NU 545 UNIT 1 WITH 100 QUESTIONS & CORRECT
ANSWERS
1. What is metabolic absorption?
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.
2. What uses oxygen to remove hydrogen atoms in an oxidative reaction?
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.
3. During cell injury, what is released that is capable of cellular autodigestion?
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.
4. Where is the genetic information contained in the cell?
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.
,5. Cell membranes contain which major chemical components? Cell
membranes consist of:
Phospholipids (forming a bilayer).
Proteins (receptors, transport channels, enzymes).
Cholesterol (stabilizing membrane fluidity).
Carbohydrates (glycolipids, glycoproteins) for signaling and protection.
6. What allows potassium to diffuse in and out of cells?
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.
7. How is the cell protected from injury?
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.
8. In cirrhosis, what does cholesterol have to do with erythrocytes?
In cirrhosis, abnormal cholesterol metabolism alters erythrocyte membranes,
reducing their flexibility and increasing fragility.
This leads to hemolysis, target cell formation, and anemia.
9. What is platelet-derived growth factor (PDGF)?
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).
10. What is cell communication, and how does it occur?
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.
11. What is chemical signaling?
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.
12. How is glucose transported from the blood to the cell? Glucose enters cells
via:
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.
13. Transportation of potassium and sodium across plasma membranes:
The sodium-potassium pump (Na+/K+ ATPase) actively moves 3 Na+ out and 2
K+ into the cell, using ATP.
Ion channels allow passive movement of Na+ and K+, maintaining resting
membrane potential and supporting cell function.
14. What is active transport?
ANSWERS
1. What is metabolic absorption?
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.
2. What uses oxygen to remove hydrogen atoms in an oxidative reaction?
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.
3. During cell injury, what is released that is capable of cellular autodigestion?
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.
4. Where is the genetic information contained in the cell?
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.
,5. Cell membranes contain which major chemical components? Cell
membranes consist of:
Phospholipids (forming a bilayer).
Proteins (receptors, transport channels, enzymes).
Cholesterol (stabilizing membrane fluidity).
Carbohydrates (glycolipids, glycoproteins) for signaling and protection.
6. What allows potassium to diffuse in and out of cells?
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.
7. How is the cell protected from injury?
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.
8. In cirrhosis, what does cholesterol have to do with erythrocytes?
In cirrhosis, abnormal cholesterol metabolism alters erythrocyte membranes,
reducing their flexibility and increasing fragility.
This leads to hemolysis, target cell formation, and anemia.
9. What is platelet-derived growth factor (PDGF)?
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).
10. What is cell communication, and how does it occur?
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.
11. What is chemical signaling?
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.
12. How is glucose transported from the blood to the cell? Glucose enters cells
via:
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.
13. Transportation of potassium and sodium across plasma membranes:
The sodium-potassium pump (Na+/K+ ATPase) actively moves 3 Na+ out and 2
K+ into the cell, using ATP.
Ion channels allow passive movement of Na+ and K+, maintaining resting
membrane potential and supporting cell function.
14. What is active transport?
