1 | Page
NU 545 Unit 1 Questions and Answers
What is metabolic absorption?
Ans: The uptake and use of nutrients and other substances from the
cells surrounds (pg. 3).
What uses oxygen to remove hydrogen atoms in an oxidative
reaction?
Ans: Peroxisomes contain enzymes to use o2 to remove H atoms. This
produces hydrogen peroixide. (pg 8)
During cell injury what is released that is capable of cellular
autodigestion?
Ans: Lysosomes aid in cellular digestion, seen as "trash cans and
recycling agents" "as cells complete their life span and die, lysosomes
digest...the debris... Lysosomes involved in this process of autodigestion
are called autolysosomes or autophagomes (pg 7-8).
Where is the genetic info contained in the cell?
Ans: The nucleus contains the Nucleolus, a small dense structure
composed of RNA, DNA, DNA protein. Pg 3.
Cell membranes contain which major chemical components?
Ans: "The main components of cell membranes are lipids and proteins.
The basic structure of cell membranes is the lipid bilayer..." pg 12
What allows potassium to diffuse in and out of cells?
Ans: Diffusion is the movement of a solute molecule from and area of
greater solute concentration to an area of lesser solute concentration.
(pg. 29). Active transport of K+ and Na+ requires a Sodium-Potassium
Pump (pg. 31).
How is the cell protected from injury?
© 2025 All rights reserved
, 2 | Page
Ans: Plasma membrane pg 12 table 1.1 (functions of membrane).
In cirrhosis, what does cholesterol have to do with the
erythrocytes?
Ans: causes a decrease in membrane fluidity and affects the cells' ability
to transport oxygen
What is platelet-derived growth factor?
Ans: PDGF stimulates proliferation of connective tissue cells and
neuroglial cells. Can help with creating blood clots. Pg 38.
What is cell communication? How does it occur?
Ans: Cells need to communicate w/ each other to maintain a stable
internal environment, or homeostasis; to regulate growth and division...
it is done by 3 main ways. 1) they display plasma membrane-bound
signaling molecules (receptors) that affect the cell itself and other cells
in direct physical contact. 2) they affect receptor proteins inside the
target cell and the signal molecule has to enter the cell to bind w/ them.
3) they form protein channels that directly coordinate the activities of
the adjacent cells. Pg 19.
What is chemical signaling?
Ans: Primary means of cell-to-cell communication. 5 forms of signaling
mediated by secreted molecules: (1) Contact-dependent signaling
requires cells to be in close membrane-membrane contact; (2) Paracrine
signaling- cells secrete local chemical mediators that are quickly
absorbed, destroyed, or immobilized; (3) Autocrine signaling- cells
produce signals that they, themselves, respond to (cancer cells); (4)
Hormonal signaling involves specialized endocrine cells that secrete
chemicals called hormones (TSH). Hormones are released by one set of
cells and travel through the tissue and through the bloodstream to
produce a response in other sets of cells; (5) Neurohormonal signaling-
hormones are released into the blood by neurosecretory neurons. (p.19)
How is glucose transported from the blood to the cell?
Ans: Pancreatic cells secrete and release insulin to signal muscle cells to
absorb sugar from the blood for energy. (p.3)
© 2025 All rights reserved
, 3 | Page
Understand the transportation of potassium and sodium across
plasma membranes
Ans: The Na+ -K+ antiport system (Na+ moving out of the cell and K+
moving into the cell) uses the direct energy of ATP to move these
cations. The transporter protein is the enzyme adenosine triphosphatase
(ATPase). Approximately 60% to 70% of the ATP synthesized by cells is
used to maintain the Na+-K+ transport system. 1, three Na+ ions bind to
sodium- binding sites on the carrier's interface. 2, at the same time, an
energy- containing adenosine triphosphate molecule produced by the
cell's mitochondria bind to the carrier. The ATP disassociates,
transferring its stored energy to the carrier. 3 and 4, the carrier then
changes shape, releases the three Na+ ions to the outside of the cell, and
attracts two potassium ions to its potassium- binding site. 5, the carrier
then returns to its original shape, releasing the two K+ ions and the
remnant of the ATP molecule to the inside of the cell. The carrier is now
ready for another pumping cycle (p.31)
What is active transport?
Ans: requires life, biologic activity, and the cell's expenditure of
metabolic energy. Unlike passive transport, active transport occurs
across only living membranes that have to drive the flow "uphill" by
coupling it to an energy source (p. 28)
What are cytokines?
Ans: Growth factor, also called cytokines, stimulate an increase in cell
mass or cell growth by promoting the synthesis of proteins and other
macromolecules and inhibiting their degradation (p. 38)
Cytokines constitute a large family of small-molecular-weight soluble
intracellular-signaling molecules that are secreted, bind to a specific cell
membrane receptors, and regulate innate or adaptive immunity; either
proinflammatory or anti-inflammatory. Majority of important cytokines
are classified as interleukins or interferons (p. 201)
Do all cells continue to replicate and divide?
© 2025 All rights reserved
NU 545 Unit 1 Questions and Answers
What is metabolic absorption?
Ans: The uptake and use of nutrients and other substances from the
cells surrounds (pg. 3).
What uses oxygen to remove hydrogen atoms in an oxidative
reaction?
Ans: Peroxisomes contain enzymes to use o2 to remove H atoms. This
produces hydrogen peroixide. (pg 8)
During cell injury what is released that is capable of cellular
autodigestion?
Ans: Lysosomes aid in cellular digestion, seen as "trash cans and
recycling agents" "as cells complete their life span and die, lysosomes
digest...the debris... Lysosomes involved in this process of autodigestion
are called autolysosomes or autophagomes (pg 7-8).
Where is the genetic info contained in the cell?
Ans: The nucleus contains the Nucleolus, a small dense structure
composed of RNA, DNA, DNA protein. Pg 3.
Cell membranes contain which major chemical components?
Ans: "The main components of cell membranes are lipids and proteins.
The basic structure of cell membranes is the lipid bilayer..." pg 12
What allows potassium to diffuse in and out of cells?
Ans: Diffusion is the movement of a solute molecule from and area of
greater solute concentration to an area of lesser solute concentration.
(pg. 29). Active transport of K+ and Na+ requires a Sodium-Potassium
Pump (pg. 31).
How is the cell protected from injury?
© 2025 All rights reserved
, 2 | Page
Ans: Plasma membrane pg 12 table 1.1 (functions of membrane).
In cirrhosis, what does cholesterol have to do with the
erythrocytes?
Ans: causes a decrease in membrane fluidity and affects the cells' ability
to transport oxygen
What is platelet-derived growth factor?
Ans: PDGF stimulates proliferation of connective tissue cells and
neuroglial cells. Can help with creating blood clots. Pg 38.
What is cell communication? How does it occur?
Ans: Cells need to communicate w/ each other to maintain a stable
internal environment, or homeostasis; to regulate growth and division...
it is done by 3 main ways. 1) they display plasma membrane-bound
signaling molecules (receptors) that affect the cell itself and other cells
in direct physical contact. 2) they affect receptor proteins inside the
target cell and the signal molecule has to enter the cell to bind w/ them.
3) they form protein channels that directly coordinate the activities of
the adjacent cells. Pg 19.
What is chemical signaling?
Ans: Primary means of cell-to-cell communication. 5 forms of signaling
mediated by secreted molecules: (1) Contact-dependent signaling
requires cells to be in close membrane-membrane contact; (2) Paracrine
signaling- cells secrete local chemical mediators that are quickly
absorbed, destroyed, or immobilized; (3) Autocrine signaling- cells
produce signals that they, themselves, respond to (cancer cells); (4)
Hormonal signaling involves specialized endocrine cells that secrete
chemicals called hormones (TSH). Hormones are released by one set of
cells and travel through the tissue and through the bloodstream to
produce a response in other sets of cells; (5) Neurohormonal signaling-
hormones are released into the blood by neurosecretory neurons. (p.19)
How is glucose transported from the blood to the cell?
Ans: Pancreatic cells secrete and release insulin to signal muscle cells to
absorb sugar from the blood for energy. (p.3)
© 2025 All rights reserved
, 3 | Page
Understand the transportation of potassium and sodium across
plasma membranes
Ans: The Na+ -K+ antiport system (Na+ moving out of the cell and K+
moving into the cell) uses the direct energy of ATP to move these
cations. The transporter protein is the enzyme adenosine triphosphatase
(ATPase). Approximately 60% to 70% of the ATP synthesized by cells is
used to maintain the Na+-K+ transport system. 1, three Na+ ions bind to
sodium- binding sites on the carrier's interface. 2, at the same time, an
energy- containing adenosine triphosphate molecule produced by the
cell's mitochondria bind to the carrier. The ATP disassociates,
transferring its stored energy to the carrier. 3 and 4, the carrier then
changes shape, releases the three Na+ ions to the outside of the cell, and
attracts two potassium ions to its potassium- binding site. 5, the carrier
then returns to its original shape, releasing the two K+ ions and the
remnant of the ATP molecule to the inside of the cell. The carrier is now
ready for another pumping cycle (p.31)
What is active transport?
Ans: requires life, biologic activity, and the cell's expenditure of
metabolic energy. Unlike passive transport, active transport occurs
across only living membranes that have to drive the flow "uphill" by
coupling it to an energy source (p. 28)
What are cytokines?
Ans: Growth factor, also called cytokines, stimulate an increase in cell
mass or cell growth by promoting the synthesis of proteins and other
macromolecules and inhibiting their degradation (p. 38)
Cytokines constitute a large family of small-molecular-weight soluble
intracellular-signaling molecules that are secreted, bind to a specific cell
membrane receptors, and regulate innate or adaptive immunity; either
proinflammatory or anti-inflammatory. Majority of important cytokines
are classified as interleukins or interferons (p. 201)
Do all cells continue to replicate and divide?
© 2025 All rights reserved
