA double helix by breaking hydrogen bonds between complementary base pairs.

Question 7

What is the function of DNA polymerase in replication?

Answer 7

DNA polymerase adds complementary nucleotides to the template strand and has proofreading ability to correct mistakes.

Question 8

Describe the process of transcription

Answer 8

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.

Question 9

What happens during translation?

Answer 9

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.

Question 10

Explain the role of the Golgi Apparatus in protein processing

Answer 10

The Golgi apparatus modifies, processes, and packages proteins into vesicles for transport outside the cell via exocytosis.

Question 11

Describe the process of exocytosis

Answer 11

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.

Question 12

What is required for vesicle fusion in exocytosis?

Answer 12

Calcium ions (Ca²⁺) are required for the vesicle to fuse with the cell membrane during exocytosis.

Question 13

Explain the structure of the phospholipid bilayer

Answer 13

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.

Question 14

Describe the role of choleserol in the phospholipid bilayer

Answer 14

Cholesterol stabilizes membrane fluidity by preventing the bilayer from becoming too rigid or too fluid.

Question 15

define diffusion

Answer 15

Diffusion is the net movement of solutes from an area of high concentration to an area of low concentration, until equilibrium is reached.

Question 16

describe the process of osmosis

Answer 16

Osmosis is the movement of water through a semipermeable membrane from an area of lower solute concentration (hypotonic) to higher solute concentration (hypertonic).

Question 17

explain what happens to a cell in a hypotonic solution

Answer 17

In a hypotonic solution, water enters the cell, which may cause it to swell or burst.

Question 18

what occurs to a cell in a hypertonic solution?

Answer 18

In a hypertonic solution, water leaves the cell, causing it to shrink.

Question 19

explain active transport

Answer 19

Active transport is the movement of molecules against their concentration gradient (from low to high concentration) using energy in the form of ATP.

Question 20

describe the process of active transport

Answer 20

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.

Question 21

what is the role of sodium-potassium pumps in active transport?

Answer 21

Sodium-potassium pumps move sodium (Na⁺) out of the cell and potassium (K⁺) into the cell, maintaining proper ion balance and cellular functions.

Question 22

explain facilitated diffusion

Answer 22

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.

Question 23

describe the difference between channel proteins and carrier proteins in facilitated diffusion

Answer 23

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.

Question 24

explain the role of DNA in protein synthesis and health

Answer 24

DNA stores genetic information and provides instructions for protein synthesis, which is essential for cellular function, growth, and repair in the body.

Question 25

describe how RNA contributes to cellular functions in the human body

Answer 25

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.

Question 26

How do enzymes, such as helicase and DNA polymerase contribute to health?

Answer 26

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.

Question 27

explain the importance of protein synthesis in tissue repair and health

Answer 27

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.

Question 28

how does exocytosis relate to the release of hormones?

Answer 28

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.

Question 29

explain the role of exocytosis in the immune response

Answer 29

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.

Question 30

why is the phospholipid bilayer crucial for cellular function in health?

Answer 30

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.

Question 31

describe the role of cholesterol in the phospholipid bilayer and its impact on health

Answer 31

Cholesterol in the cell membrane helps maintain membrane stability and fluidity. Imbalances in cholesterol levels can lead to health issues like cardiovascular disease.

Question 32

How does diffusion affect the transport of oxygen in the blood stream?

Answer 32

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.

Question 33

Explain how osmosis maintains fluid balance in the body

Answer 33

Osmosis regulates the movement of water across cell membranes, helping maintain hydration levels, blood pressure, and the balance of electrolytes in the body.

Question 34

What is the impact of osmosis on kidney function

Answer 34

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.

Question 35

Explain the role of active transport in nutrient absorption

Answer 35

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.

Question 36

How does active transport maintain proper ion balance in cells

Answer 36

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.

Question 37

How does facilitated diffusion contribute to glucose uptake in cells?

Answer 37

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.

Question 38

Explain the role of facilitated diffusion in nerve function

Answer 38

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.

Question 39

How can defects in DNA replication contribute to diseases like cancer?

Answer 39

Errors in DNA replication can lead to mutations that accumulate over time, potentially causing uncontrolled cell growth and division, which are hallmarks of cancer.

Question 40

Explain how disruptions in protein synthesis can lead to genetic disorders

Answer 40

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.

Question 41

How does a malfunction in the phospholipid bilayer affect cell function and health

Answer 41

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.

Question 42

What health conditions result from problems in exocytosis?

Answer 42

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.