Physiol Lab Quiz 1: Labs 1&2 Flashcards
Recall all the experiments conducted for lab 01
Experiment 1&2: Water Bath Temperature (w/o ice vs w/ ice)
Experiment 3&4: Heart Rate (Active vs. Sedentary)
Experiment 5: Correlation (height & head circumference/arm span)
What are the components and sequence of a feedback loop? What do each of these components do?
1) Stimulus - a variable in the body or environment that changes
2) Sensor - detects the change in the body or environment
3) Integration Center - processes the information about the change of a set point
4) Effector - carries out the instructions set by integration center
5) Response - process/change that was done by the effector
What is a set point? What is our body’s normal temperature?
Set point: Our body’s normal homeostatic settings
EX) Body T = 37 C (98.6 F)
What is the advantage of having antagonistic effectors over those without antagonist effectors?
— These are effectors that do the opposite of one another to help fine tune and regulate the responses around the set point to maintain homeostasis
— Have much better control to regulate the body into the set point than having just negative or positive feedback loop
How are positive feedback loops different from negative feedback loops?
— Positive feedback loops: Our body will have responses that is the same as the stimulus, which will then increase whatever the stimulus may be
— Negative feedback loops: If the response of our body is opposite of the stimulus
Describe homeostasis
Homeostasis is how our body regulates itself with changes in the environment.
Name the 2 general types of effectors
Muscles and glands
How does the water bath maintain homeostasis after adding ice? (Include the components of homeostasis in this answer)
After adding the ice, which is the stimulus, the water bath maintains homeostasis as the thermometer senses a change of temperature in the water. By sensing this change, the water’s integrating center will then determine whether or not a response is necessary. The effector of the water bath continues to decrease the temperature of the water and therefore the response is that the water will now be cold.
Explain the negative feedback loop that our bodies use to maintain heart rate. Be sure to include all the components of the feedback loop in the answer (including the autonomic nervous system)
- Stimulus - increase or decrease in heart rate
- Sensor/receptor - Baroreceptors detect an increase or decrease in blood pressure
- Integrating center - Cardiac center within the medulla oblongata of the brain
— Compares it to the set point (60-100 bpm) - Effector - heart
— If stimulus is too slow, nerves will send signals (norepinephrine) to heart
— If stimulus is too fast , nerves will send signals (ACh) to the heart - Response - heart will beat faster (norepinephrine) or heart will beat slower (ACh)
Calculate mean/average and range
Mean/average: adding up all the samples and then divide it by the number of samples there are
Range: the difference between the largest sample and the smallest sample
Does correlation mean causation? Why?
No, correlations does not mean causation. Correlation is used to determine the relationship between two variables.
What does correlation mean? What is the difference between positive and negative correlation? Give a real-life example of each.
Correlation: Correlation is an association or potential relationship between two variables
* Positive correlation: If one variable increases, the other variable also increases; similar trends
- EX) Positive correlation - ice cream sales and traffic accidents are increased during the summer and have a strong correlation
* Negative correlation: If one variable increases, the other variable decreases; opposite trends
- EX) Negative correlation - ice cream sales are increased and traffic accidents are decreased during the summer and have a strong correlation
Describe correlation coefficients & how they are used
— Correlation coefficient is between -1 and +1
— Positive number = Positive correlation
— Negative number = Negative correlation
— Closer to (+,-) 1 = strong; closer to 0 = weak
— used to see whether or not the correlation is strong or weak
What is standard deviation?
Standard deviation is how varied the values are around the mean.
Given, 2, 4, 6, 8 and the standard deviation is 2.6, how would you write the average with its standard deviation in a scientific publication? For this given data set, the average with its standard deviation would be written as:
The average is 5 and the standard deviation is 2.6, so it would be written as 5 ± 2.6
What is a t-test?
t-test is a statistical test when comparing two groups to see if they are different or not
How is the t-test different from an ANOVA test?
The t-test statistically compares only two groups to see if they are different or not; whereas the ANOVA test compares multiple groups.
What is p-value?
Produce by the t-test, the p-value is a probability value that determines whether or not the two groups being tested are significantly different or not.
How can you tell if a group is significantly different or not compared to another group?
We can use the data to calculate the p-value so that we can determine whether a certain group is significantly different than the other.
— A value that’s LESS OR EQUAL to 0.05 would be considered SIGNIFICANTLY DIFFERENT.
— A value that’s greater than 0.05 is considered NOT SIGNIFICANTLY DIFFERENT
Which type of graph is better when comparing averages?
Bar graph is better when comparing averages
Which type of graph is better when seeing how data changes over time?
A line graph is better when seeing how data changes over time.
Which type of graph do you use for finding correlation or relationships?
You would use a scatter plot to find correlations or relationships.
By looking at a correlation graph, how can you tell if it is a positive/negative or strong/weak correlation?
One can tell if a correlation graph is positive from seeing if the trend line ascends to the top right. However, a negative correlation depicts a trend line that descends to the bottom right. Furthermore, a strong correlation shows data points that are much closer to the trend line, compared to a weaker correlation, where the data points are much scattered from each other.
Interpret a p-value
p-value is less than or equal to 0.05, it is significantly different. If the p-value is greater than 0.05 it is not significantly different.
Recall all the experiments conducted for lab 02
Experiment 1: Hydrophobic vs Hydrophilic
Experiment 2: Osmosis
Experiment 3: Tonicity
Define hydrophobic/non-polar
- Hydrophobic = “water fearing”
- molecules that do not interact well with water and other polar or charged molecules; would rather interact with the opposite
Define hydrophilic/polar
- Hydrophilic = “water loving”
- molecules that interacts with polar and/or charged molecules; does NOT interact well with hydrophobic molecules
Define solute
Solutes: molecules that will dissolve in a solvent to make a solution
Define solvent
Solvent: a liquid that dissolves solutes to make a solution
Define solution and give an example
Solution: is made of solutes dissolved in solvent
EX) Salt water (solution) = NaCl (solute) +wtaer (solvent)
Define semi-permeable/selectively permeable
Semi-permeable/selectively permeable: the plasma membrane allows certain molecules or ions to pass through it while preventing others from passing
Define Brownian movement/motion
Brownian movement/motion: random motion of particles
Define passive transport
Passive transport: the movement of going down/with its concentration gradient
- high to low concentration
- DOES NOT require ATP/energy
Define active transport
Active transport: uses ATP to transport particles mostly from low concentration to high concentration or up/against its gradient
Define diffusion
Diffusion: has small, uncharged, or non-polar (hydrophobic) molecules passing through the plasma membrane down its gradient
Define osmosis
Osmosis: diffusion of water
- example of diffusion with channel proteins
Define aquaporins
Aquaporins: channel proteins allow water, being polar, to pass through the plasma membrane
Define facilitated diffusion
Facilitated diffusion: uses carrier proteins to transport molecules down its gradient
How do carrier proteins differ from channel proteins?
Carrier proteins - have an active site to bind to the molecule and have a conformational change, or shape change, to carry its molecule across the membrane
Channel proteins - may open or close to allow the molecule to pass through it
Define symport/cotransport and give an example
Symport/cotransport; has both molecules going in the same direction
EX) The sodium-glucose cotransporter: uses sodium’s concentration gradient to move the glucose against its concentration gradient
Define antiport/countertransport and give an example
Antiport/counteransport: has one molecule going in one direction and the other molecule going in the opposite direction
EX) The sodium-calcium exchanger
Define isotonic/isotonicity
Isotonic/isotonicity: when the concentration of solutes is the same intracellularly and extracellularly
- the prefix “iso,” meaning the same
Define hypertonic/hypertonicity
Hypertonic/hypertonicity: when the amount of solutes extracellularly is greater than intracellularly
- the prefix “hyper,” meaning over
Define crenate/crenation
Crenate/crenation: the shrinking of cells due to cells losing its cytosol by being attracted to the solutes outside of the cell
Define hypotonic/hypotonicity
Hypotonic/hypotonicity: when the amount of solutes extracellularly is less than the amount intracellularly
- the prefix “hypo,” meaning lower
Define hemolyse/hemolysis
Hemolyse/hemolysis: Erythrocytes breaking open from becoming bloated due to the cell taking in too much water with a hypotonic solution
Name the type of molecules that are permeable to the cell membrane & explain the reasoning
Molecules that are small, non-polar, and uncharged can easily pass through the plasma membrane since the fatty acids tails of the membrane are non-polar as well.
Name the type of molecules that are impermeable to the cell membrane & explain the reasoning
Large, charged, or polar molecules are preventable from passing through, because the middle portion of the plasma membrane is made of non-polar, hydrophobic, fatty acids
- Can only pass unless there are proteins that are embedded in the plasma membrane to allow these molecules to pass through.
Compare the extracellular vs. intracellular concentrations of Na+, K+, Cl- & Ca2+ ions
- [K+]intracellular > [K+]extracellular
- [Na+]intracellular < [Na+]extracellular
- [Ca2+]intracellular < [Ca2+]extracellular
- [Cl-]intracellular < [Cl-]extracellular
If you had 2 m of glucose, what is its osmolality in mOsm? (Show your work)
2m * 1000 = 2000 mOsm
If you had 2 m of NaCl, what is its osmolality in mOsm? (Show your work)
2m x 2 = 4 Osm
4 x 1000 = 4000 mOsm
Distinguish high vs. low osmotic pressure
- Osmotic pressure is proportional to osmotically active solute concentration
— Greater solute concentration of a solution, greater the osmotic pressure
— Lesser solute concentration of a solution, lesser the osmotic pressure
What will happen to the erythrocytes in hypertonic solution?
Erythrocytes will shrink (crenate)
What potentially happens to erythrocytes when placed in a hypotonic solution?
Erythrocytes will bloat, potentially breaking open (hemolyse/hemolysis )
What is normal saline? And how does that compare to blood’s concentration for NaCl?
Normal saline is an Intravenous (IV) solution that is 0.9% NaCl (isotonic)
- Normal saline = Concentration of NaCl in blood (0.9% NaCl)
What is D5W? And how does that compare to blood’s concentration for glucose?
D5W is an Intravenous (IV) solution that is 5% dextrose (in water)
- D5W is isotonic compared to blood’s concentration for glucose, however is hypotonic if given to a patient
Using 1 L of normal saline, calculate the osmolality. Remember NaCl has a molecular weight of 58.5 g/mol. Also, 1 L = 1,000 g. (Show your work)
(0.9g NaCl/100mL)(1000mL/1L) = 9g NaCl/ 1L
(9g NaCl/1L)(1 NaCl mols/58.5g NaCl) = 0.153846154
(0.153841615 m)(2) = 0.307692308 Osm
What is the tonicity of normal saline compared to blood?
The tonicity of normal saline is 0.9% NaCl, which is an isotonic solution, therefore is isotonic when compared to blood.
Using 1 L of 5% dextrose, calculate the osmolality. Remember glucose has a molecular weight of 180 g/mol. Also, 1 L = 1,000 g. (Show your work)
(5 g/ 100 L) * (1 mol / 180 g) * (1000 mL / 1 L) = 0.227m
0.227 m * 1 = 0.28 Osm
What is the tonicity of 5% dextrose compared to blood? And what happens when given to a patient?
D5W, or 5% dextrose, is isotonic. Cells will begin to metabolize the glucose when the patient is given this. The blood would become hypotonic because the cell would contain even more glucose. After then, water will enter the cells, causing them to hemolyze.
After doing experiment #1 of lab 02, how do you know which layer was water and which layer was xylene?
Water was at the bottom due to being much denser than xylene, which settled at the top.
Which of the substances in experiment #1 of lab 02 was hydrophobic? Which layer was it found in?
Vegetable oil was hydrophobic and found within the xylene layer. They are both nonpolar.
Which of the substances in experiment #1 of lab 02 was hydrophilic? Which layer was it found in?
KMnO4 is the hydrophilic substance in this experiment and is found within the water.
Which of the substances in experiment #1 lab 02 was both hydrophobic and hydrophilic? Which layer was it found in?
Detergent is both polar and nonpolar, making it both hydrophobic and hydrophilic. The detergent was found in between water and KMnO4 at the bottom and the xylene and oil at the top.
What caused the molasses to move up the thistle tube?
With molasses having a higher solute concentration and less water concentration, osmosis occurs, making water molecules flow from an area of high water concentration (less solute concentration) to an area that has less water concentration(higher solute concentration), causing the molasses to move up the thistle tube.
- Molasses is also considered an osmotically active solute (NOT permeable to the membrane)
In our experiment we used 20% molasses, what will happen if we used 50% molasses? Why?
The rate of water that’s entering would increase and molasses would travel further up the thistle tube, because the higher solute concentration of the molasses, the higher the osmotic pressure
What is molality (m) and milliosmolality (mOsm) of 10 g/dL NaCl
(10g/1dL)(1mol/58.5g)(10dL/1L)= 1.71mol/1L= 1.71 m
3.42 Osm *1000= 3,418.80 mOsm
What is molality (m) and milliosmolality (mOsm) of 3.5 g/dL NaCl
(3.5g/1dL) *(1 mol/58.5g) * (10 dL/1L) = 0.59829 mol/L = 0.59829 m
0.59829 m *2 = 1.19658 Osm * 1000 = 1196.58 mOsm
What is molality (m) and milliosmolality (mOsm) of 0.85 g/dL NaCl
0.15 m
290.60 mOsm
What is molality (m) and milliosmolality (mOsm) of 0.45 g/dL NaCl
(0.45g/1dL)(1mol/58.5g(10dL/1L)= 0.08mol/1L = 0.08m *2= 0.15 Osm
0.15 Osm *1000= 153.85 mOsm
What is molality (m) and millosmolality (mOsm) of 0.20 g/dL NaCl
(0.20g/1dL)(10dL/1L)(1mol/58.5g)=0.03m NaCl=0.03 m *2= 0.06838 Osm
0.06838 Osm * 1000 = 68.38 mOsm
Given the following, a semipermeable membrane that is impermeable to solutes but is permeable to water has an extracellular glucose solution of 5 g of glucose in 500 mL of water and an intracellular salt solution of 0.5 g of NaCl in 250 mL of water. Which direction will water travel? Show your work.
Use the following molecular weights: NaCl = 58.5 g/mol ; glucose = 180 g/mol
Extracellular (glucose solution):
(5g glucose/500mL)(1 glucose mols/180g glucose)(1000mL/1L) = 5000 mols/90000 L
(5000 mols/90000 L)(1) = 0.055555556 Osm
(0.055555556 Osm)(1000) = 55.6 mOsm
Intracellular (salt solution):
(0.5g NaCl/250mL H2O)(1 mol NaCl/58.5g NaCl)(1000mL/1L) = 500 mols/ 14625 L
(500 mols/ 14625 L)(2) = 0.068376068 Osm
(0.068376068 Osm)(1000) = 68.38 mOsm
With the salt solution (intracellular) having a higher concentration of solutes compared to the glucose solution (extracellular), which has less concentration of solutes, water will flow intracellularly (salt solution), since water flows from high concentration to lower concentration.
