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NU 545 Unit 1 Questions and Correct
Answers/ Latest Update / Already Graded
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 can s
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.
All rights reserved © 2025/ 2026 |
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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?
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.
All rights reserved © 2025/ 2026 |
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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)
All rights reserved © 2025/ 2026 |
, Page |4
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)
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 N a+-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)
All rights reserved © 2025/ 2026 |
NU 545 Unit 1 Questions and Correct
Answers/ Latest Update / Already Graded
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 can s
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.
All rights reserved © 2025/ 2026 |
, Page |2
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?
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.
All rights reserved © 2025/ 2026 |
, Page |3
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)
All rights reserved © 2025/ 2026 |
, Page |4
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)
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 N a+-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)
All rights reserved © 2025/ 2026 |
