Physiology Test 2 Flashcards
What is the most abundant extracellular cation?
sodium(Na+)
What is the most abundant extracellular anion?
Chloride(Cl-)
What is the most abundant intracellular cation?
Potassium(K+)
What is the most abundant intracellular anion?
inorganic phosphate
What molecule is a co-factor for almost all chemical reactions?
magnesium
What is a byproduct of the kreb cycle and what type of metabolism is it a result of?
CO2, aerobic metabolism and its comes from a carboxyl group
What is the function of ribosomes?
protein synthesis
What are the average extracellular and intracellular concentrations of sodium(Na+)?
140 mEq/L and 14 mEq/L
What are the average extracellular and intracellular concentrations of potassium(K+)?
4 mEq/L and 140 mEq/L
What are the average extracellular and intracellular concentrations of calcium(Ca2+)?
2.4 mEq/L and 0.0001 mEq/L
What are the average extracellular and intracellular concentrations of magnesium(Mg2+)?
1.2 mEq/L and 58 mEq/L
What are the average extracellular and intracellular concentrations of chloride(Cl-)?
103 mEq/L and 4 mEq/L
What are the average extracellular and intracellular concentrations of inorganic phosphate(HPO4)?
4 mEq/L and 75 mEq/L
What are the average extracellular and intracellular concentrations of glucose?
90 mg/dL and 0-20 mg/dL
What are the average extracellular and intracellular concentrations of pO2?
35 - 40 mmHg and ~20 mmHg
What are the average extracellular and intracellular concentrations of pCO2?
40 - 45 mmHg and ~45 - 50 mmHg
What are the average extracellular and intracellular concentrations of Amino Acids?
30 mg/dL and 200 mg/dL
What are two major categories by which molecules move across the cell membrane?
- Simple diffusion
2. Active transport
What is another name for diffusion?
passive transport
How does simple diffusion occur?
molecule moves with the gradient, from higher to lower gradient(down the hill), does not utilize ATP
How does active transport occur?
molecule moves against the gradient from lower to higher gradient(up the hill)
What drives active transport?
energy is taken from ATP to drive the active process
What substances diffuse directly through the cell membrane by simple diffusion(4)?
oxygen
carbon dioxide
nitrogen
alcohol
Molecules that diffuse directly across the cell membrane, are what soluble?
lipid/fat soluble substances
What types of molecules needs help transversing the cell membrane? And what types of channels do they move through(still referring to simple diffusion)?
- those that are water soluble(cell membrane is made up of lipids) and those that are electrically charged(anions and cations—>the cell membrane is polar)
- protein channels
What is the main characteristic of a protein channel?
its selectively permeable
What are the three factors that determine the selective permeability of each protein channel?
- size
- shape
- electrical charge within the channel
What are two types of protein leak channels?
- sodium leak channel
2. potassium leak channel
What is the characteristic of a leak channel?
Leak channels are always open allowing substances to move across the cell membrane from a higher gradient to a lower gradient
What is the characteristic of a sodium leak channel?
sodium diffuses with the gradient from outside of the cell to the inside of the cell, sodium has a {} outside of the cell
What is the characteristic of a potassium leak channel?
potassium diffuses with the gradient from the inside of the cell to the outside of the cell.
Is the influx and output of Na+ and K+ evenly matched in and out of the cell, or does one come in or go out more? and why?
More potassium diffuses out of the cell than sodium leaks into the cell. Sodium molecules are surrounded by water which makes them larger which makes them not diffuse as rapidly as potassium which are smaller
What types of gradient determines the movement of solutes/molecules in protein leak channels?
electrical gradient
concentration gradient
or both
What are the characteristics of gated protein channels.
- channels can be alternately opened and closed
2. channels allow diffusion only when gate is open
What are two types of Gated Protein Channels?
- Ligand(chemical) Gated Channels
2. Voltage Gated Channels
What is the neurotransmitter(Ligand) that opens the Ligand(chemical) Gated Channel and allows Na+ to enter the cell?
acetylcholine binds to the receptor site
Once the Ligand is removed from the receptor site, what happens to the gate?
It closes
What is the name of the enzyme that removes acetylcholine from the receptor site of the Ligand Gated Channel?
acetylcholinesterase
What is the characteristic of a Voltage Gated Channel.
a change in the voltage across the cell membrane opens the voltage channel. for example if the voltage changes by 30 mV it opens the gate.
What’s the difference between a fast voltage channel and a slow voltage channel?
fast voltage gated Na channel only takes about 30 mV, where as a slow voltage channel such as potassium voltage channel takes about a 90 mV change to open the gate. so Fast Voltage Na Channel 30 mV versus a Slow Voltage Potassium Channel 90 mV
As the sodium gates are closing…the potassium gates are just beginning to open
What amount of voltage change is required to open and close the Voltage Gated Channels?
~30 mV change to open the gate
~90 - 100 mV change to close the gate
What type of transport describes ALL types of diffusion?
Passive
What types of Sodium/Potassium channels are there(3/2)?
Sodium/Potassium Leak Channels
Ligand Gated Sodium channels
Voltage Gated Sodium/Potassium Channels
What type of diffusion is Facilitated(Carrier Mediated) Diffusion?
All types of diffusion is PASSIVE!
How is a molecule transported across the cell membrane by facilitated diffusion?
The molecule that needs to cross the cell membrane binds to a receptor site, once the saturation point has been reached the channel opens allowing the molecule to cross to the other side
What is a Major example of molecule/substance that crosses the cell membrane by facilitated diffusion?
Glucose
Glucose transporters are an example of what type of transport?
facilitated diffusion
How is insulin involved in facilitated cell transport?
insulin regulated the number and activity of glucose transporters(GLUT)
What cells are not dependent upon insulin to regulate glucose transporters to enter the cells(5)?
- neurons
- hepatocytes(insulin does increase glucose transport into hepatocytes
- Proximal tubules of the kidneys
- small intestines
- exercising skeletal muscle fibers require less insulin for glucose transport than resting skeletal muscle fibers
What is a major characteristic of facilitated diffusion?
a saturation point! If there is more glucose outside the cell wanting in than there are protein channels that can take it in what happens? They stay outside the cell and the person is hyperglycemic.
How does the surface area of the cell membrane affect rate of diffusion(all types of diffusion)?
The larger the surface area membrane the faster the rate of diffusion
How does the permeability of the cell membrane to a specific solute affect the rate of diffusion(all types of diffusion)?
The more permeable the membrane is to a specific solute the faster the rate of diffusion
How does the thickness of the cell membrane affect the rate of diffusion(all types of diffusion)?
The thicker the membrane the slower the diffusion, the thinner the membrane the faster the diffusion. The thicker the membrane the more resistance there is to diffusion!
How does lipid solubility affect the rate of diffusion across the cell membrane(all types of diffusion)?
Solutes that are highly lipid soluble diffuse faster than those that are less lipid soluble(more water soluble)
How does the number of protein channels for a specific solute affect diffusion across the cell membrane(all types of diffusion)?
as the number of channels increase, the number of solutes that can diffuse increases—>increased rates of diffusion!
How does temperature affect the rate of diffusion across the cell membrane(of all types of diffusion)?
As temperature increases…rate of diffusion increases
How does molecular weight of substances affect the rate of diffusion across the cell membrane(all types of diffusion)?
lower molecular weight substances diffuse faster than higher molecular weight substances
How does saturation point of protein transporters affect diffusion(for facilitated diffusion)?
The saturation point is the limit of diffusion…if all the channels are being used…any more substances can’t diffuse across cell membrane at that time…the saturation point has been reached
What are three types of gradients that affect diffusion across the cell membrane?
- concentration gradient
- electrical gradient
- pressure gradient
for a given membrane there maybe more than one of these occurring at the same time**
The equilibrium point is the net affect of how the gradients are all affecting at one time(i.e. more than one gradient may be at work at any one time—>so the equilibrium is determined by the net affect of all the gradients at any one time)
Transport by diffusion that is based on a concentration happens how? and what determines equilibrium?
molecules move inside cell via a protein channel from area of higher concentration to lower concentration. Equilibration happens when the concentration is equal on both sides of the cell membrane.
Transport by diffusion that is based on an electrical gradient happens how? and what determines equilibrium?
molecules move from one side of the cell to the other via protein channels. They are propelled through the protein channel attracted by similarly charged ions on the opposite side. The equilibrium point is not based on number of molecules on either side, rather it is an electrical equilibrium. When there is an equal charge on both sides.
Transport by diffusion that is based on a pressure gradient happens how? and what determines the equilibrium?
molecules move from one side of the cell membrane to the other from area from higher pressure to lower pressure. One the pressures become equal on both sides…the equilibrium point has been reached.
What is osmosis?
The movement of WATER across a SEMIPERMEABLE membrane from an area of lesser concentration of solutes to an area of higher concentration of solutes(from area of more water to an area of less water)
Osmosis is a faster rate of movement than that of just simple diffusion of water across a semipermeable membrane.
What is a mole?
Avogadro’s number of particles(atoms, ions, molecules)
What does 1 mole =?
Avogadro’s number 6.02 x 10^23
What is a millimole?
1 mole = 1000 millimoles(6.02x10^23/1000)
What is an osmole(osm)?
refers to the number of particles in solution
1 osmole = 1 mole(Avogadro’s number of particles) in 1 liter or 1 kg of water
What is a milliosmole(mOsm)?
1/1000 osmole(6.02x10^23/1000)
What does the atomic number refer to on the periodic table?
number of the protons/electrons in the nucleus/orbitals
What does the atomic weight refer to on the periodic table?
weight of protons and neutrons in the nucleus
What does the group number tell you of the periodic table?
It tell you how many electrons there are in the outer most orbital
for example Na atomic number is 11 so it has 11 protons/electrons. Its group number is 1 so you know it only has 1 electron in the outer most orbital.
What does the periods tell you about the molecules on the periodic table?
It tells you how many orbitals there are. For example Na has 3 orbitals because its in the 3 period
If Na+ atomic weight is 23 what does that say?
Thats the weight of the protons and the neutrons in the nucleus
Potassiums atomic number is 19, it is in group 1 period 4 and its atomic weight is 39. What does all this mean?
19 protons and electrons
1 electron in the outermost orbit
4 total orbits
the total weight of protons and neutrons is 39
Chloride’s atomic number is 17, it is in group 3 period 7 and its atomic weight is 34.45. What does all this mean?
17 protons and electrons
3 electrons in the outermost orbit
7 total orbits
the total weight of protons and neutrons is 34.45
What is an ionic bond?
Its a very weak bond caused when two element bind together to have 8 electrons in their outermost orbit. i.e. sodium chloride(1+7=8) or potassium chloride(1+7=8)
When an atom looses an atom and is no longer neutral what do we call it?
an Ion
When chlorine adds an extra atom what happens to its name? When they go from an atom to an ion.
chlorine becomes chloride
bromine becomes bromide
for example
Ionic bonds are very weak…true or false?
true
Which is the atom; chlorine or chloride?
Chlorine; chloride is the ion
What happens when a NaCl molecule is in water?
The negative poles of water attract the positive Na, the positive poles of water attract negative Cl, and the ionic bond of NaCl is broken—>ions are formed(cation: Na+, anion Cl-)
If one mole of NaCl is added to water, what is the resulting mole/moles?(Na+ atomic weight is 23/Cl- atomic weight is 35.5) What is the molecular weight of NaCl? What type of chemical bond is NaCl?
- NaCl dissociates in water into 1 mole of Na+ and 1 mole of Cl-
- 2 X Avogadro’s number of ions
- 1 mole NaCl contributes 2 osm(2 X Avogadro’s number of particles) to 1 liter or 1 kg of water
- molecular weight of NaCl is 58.5
- 1 mole NaCl = 58.5 mg
- ionic boind