NU 545 Unit 1 Questions and Answers
Question 1.
1. What is metabolic absorption?
Correct Answer: Metabolic absorption is the process by which cells take in
nutrients, water, ions, and other substances from their environment to fuel
metabolism, produce energy, and maintain cellular structures. This process is
essential for sustaining cell function and responding to environmental changes.
Question 2.
2. What uses oxygen to remove hydrogen atoms in an oxidative reaction?
Correct Answer: Peroxisomes use oxygen to remove hydrogen atoms from
specific substrates, generating hydrogen peroxide (H2O2) as a byproduct.
Enzymes like catalase then break down H2O2 to prevent damage. Peroxisomes
are crucial for detoxification, fatty acid metabolism, and nerve cell myelination.
Question 3.
3. During cell injury, what is released that is capable of cellular autodigestion?
Correct Answer: Lysosomes release enzymes such as proteases, lipases, and
nucleases during cell injury. These enzymes digest cellular components, leading
to autodigestion (autolysis) and contributing to cell death if the damage
persists.
Question 4.
4. Where is the genetic information contained in the cell?
Correct Answer: Genetic information is stored in the nucleus, which houses DNA
and histones that regulate gene activity. A small amount of DNA is also found in
mitochondria, essential for mitochondrial function and energy production.
Question 5.
5. Cell membranes contain which major chemical components? Cell membranes consist of:
Correct Answer: Phospholipids (forming a bilayer). Proteins (receptors,
transport channels, enzymes). Cholesterol (stabilizing membrane fluidity).
Carbohydrates (glycolipids, glycoproteins) for signaling and protection.
Question 6.
6. What allows potassium to diffuse in and out of cells?
Correct Answer: Potassium channels in the cell membrane allow potassium ions
to move in and out of cells along their concentration gradient, maintaining
resting membrane potential and supporting cellular functions like nerve impulse
transmission.
, Question 7.
7. How is the cell protected from injury?
Correct Answer: Cells are protected by: Plasma membrane: Barrier against
harmful substances. Glycocalyx: Cushions and protects against damage.
Cytoskeleton: Maintains structure and absorbs mechanical stress. Antioxidants:
Neutralize free radicals. Repair mechanisms: Fix DNA and maintain membrane
integrity.
Question 8.
8. In cirrhosis, what does cholesterol have to do with erythrocytes?
Correct Answer: In cirrhosis, abnormal cholesterol metabolism alters
erythrocyte membranes, reducing their flexibility and increasing fragility. This
leads to hemolysis, target cell formation, and anemia.
Question 9.
9. What is platelet-derived growth factor (PDGF)?
Correct Answer: PDGF is a signaling protein that stimulates cell growth,
proliferation, and repair. It plays a key role in wound healing, tissue
regeneration, and angiogenesis (formation of new blood vessels).
Question 10.
10. What is cell communication, and how does it occur?
Correct Answer: Cell communication involves sending and receiving signals to
coordinate activities. It occurs through: Chemical signaling: Hormones,
neurotransmitters, cytokines. Direct contact: Gap junctions, membrane-bound
signals. Autocrine, paracrine, and endocrine mechanisms.
Question 11.
11. What is chemical signaling?
Correct Answer: Chemical signaling involves the release of molecules (e.g.,
hormones, cytokines, neurotransmitters) that bind to specific receptors on
target cells, triggering a response. It includes autocrine, paracrine, and
endocrine signaling.
Question 12.
12. How is glucose transported from the blood to the cell? Glucose enters cells via:
Correct Answer: Facilitated diffusion: Through GLUT transporters, driven by a
concentration gradient. Active transport: In the intestines/kidneys via SGLT
transporters, requiring energy. Insulin: Enhances GLUT transporter activity in
muscle and fat cells.
Question 13.
13. Transportation of potassium and sodium across plasma membranes:
Question 1.
1. What is metabolic absorption?
Correct Answer: Metabolic absorption is the process by which cells take in
nutrients, water, ions, and other substances from their environment to fuel
metabolism, produce energy, and maintain cellular structures. This process is
essential for sustaining cell function and responding to environmental changes.
Question 2.
2. What uses oxygen to remove hydrogen atoms in an oxidative reaction?
Correct Answer: Peroxisomes use oxygen to remove hydrogen atoms from
specific substrates, generating hydrogen peroxide (H2O2) as a byproduct.
Enzymes like catalase then break down H2O2 to prevent damage. Peroxisomes
are crucial for detoxification, fatty acid metabolism, and nerve cell myelination.
Question 3.
3. During cell injury, what is released that is capable of cellular autodigestion?
Correct Answer: Lysosomes release enzymes such as proteases, lipases, and
nucleases during cell injury. These enzymes digest cellular components, leading
to autodigestion (autolysis) and contributing to cell death if the damage
persists.
Question 4.
4. Where is the genetic information contained in the cell?
Correct Answer: Genetic information is stored in the nucleus, which houses DNA
and histones that regulate gene activity. A small amount of DNA is also found in
mitochondria, essential for mitochondrial function and energy production.
Question 5.
5. Cell membranes contain which major chemical components? Cell membranes consist of:
Correct Answer: Phospholipids (forming a bilayer). Proteins (receptors,
transport channels, enzymes). Cholesterol (stabilizing membrane fluidity).
Carbohydrates (glycolipids, glycoproteins) for signaling and protection.
Question 6.
6. What allows potassium to diffuse in and out of cells?
Correct Answer: Potassium channels in the cell membrane allow potassium ions
to move in and out of cells along their concentration gradient, maintaining
resting membrane potential and supporting cellular functions like nerve impulse
transmission.
, Question 7.
7. How is the cell protected from injury?
Correct Answer: Cells are protected by: Plasma membrane: Barrier against
harmful substances. Glycocalyx: Cushions and protects against damage.
Cytoskeleton: Maintains structure and absorbs mechanical stress. Antioxidants:
Neutralize free radicals. Repair mechanisms: Fix DNA and maintain membrane
integrity.
Question 8.
8. In cirrhosis, what does cholesterol have to do with erythrocytes?
Correct Answer: In cirrhosis, abnormal cholesterol metabolism alters
erythrocyte membranes, reducing their flexibility and increasing fragility. This
leads to hemolysis, target cell formation, and anemia.
Question 9.
9. What is platelet-derived growth factor (PDGF)?
Correct Answer: PDGF is a signaling protein that stimulates cell growth,
proliferation, and repair. It plays a key role in wound healing, tissue
regeneration, and angiogenesis (formation of new blood vessels).
Question 10.
10. What is cell communication, and how does it occur?
Correct Answer: Cell communication involves sending and receiving signals to
coordinate activities. It occurs through: Chemical signaling: Hormones,
neurotransmitters, cytokines. Direct contact: Gap junctions, membrane-bound
signals. Autocrine, paracrine, and endocrine mechanisms.
Question 11.
11. What is chemical signaling?
Correct Answer: Chemical signaling involves the release of molecules (e.g.,
hormones, cytokines, neurotransmitters) that bind to specific receptors on
target cells, triggering a response. It includes autocrine, paracrine, and
endocrine signaling.
Question 12.
12. How is glucose transported from the blood to the cell? Glucose enters cells via:
Correct Answer: Facilitated diffusion: Through GLUT transporters, driven by a
concentration gradient. Active transport: In the intestines/kidneys via SGLT
transporters, requiring energy. Insulin: Enhances GLUT transporter activity in
muscle and fat cells.
Question 13.
13. Transportation of potassium and sodium across plasma membranes:
