john
Physiology 335
Weeks 1-3
CHAPTER 1 (Week 1)
1. Why do cells differentiate and what are the 4 specialized cell types?
In a multicellular organism, one cell could not perform all functions necessary for
survival. Cells differentiate to perform specific functions in order to increase efficiency
and reduce energy expenditure.
4 types are: muscle, nerve, epithelial, connective
2. What fluid compartments exist within the body? What proportion of the body’s total fluid
is in each compartment?
Intracellular (ICF)
Extracellular (ECF)--interstitial (ISF) and plasma
Total fluid = 42 L
ICF= 28L = 2/3
ECF= 14L (11L ISF and 3L plasma) = 1/3
3. Explain the difference between steady state and equilibrium. Name at least one example
of each discussed in lecture.
A steady state requires energy input to maintain. Equilibrium does not require energy.
Examples:
Equilibrium—diffusion and mediated transport across cellular membrane down a
concentration gradient
Steady State—maintenance of electrochemical gradient using Na+/K+ ATP-ase pump
4. Draw a generic negative feedback control system. Come up with an example and describe
each step of the system. How does positive feedback differ?
Example: Control of body temperature, exercise and blood pressure
Positive feedback: variable accelerates further change, must have terminating event
This study source was downloaded by 100000799293039 from CourseHero.com on 10-05-2023 02:06:27 GMT -05:00
https://www.coursehero.com/file/52038893/Phys-335-outline-1-answersdocx/
, john
CHAPTER 3 (Week 1)
1. List at least three different components of a cell membrane along with their function.
Phospholipids-form selectively permeable bilayer
Cholesterol-membrane fluidity
Proteins-transport across membrane, enzyme activity, receptors, cell recognition, etc.
2. Explain the term “amphipathic”. How does this apply to cell membranes?
Amphipathic describes a molecule that is both polar and nonpolar. Phospholipids have
this character and it contributes to formation of lipid bilayer membrane. Lipid core
component largely determines permeability of membrane.
CHAPTER 4 (Week 1 & 2)
1. What are the 4 types of movement across cellular membranes? Explain the mechanism
of each and name an example for each category.
Simple diffusion-movement down concentration gradient (ex. O2, CO2, ethanol, FAs,
steroids)
Facilitated Diffusion-uses protein transporter or channel to move across membrane and
down concentration gradient (ex. ions, glucose)
Primary Active Transport-use ATP to move ions against gradient (ex. Na+/K+ ATP-ase)
Secondary Active Transport-uses gradient established by primary active transport to
move other substances against their concentration gradients (ex. Symport-AAs, glucose;
Antiport-Ca2+, H+)
2. Label each line of the diagram below with the associated type of transport. What does
the dashed line represent?
Flux into cell
[ECF]
A. Simple diffusion, B. ion channel, C. facilitated diffusion
Dashed line=max flux, saturation
This study source was downloaded by 100000799293039 from CourseHero.com on 10-05-2023 02:06:27 GMT -05:00
https://www.coursehero.com/file/52038893/Phys-335-outline-1-answersdocx/
Physiology 335
Weeks 1-3
CHAPTER 1 (Week 1)
1. Why do cells differentiate and what are the 4 specialized cell types?
In a multicellular organism, one cell could not perform all functions necessary for
survival. Cells differentiate to perform specific functions in order to increase efficiency
and reduce energy expenditure.
4 types are: muscle, nerve, epithelial, connective
2. What fluid compartments exist within the body? What proportion of the body’s total fluid
is in each compartment?
Intracellular (ICF)
Extracellular (ECF)--interstitial (ISF) and plasma
Total fluid = 42 L
ICF= 28L = 2/3
ECF= 14L (11L ISF and 3L plasma) = 1/3
3. Explain the difference between steady state and equilibrium. Name at least one example
of each discussed in lecture.
A steady state requires energy input to maintain. Equilibrium does not require energy.
Examples:
Equilibrium—diffusion and mediated transport across cellular membrane down a
concentration gradient
Steady State—maintenance of electrochemical gradient using Na+/K+ ATP-ase pump
4. Draw a generic negative feedback control system. Come up with an example and describe
each step of the system. How does positive feedback differ?
Example: Control of body temperature, exercise and blood pressure
Positive feedback: variable accelerates further change, must have terminating event
This study source was downloaded by 100000799293039 from CourseHero.com on 10-05-2023 02:06:27 GMT -05:00
https://www.coursehero.com/file/52038893/Phys-335-outline-1-answersdocx/
, john
CHAPTER 3 (Week 1)
1. List at least three different components of a cell membrane along with their function.
Phospholipids-form selectively permeable bilayer
Cholesterol-membrane fluidity
Proteins-transport across membrane, enzyme activity, receptors, cell recognition, etc.
2. Explain the term “amphipathic”. How does this apply to cell membranes?
Amphipathic describes a molecule that is both polar and nonpolar. Phospholipids have
this character and it contributes to formation of lipid bilayer membrane. Lipid core
component largely determines permeability of membrane.
CHAPTER 4 (Week 1 & 2)
1. What are the 4 types of movement across cellular membranes? Explain the mechanism
of each and name an example for each category.
Simple diffusion-movement down concentration gradient (ex. O2, CO2, ethanol, FAs,
steroids)
Facilitated Diffusion-uses protein transporter or channel to move across membrane and
down concentration gradient (ex. ions, glucose)
Primary Active Transport-use ATP to move ions against gradient (ex. Na+/K+ ATP-ase)
Secondary Active Transport-uses gradient established by primary active transport to
move other substances against their concentration gradients (ex. Symport-AAs, glucose;
Antiport-Ca2+, H+)
2. Label each line of the diagram below with the associated type of transport. What does
the dashed line represent?
Flux into cell
[ECF]
A. Simple diffusion, B. ion channel, C. facilitated diffusion
Dashed line=max flux, saturation
This study source was downloaded by 100000799293039 from CourseHero.com on 10-05-2023 02:06:27 GMT -05:00
https://www.coursehero.com/file/52038893/Phys-335-outline-1-answersdocx/
