MCAT Flashcards
The _____ of a wave is directly proportional to its _____, but inversely proportional to its _____
The energy of a wave is directly proportional to its frequency, but inversely proportional to its wavelength
Define: Doppler Effect and its Result
An increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move toward (or away from) each other.
The effect causes the sudden change in pitch noticeable in a passing siren.
Shifts frequency, not intensity, so cannot dampen sounds
________does not change when the wave travels from one medium to another!
Frequency does not change when the wave travels from one medium to another!
Why doesn’t _____ change when going through different mediums?
What happens to frequency?
What happens to wavelength?
What happens to speed of wave?
When waves travel from one medium to another the frequency never changes.
As waves travel into the denser medium, they slow down and wavelength decreases. Part of the wave travels faster for longer causing the wave to turn.
The wave is slower but the wavelength is shorter meaning frequency remains the same.
What is Interference? (Waves)
What are the different types?
What do the different types look like?
The combination of 2 or more waves. Can be constructive or destructive
What is Constructive Interference?
Interference: The combination of 2 or more waves.
When the waves are in-phase (crest meets crest, trough meet trough), this is Constructive Interference.
What is destructive interference?
When the waves are out-of-phase (crest meets trough, trough meets crest), this is destructive interference and the amplitude (maximum displacement of a wave from its equilibrium) of the resultant wave is equal to the difference between the 2 individual amplitudes
Decreases amplitude, therefore energy, and thus loudness
What is the relationship between amplification, energy, and frequency?
The amplitude, or vertical height, of a wave is defined as half the peak-to-trough height; as the amplitude of a wave with a given frequency increases, so does its energy
Define Wavelength
The distance between two corresponding points in a wave—between the midpoints of two peaks, for example, or two troughs—is the wavelength (λ)
Define frequency, what are its units?
The frequency (ν) of a wave is the number of oscillations that pass a particular point in a given period of time. The usual units are oscillations per second (1/s = s−1), which in the SI system is called the hertz (Hz)
Define: Amplification
A result of constructive interference
What changes in a molecule would you expect in a Nucleophilic Addition?
would expect to see a pi bond in the molecule break in order to form two new sigma bonds.
What is Hydrolysis? What are 3 common types?
Hydrolysis - hydrolysis is a chemical reaction in which water is used to break down the bonds of a particular substance.
Opposite of condensation (combination of 2 molecules that results in the release of H2O).
Salts: Hydrolysis occurs when salt from a weak base or acid dissolves in liquid. When this occurs, water spontaneously ionizes into hydroxide anions and hydronium cations. This is the most common type of hydrolysis.
Acid: Water can act as an acid or a base, according to the Bronsted-Lowry acid theory. In this case, the water molecule would give away a proton. Perhaps the oldest commercially-practiced example of this type of hydrolysis is saponification, the formation of soap.
Base: This reaction is very similar to the hydrolysis for base dissociation. Again, on a practical note, a base that often dissociates in water is ammonia.
Define: Saponification
Saponification - describes basic hydrolysis of ester bonds. Typlcally a triglyceride
What would you expect to see in an oxidation reaction?
Oxidation - more oxygen appears in molecule
Oxidation: gain oxygen, lose hydrogen, lose e-
What is a dehydration reaction?
Dehydration - the removal of water from a molecule
What is a lipase? What is its role?
Lipase - an enzyme that breaks down fats (which contain 3 esters)
A lipase is any enzyme that catalyzes the hydrolysis of fats. Lipases are a subclass of the esterases. Lipases perform essential roles in digestion, transport and processing of dietary lipids in most, if not all, living organisms.
What is the most common biomolecule is an amide present in?
Amides - Functional groups present in proteins
What is a hemiacetal?
What common biomolecule is it found in?
Hemiacetals - functional groups present in sugars
What common biomolecules are ethers found in?
Ethers - not largely important for biological molecules
Define: Gauge Pressure
The pressure relative to atmospheric pressure
Positive for pressures above atmospheric pressure
Negative for pressures below atmospheric pressure
Atmospheric pressure adds to pressure of any fluid not enclosed in a rigid containers. Happens because of Pascal’s Principle
Define: Absolute Pressure
Sum of gauge pressure and atmospheric pressure
Pabs = Pg (gauge) + Patm (atmosphere)
Can never be negative
Because fluids push rather than pull, the lowest absolute pressure can be is zero.
Define: Ambient Pressure
Pressure of the surrounding medium (gas or liquid) of an object
Define: Systolic Pressure
Maximum Blood Pressure
Define: Diastolic Blood Pressure
Minimum Blood Pressure (like when you die
(diastolic) your blood pressure will be very low)
Paramagnetic
electron orbital half-filled
attracted to magnet
Diamagnetic
All electrons are paired in valence shell
Not attracted to magnet
Energy of excitation is _______ to energy of emitted photon
Energy of excitation is directly proportional to energy of emitted photon
Valence Structure refers to _____ in the periodic table
Valence structure refers to the family or column in the periodic table (because family/column have identical valence structures)
______ always lose their valence “s” electrons before any “d” electrons
Transition Metals always lose their valence “s” electrons before any “d” electrons
Triple bonds have ___ pi bonds and ___ sigma bonds
Triple bonds have 2 pi bonds and 1 sigma bond
Double bonds have ___ pi bonds and ___ sigma bonds
Double bonds have 1 pi bond and 1 sigma bond
Single bonds have ___ pi bonds and ___ sigma bonds
Single bonds have 0 pi bonds and 1 sigma bond
The amount of Acetyl-CoA produced via B-oxidation is ___. The number of rounds in B-oxidation is determined via ___
The amount of Acetyl-CoA produced via B-oxidation is C/2. The number of rounds in B-oxidation is determined via (C/2)-1
For each Acetyl-CoA that enters the TCA cycke generates: ___ NADH and ___ FADH2
For each Acetyl-CoA that enters the TCA cycke generates: 3 NADH and 1 FADH2
Disulfide bonds are most easily broken via _______ to their thiol state
Disulfide bonds are most easily broken via reduction to their thiol state
______ is responsible for forming disulfide bonds
oxidation is responsible for forming disulfide bonds
When Kreb’s Cycle is halted, conditions are (aerobic/anaerobic)
Conditions are aerobic still. The ETC is still functional.
Cell would end up consuming more glucose to compensate for loss of ATP production supplied by Kreb’s Cycle.
A molecule is _________ if it does not have any carbons in which all 4 substituents are different (no chiral centers)
A molecule is Optically Inactive if it does not have any carbons in which all 4 substituents are different (no chiral centers)
Define: Osmotic pressure
The solution with _____ [solute] has ______ osmotic pressure
The pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution via osmosis
The solution with greater [solute] has greater osmotic pressure
Define: Hypertonic Solution
When osmotic pressure of solution outside the cell is greater than osmotic pressure inside the cell
Water exits to equalize osmotic pressure
Concentration outside is greater than concentration inside