9/14/26, 11:22 AM NU 545 Unit 1 Flashcards | Quizlet
Cell membranes contain which major chemical "The main components of cell membranes are lipids and proteins. The basic structure
components? of cell membranes is the lipid bilayer..." pg 12
What allows potassium to diffuse in and out of cells? 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? Plasma membrane pg 12 table 1.1 (functions of membrane).
In cirrhosis, what does cholesterol have to do with the causes a decrease in membrane fluidity and affects the cells' ability to transport
erythrocytes? oxygen
What is platelet-derived growth factor? 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? 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.
https://quizlet.com/819664678/nu-545-unit-1-flash-cards/ 3/27
,9/14/26, 11:22 AM NU 545 Unit 1 Flashcards | Quizlet
What is chemical signaling? 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? Pancreatic cells secrete and release insulin to signal muscle cells to absorb sugar
from the blood for energy. (p.3)
https://quizlet.com/819664678/nu-545-unit-1-flash-cards/ 4/27
, 9/14/26, 11:22 AM NU 545 Unit 1 Flashcards | Quizlet
Understand the transportation of potassium and sodium The Na+ -K+ antiport system (Na+ moving out of the cell and K+ moving into the cell)
across plasma membranes 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? 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? 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? No. For example, most of the neurons and skeletal muscle cells are in a terminally
differentiated G0 state; with their cell cycle control system disassembled, the
molecular regulatory switches become permanently turned off and cell division
rarely occurs (p. 37)
https://quizlet.com/819664678/nu-545-unit-1-flash-cards/ 5/27
Cell membranes contain which major chemical "The main components of cell membranes are lipids and proteins. The basic structure
components? of cell membranes is the lipid bilayer..." pg 12
What allows potassium to diffuse in and out of cells? 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? Plasma membrane pg 12 table 1.1 (functions of membrane).
In cirrhosis, what does cholesterol have to do with the causes a decrease in membrane fluidity and affects the cells' ability to transport
erythrocytes? oxygen
What is platelet-derived growth factor? 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? 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.
https://quizlet.com/819664678/nu-545-unit-1-flash-cards/ 3/27
,9/14/26, 11:22 AM NU 545 Unit 1 Flashcards | Quizlet
What is chemical signaling? 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? Pancreatic cells secrete and release insulin to signal muscle cells to absorb sugar
from the blood for energy. (p.3)
https://quizlet.com/819664678/nu-545-unit-1-flash-cards/ 4/27
, 9/14/26, 11:22 AM NU 545 Unit 1 Flashcards | Quizlet
Understand the transportation of potassium and sodium The Na+ -K+ antiport system (Na+ moving out of the cell and K+ moving into the cell)
across plasma membranes 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? 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? 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? No. For example, most of the neurons and skeletal muscle cells are in a terminally
differentiated G0 state; with their cell cycle control system disassembled, the
molecular regulatory switches become permanently turned off and cell division
rarely occurs (p. 37)
https://quizlet.com/819664678/nu-545-unit-1-flash-cards/ 5/27
