Exam 1 Flashcards
In structure function relationships, if a nucleus is observed to be euchromatic, it is
likely that the cell is…
Actively transcribing its DNA
The process of maintaining physiological stability in the face of changing environmental conditions is referred to as…
Homeostasis
Subdisciplines of physiology include all of the following except:
All of these are
Which of the following specializations are NOT found on the lateral surfaces of
epithelial cells?
Hemidesmosomes
In regards to the tissue layers of many internal organs, such as the stomach, a layer
of epithelia that lines the lumen is referred to as the…
Mucosa
With respect to thermoregulation, most fishes are…
Conformers
The physiological process of regulation that maintains steady state conditions is
called…
Negative feedback
Which type of connective tissue (ct) comprises tendons and ligaments?
fibrous (dense) ct
The components of physiological regulation include all of the following EXCEPT:
All of these are components of physiological regulation
Which of the following statements is true?
Homeostasis is the tendency toward relative stability in the internal
environment of an organism
In physiological terms, a set point can be defined as…
the value of a parameter, such as the concentration of sugar in the blood,
that homeostatic mechanisms aim to maintain
Prior to being used as subjects, many laboratory animals are given a period of
time to get used to the conditions in the laboratory, e.g., the light/dark cycle. The
process they undergo during this time is referred to as
acclimation
Which of the following is an example of positive feedback?
ovulation in females
Which of the following represents the highest or lowest level of an environmental
variable at which an animal can survive indefinitely?
Critical value
An example of an organism or group of organisms that is (are) both a metabolic
poikilotherm and a behavioral homeotherm is…
most reptiles
Connective Tissue includes all of the following EXCEPT:
Nerves
Physiology is defined as…
The study of how living organisms function. For this, it is important to understand normal conditions.
Adaptation is defined as…
gradual change over many generations
Acclimization is defined as…
change of an individual over its lifetime of biochemical/anatomical alterations
Acclimation is defined as…
Acclimization, but induced by experimentation
What is the human blood pH range?
7.35 - 7.45
The normal blood concentration range for sodium is…
135 - 145
The normal blood concentration range for calcium is…
2.1-2.8
The normal blood concentration range for potassium is…
3.5 - 5
The normal blood concentration range for chloride is…
95-105
The normal blood concentration range for pCO2 is…
35 - 45
The normal blood concentration range for HCO3- is…
22 - 26 mEq/liter
August Krough Principle states that…
For every well-defined physiological problem, there is an animal optimally
suited to yield an answer/understanding physiological phenomena is enhanced by studying model
organisms that have adapted to deal with particular physiological challenges
An enzyme functions to increase the rate of reaction by…
reducing activation energy
Protein function and activity can be modified by…
All of the above (allosteric regulators, changes in electric fields, phosphorylation and changes in pH)
A competitive inhibitor functions by…
Binding to the activation site
Which of the following bases is unique to DNA?
thymine
A molecule that has both polar and nonpolar groups is said to be:
amphipathic
Which of the following statements regarding lipid membranes is true?
Membrane lipids move laterally within their own layer
Which of the following statements regarding the fatty acid tails of phospholipids
is FALSE?
Phospholipids with unsaturated tails make the bilayer more fluid because
the tails contain fewer hydrogens and thus form fewer hydrogen
bonds with each other.
Which level of protein structure refers to the folding of the amino acid chain to
produce globular or rod-like molecules?
Tertiary structure
In terms of energetics, a substance is transported down its concentration
gradient by what kind of transport?
Passive
Which of the following bases is unique to RNA?
Uracil
Glycogen has what kind of linkages in the 1-4 position?
Alpha
What is the process called when DNA unwinds to create a copy in mRNA?
Transcription
A compound that binds to the active site of an enzyme to reduce the enzymes
activity is called a…
Competitive inhibitor
A process in which food molecules are oxidized incompletely to lactic acid is
called…
Anerobic respiration
What drives respiration?
Lower pH
Why is it not always good to just treat patients by giving them more oxygen?
You are not getting rid of the CO2. You really need to lower the pH.
What are the three classes of fats?
Lipids, phospholipids (membranes), waxes
Unsaturated fats generally…
Have a lower melting point and increased membrane fluidity
What kind of bonds would an arctic penguin want to have in its membranes?
More unsaturated bonds, because it does not need to worry about heat melting the membranes
How do lipids that are made inside the cell get out?
Flipase flips it to outside
What is the backbone of fatty acids?
Glycerol
What is one way fatty acid chain length can increase fluidity?
By making some chains short and some long to decrease interaction between chains
Why do fats make good energy stores?
Little water needed, stored in adipose, high [H and C], low [o]
Formula for the brakdown of glucose?
C6 O2 H6 + 6 O2 –> 6 CO2 + H2O (metabolic water) + ATP + Heat
What are the two classes of carbs?
Monosacharides and disacharides
Animals store carbs as ____, plants store them as _____
Glycogen, starch
How much of the dry mass of a cell is protein?
1/2
What is primary protein structure?
Line of peptide bonds
What is secondary structure?
Alpha helix vs. beta sheets dependent on H+ bonding
What is tertiary structure?
Folds onto itself, covalent disulfide bondage
What is quaternary structure?
Subunits held together (ex. hemaglobins)
What are heat shock proteins? (Molecular chaperones)
Proteins that protect against heat denaturation. Animals survived when HSP was genetically knocked down, and this led to the discovery of HSP redundancy
What is significant about a GC rich region?
More H+ bonds, so breaks down less easily
What are the two types of energy?
Thermal and mechanical
What is the Gibbs free energy equation?
DeltG = DeltH - T DeltS
Why does ATP have a negative DeltG?
4 oxygens right next to eachother
Competitive inhibitor?
Competes for the same site
Non-competitive inhibitor?
Changes the enzyme conformation
As you add competitive inhibitor, what happens to the Lineweaver plot?
The slop of the line changes
As you add non-competitive inhibitor, what happens to the Lineweaver plot?
Changes the y-int
What is GABA?
An inhibitory transmitter that leads to decreased excitation
Anerobes undergo ____ to form ATP, while aerobes undergo ______.
Glycolosis only, glycolosis and ETC
How many net ATP come from glycolosis?
2 (4 total)
How many net ATP come from the TCA cycle and ETC?
36
The liver uses _______, while the muscle uses _____ to deal with lactate
Gluconeogenesis, glycolysis
Which muscle requires more mitochondria; fast twitch or slow twitch?
Slow twitch
The major types of lipids typically found in cell membranes does NOT include…
Phosphodiesterase
Which of the following does NOT directly affect the rate of diffusion of a
substance across a membrane?
Cellular volume
Osmotic pressure is…
both a & b are correct (equal to the hydrostatic pressure required to oppose the movement of
water into the solution whose osmotic pressure is being evaluated and equal to the hydrostatic pressure required to drive water into the solution
whose osmotic pressure is being evaluated
The observation that separate carrier proteins are required for the import of
glucose and amino acids is an illustration of the carriers’ property of
Specificity
Functions of membrane integral proteins does NOT include
As ion reservoirs
An example of chemiosmotic energy transduction is…
the redox reaction of the mitochondria
The binding constant of an enzymatic reaction is defined as…
the concentration of solute at ½ Vmax
The types of lipids in cell membranes may include any of the following
EXCEPT…
micelles
Cholesterol affects membranes by…
decreasing fluidity and increasing rigidity
Singer and Nicolson…
proposed the fluid mosaic model of cell membrane
Which of the following is NOT a function of cell membrane proteins?
All of these are functions of membrane proteins (ion channels, membrane pumps, receptors, enzymatic)
Which of the following is how most animals maintain cell volume?
Animals actively pump out solutes that leak into cell
Which of the following has a linear relationship between substrate
concentration and rate of flux, even at high concentrations?
Passive diffusion through the membrane
Movement of a solute across an epithelial layer that passes BETWEEN the
epithelial cells is called…
The paracellular path
For animals, increasing cholesteroldoes what to fluidity?
Decreases (breaks up chains)
Hydrostatic pressure is…
The pressure to pull water out
Which transport mechanisms are not active?
Symport, antiport, uniport
___ Na+ goes in and ___ K+ goes out of the cell
3, 2
What are 5 ways that pumps are controlled?
- Pumps = enzymes = amino acids with charges, so this can prevent some molecules from entering.
- Size of the ion/channel can also be limiting
- Charge of the ion
- If the ion is charged in such a way to attract water, it forms a hydration sphere that makes it larger (cannot fit through)
- The charge nature at the mouth of the channel can attract/repel ions
How are larger molecules transported?
Ca2+ causes clathrin coated pits to for, forms vesicle
What are gap junctions?
Channels from one cell to another. Small molecues and electrical signals can travel very fast through them. Large molecules can block them. Responsiblle for rapid movements in animals
Is the movement of sodium into the cell active or passive?
Passive, but it is due to the secondary action of the active Na/K pump
Interior [Na+]?
10mM
Interior [K+]?
140mM
Interior [Ca2+]?
less than 10^-3
Interior [Cl-]?
3-4
How does depolarization of a neuron membrane cause an ion channel to open?
Alteration of the electric field across the membrane causes a region of the
channel protein to change conformation
If the equilibrium potential for chloride ions is equal to a cell’s resting
membrane potential, and chloride-specific channels in the plasma membrane
are suddenly opened, what would most likely happen?
The membrane potential would not change
In the ‘relative refractory’ period following an action potential, further APs can
be generated but they require greater depolarization of the membrane than the
first AP. Why?
A proportion of the voltage-gated sodium channels are inactivated
Receptor proteins of the plasma membrane
all of the above are true ( have binding sites that recognize specific molecules, are integral membrane proteins, and have a portion in the cytoplasm that activates post receptor pathways)
How does depolarized of a neuron membrane cause an ion channel to open?
Alteration of the electric field across the membrane causes a region of the
channel protein to change conformation
Which two regions of a neuron’s plasma membrane are likeliest to have the most
DIFFERENT specific resistivities (Rm) during the time when action potentials
are being generated?
Soma and axon hillock
Which of the following accurately describes a capacitative current across a cell
membrane?
If there is an increase of charge density on one side of the membrane, the
density of like charges on the other side decreases
A neuron at rest has a Vrest of -65mV. If a sodium channel were to open, what
would be the EMF driving sodium ions through the channel if ENa= +50mV, EK=
-70mV, and ECa = +150mV?
115mV
When voltage-gated ion channels open, a slight ‘gating current’ can be
measured. What is the nature of this current?
When the membrane depolarizes sufficiently to open the channel, a
segment of the channel protein moves toward one of the membrane
surfaces
Neurons generally have only a single spot at which action potentials can be
generated. What characteristic explains this phenomenon?
Other regions have fewer voltage-gated ion channels per unit of membrane
surface area
Which of the following is most likely to be true of a hyperpolarized neuron
membrane?
Lower than resting [K+]in and higher than resting [Na+]out
Tetrodotoxin, an extremely potent poison produced by the puffer fish, binds
tightly to voltage-gated sodium channels and blocks the flow of sodium ions but
does not affect either potassium or chloride ion channels. Tetrodotoxin directly
blocks which phase of an action potential?
Depolarization
Which type of supportive cell is located in the central nervous system
oligodendrocytes
Ohms law is defined as…
ΔVm = ΔI x R
What is the ability of the membrane to store charge by electrical means
called?
membrane capacitance
Membrane ion conductance depends on what?
Both A and B are correct (density of ion channels, surface area)
An electrical field across a typical cell membrane is approximately
60 million Volts/M
Which of the following is NOT correct?
Cell membranes are relatively permeable to Na+
The Nernst Equation at 18C can be reduced to…
Ex = 58/Z x log ([x+]o/[x+]I)
An ionic current can only flow across a membrane IF…
both A and B are correct (there is a conductance across the membrane, the is an emf for the ion)
In the ‘relatively refractory’ period following an action potential, further APs
can be generated but they require greater depolarization of the membrane
than the first AP. Why?
A proportion of the voltage-gated sodium channels are inactivated
Squid are frequently studied by neurobiologists because…
Their large axons allow thin electrode wires to be threaded through them
longitudinally
