Biology Test #2
Ph
1. The power of hydrogen in a solution (the amount of)
2. Acids are an increase of the number of hydrogen ions (H+) in a solution (there are
more hydrogen ions and hydronium ions than hydroxide ions).
3. Bases are an increase of the number of hydroxide ions (there are more hydroxide ions
than hydrogen ions and hydronium ions).
4. Goes from 1-14 (1 most acidic and 14 most basic)
5. Each step on a Ph scale is 10 times an increase, or decrease of H+. If you go two steps
above it's 100 times less acidic. Three steps above is 1,000 less acidic and so on. You
add a zero to the end of each.
6. Dissociation: Means that water in its normal molecular state, H2O, can separate into
two pieces.
a. H2O breaks into two separate parts ‘OH−’, a hydroxide ion, and an ‘H+’, a
hydrogen ion. The proton (H+) binds to another water molecule, forming a
hydronium ion (H3O+).
b. Hydroxide ions are proton acceptors (since it has a negative charge it will
accept positive charged protons), electron donors and if you increase the
concentration of Hydroxide ions in a solution it leads to an increase of Ph in
that solution, you make it more of a base.
c. Hydronium ions, since they are positively charged, act as a proton donors. And
it extracts electrons, making it an electron acceptor. And when you increase the
amount of hydrogen ions in a solution it leads to a decrease in Ph, you are
making it more acidic.
7. Buffer: Solutions that are there to moderate acids and bases
Diffusion
1. The net movement of a substance, traveling down its concentration gradient. It moves
from high concentration to a low concentration.
2. The solvent (ex:ethanol, things it's being dissolved in) concentration changes when the
solute concentration (ex:sugar) changes. For something to diffuse, it has to be
dissolved.
3. Concentration: Amount/volume
a. Concentration gradient: A gradual change in concentration of solutes in a
solution between two regions.
, b. Net movement: Overall movement. The molecules, though, are constantly
moving, but the overall movement is 0 when an equilibrium is reached.
4. Diffusion does not require added energy, it is a passive process. This is because
molecules have kinetic energy and are always moving. When we talk about diffusion
of molecules in cells, for example the diffusion of oxygen molecules into a cell, it is
classified as passive transport. High concentration has high potential energy and low
concentration as low potential energy.
5. Blood (Red+white blood cells) move across our bodies through diffusion. Our cell
membranes have carrier proteins that act as tunnels, which allows sugar molecules or
other substances that need to get to our cells.
Osmosis
The movement of water through a semipermeable membrane (only some things can go
through), like a cell membrane.
1. Water molecules are so small that they can travel through the cell membrane
unassisted, or they can travel in larger quantities through protein channels, like
aquaporin.
2. The movement of water molecules passing through a cell membrane is a passive
transport, meaning it does not require energy.
3. Water molecules travel from an area of high concentration of water molecules, to a low
concentration of water molecules.
a. When we say low water concentration, it also means there is a greater
solute concentration.
i. Solute are substances, like salt or sugar, that can be dissolved
within a solvent, like water.
b. Water has the tendency to move to areas where there is a higher solute
concentration, which would mean less water concentration.
4. So let's say there is a u-tube. And in the middle of this u-tube there is a semi-permeable
membrane, much like a cell membrane, where water can easily pass through it, but salt can’t.
The water on the A side and the B side are equal (and although the water molecules are always
moving, it has a net movement of zero). Now, if you dump a huge amount of salt into side B,
the salt will now start moving to side b, since it has a higher solute concentration, or in other
words, a lower concentration of water. Once equilibrium is reached, the net movement will be
zero.
c. We call side ‘b’ hypertonic, meaning it has a higher solute
concentration (or lower water concentration). But we can’t just say
something is hypertonic without comparing it to something else.
i. In osmosis, water moves to the hypertonic solution.
Ph
1. The power of hydrogen in a solution (the amount of)
2. Acids are an increase of the number of hydrogen ions (H+) in a solution (there are
more hydrogen ions and hydronium ions than hydroxide ions).
3. Bases are an increase of the number of hydroxide ions (there are more hydroxide ions
than hydrogen ions and hydronium ions).
4. Goes from 1-14 (1 most acidic and 14 most basic)
5. Each step on a Ph scale is 10 times an increase, or decrease of H+. If you go two steps
above it's 100 times less acidic. Three steps above is 1,000 less acidic and so on. You
add a zero to the end of each.
6. Dissociation: Means that water in its normal molecular state, H2O, can separate into
two pieces.
a. H2O breaks into two separate parts ‘OH−’, a hydroxide ion, and an ‘H+’, a
hydrogen ion. The proton (H+) binds to another water molecule, forming a
hydronium ion (H3O+).
b. Hydroxide ions are proton acceptors (since it has a negative charge it will
accept positive charged protons), electron donors and if you increase the
concentration of Hydroxide ions in a solution it leads to an increase of Ph in
that solution, you make it more of a base.
c. Hydronium ions, since they are positively charged, act as a proton donors. And
it extracts electrons, making it an electron acceptor. And when you increase the
amount of hydrogen ions in a solution it leads to a decrease in Ph, you are
making it more acidic.
7. Buffer: Solutions that are there to moderate acids and bases
Diffusion
1. The net movement of a substance, traveling down its concentration gradient. It moves
from high concentration to a low concentration.
2. The solvent (ex:ethanol, things it's being dissolved in) concentration changes when the
solute concentration (ex:sugar) changes. For something to diffuse, it has to be
dissolved.
3. Concentration: Amount/volume
a. Concentration gradient: A gradual change in concentration of solutes in a
solution between two regions.
, b. Net movement: Overall movement. The molecules, though, are constantly
moving, but the overall movement is 0 when an equilibrium is reached.
4. Diffusion does not require added energy, it is a passive process. This is because
molecules have kinetic energy and are always moving. When we talk about diffusion
of molecules in cells, for example the diffusion of oxygen molecules into a cell, it is
classified as passive transport. High concentration has high potential energy and low
concentration as low potential energy.
5. Blood (Red+white blood cells) move across our bodies through diffusion. Our cell
membranes have carrier proteins that act as tunnels, which allows sugar molecules or
other substances that need to get to our cells.
Osmosis
The movement of water through a semipermeable membrane (only some things can go
through), like a cell membrane.
1. Water molecules are so small that they can travel through the cell membrane
unassisted, or they can travel in larger quantities through protein channels, like
aquaporin.
2. The movement of water molecules passing through a cell membrane is a passive
transport, meaning it does not require energy.
3. Water molecules travel from an area of high concentration of water molecules, to a low
concentration of water molecules.
a. When we say low water concentration, it also means there is a greater
solute concentration.
i. Solute are substances, like salt or sugar, that can be dissolved
within a solvent, like water.
b. Water has the tendency to move to areas where there is a higher solute
concentration, which would mean less water concentration.
4. So let's say there is a u-tube. And in the middle of this u-tube there is a semi-permeable
membrane, much like a cell membrane, where water can easily pass through it, but salt can’t.
The water on the A side and the B side are equal (and although the water molecules are always
moving, it has a net movement of zero). Now, if you dump a huge amount of salt into side B,
the salt will now start moving to side b, since it has a higher solute concentration, or in other
words, a lower concentration of water. Once equilibrium is reached, the net movement will be
zero.
c. We call side ‘b’ hypertonic, meaning it has a higher solute
concentration (or lower water concentration). But we can’t just say
something is hypertonic without comparing it to something else.
i. In osmosis, water moves to the hypertonic solution.
