When a light wave and a sound wave pass from air to glass, what changes occur in their speed?
Light slows down and sound speeds up.
Light slows down: nglass>nair, which is a measure of the ratio of the velocity in air to the velocity in the medium.
Sound speeds up: Speed of sound is much greater in solids than in air, because solids have stiff rigid bonds
that give rise to a speed more than 10x greater than air.
What is Avogadro's number?
What causes friction?
Attractive molecular forces between surfaces in contact
What law always applies after a collision? What can you assume?
Newton's 3rd Law; you can assume that the forces of collision are equal and opposite.
What does the frequency shift of the Doppler effect for radio waves depend on?
The relative velocities (motion) of the source and the detector
Why are percentages of the change in f & wavelength much greater when sound waves are used instead of radio waves?
df/f=-v/c for a given relative velocity v between source & detector.
So, change in frequency is inversely proportional to speed of wave in the medium in which it propagates, c.
Since the velocity of sound is much smaller than velocity of electromagnetic radiation, for the same relative velocity, the freq and wavelength shifts are much greater for sound than for radio waves. esp since c is the same for both.
If a receiver is in a jet flying alongside another jet emitting waves and they're traveling at same speed, what is the change in frequency detected at receiver?
0 Hz (bc there's no relative motion bt jets, so no freq shift)
Mechanical waves in a medium such as water function to transport:
Mechanical waves, such as sound and water waves, are a local oscillation of material. Only the energy propagates, but the oscillating material does not move far from its initial equilibrium position.
What does the ectoderm develop into? (5)
The outer coverings of body: Epidermis, nails, tooth enamel, cells of nervous system & sense organs.
What does mesoderm develop into? (3)
The mesoderm is the stuff that lies between the inner and outer covering of the body: the muscle, the bone, and the rest of the internal organs that the endoderm doesn't cover.
What does the endoderm develop into? (5)
The digestive tract; respiratory tract; parts of the liver, pancreas, and bladder.
Which type of RNA has short double-stranded segments?
tRNA - when the nucleotide chain loops back upon itself.
What are the basic types of proteins in the body? (5) Based on function!
- 1. Hormones
- 2. Enzymes
- 3. Structural proteins
- 4. Transport proteins
- 5. Anti-bodies
What is the definition of a species?
Organisms can mate with each other under natural conditions to produce viable, fertile offspring
When do we see haploid somatic cells?
NEVER - somatic cells are ALWAYS diploid.
Sympathetic NS is?
Parasympathetic NS is?
Sympathetic - fight or flight
Parasympathetic - rest or digest
What happens when Sympathetic NS is activated? (4)
- (1) Pupils dilate
- (2) Blood is directed away from digestive system to skin & muscles
- (3) Heart beats faster and more forcefully
- (4) Bronchi of lungs relax to let in more air
What is the Hardy Weinberg Equation?
Gene frequencies will not change over time and the frequencies in the next generation will be p2 for the AA genotype, 2pq for the Aa genotype and q2 for the aa genotype.
What happens during:
1. Prophase - 5
2. Metaphase - 2
3. Anaphase - 3
4. Telophase - 5
5. Cytokinesis - 2
- 1. Prophase - nuclear membrane disintegrates, nucleolus disappears, chromosomes condense/appear, mitotic spindles (microtubules) form b/t poles; kinetochores mature and attach to spindles.
- 2. Metaphase - chromosomes attach to mitotic spindles at kinetochores and align along metaphase plate at equator
- 3. Anaphase - kinetochore microtubules shorten, separating chromosomes to opposite poles, polar microtubules/cell elongate
- 4.Telophase - chromosomes reach poles of cell. Polar microtubules
- continue elongate. Nuclear membranes form, nucleoli reappear and
- chromosomes decondense.
- 5. Cytokinesis - cleave furrow forms and cell divides.
What are unique features of mitosis? (3)
What's formed after meiosis II?
Synapsis - after DNA replication and formation of sister chromatids --> forming of homologous chromosomes
Homologous recombination - genetic exchange between homologous chromosomes ("crossing over")
Reduction division - at the end of meiosis, each cell contains only half of original complement of chromosomes.
Sister chromatids in meiosis II aren't always identical. After meiosis II, haploid gametes formed.
What is the product of mitosis vs meiosis?
Meiosis - 4 haploid gametes
Mitosis - 2 diploid cells
What transition metals have fixed oxidation numbers? (4)
- Al = 3+
- Zn = 2+
- Cd = 2+
- Ag = 1+
In electrochemical cells, which direction do electrons flow?
Electrons always flow from anode to cathode.
Describe each stage of division in meiosis (3) and whether the cell is diploid or haploid and its n number.
How many times do chromosomes duplicate in meiosis?
only once! then followed by two successive divisions
Where is there no net diffusion of O2 and PO2?
Venous side of pulmonary capillaries (because PO2 in blood = PO2 in alveoli; same with CO2)
Venous side of tissue capillaries (b/c PO2 in tissue capillaries = PO2 in blood; same with CO2)
4 different forms of sperm; type of division; diploid/haploid; where it takes place
(1) Spermatogonia (2n) divides by mitosis into a spermatogonium & one primary spermatocyte.
(2) Primary spermatocyte divides by meiosis to form secondary spermatocytes
(3) secondary spermatocytes divide by meiosis again to form spermatids (n)
(4) Spermatids differentiate into sperm cells.
In Seminiferous tubules
What is the general rule of thumb for organic compound acidity? (9)
Strong acids > C.A. > Phenols > Alcohols/Water > alpha Hs on carbonyls > sp hybridized CH bonds > sp2 > sp3 hybridized CH bonds.
What are the Mark additions to alkenes?
(1) HX (Cl, Br, I): Racemic mix OR C+ rearrangement
(2) H2SO4, H2O: C+ R
(3) Oxymercuration, Hydroboration (1. Hg(OAc)2 + H2O/THF; 2. NABH/OH-) NO C+ rearrangement
What are the anti-mark addition to alkenes?
(1) Hydroboration (1. BH3 or B2H6; 2. H2O2/-OH) anti-mark alcohol; syn addition!!
(2) HBR addition with peroxides: Halogenated anti-mark alkanes - works only for HBr
Name the 3 Mark additions and 2 anti-mark additions.
Mark vs anti-mark
Mark: halogenation (racemic/C+), acid-catalyzed hydration (C+), and oxymercuration hydroboration (No C+).
Anti-Mark: Hydroboration (anti-mark ROH; syn); HBr addition with peroxides (works only for HBr)
- Mark: H adds to least substituted C
- Anti-Mark: H adds to most substituted C
Types of hydrogenation of hydrocarbons:
(1) H2 + metal --> reduces all pi bonds to alkanes
(2) Lindlar catalyst (H2, CaCO3 or BaSO4, Pd) --> alkyne to syn alkene
(3) Na, NH3 (l) --> alkyne to anti (trans) alkene
What is the criteria for a compound to be aromatic?
- 1. 4n + 2 pi electrons
- 2. overlapping p orbitals
- 3. flat & planar
- 4. cyclic
What are the organs involved in the immune system? (5) What do those outside of lymph system do?
Lymph vessels & lymph nodes
Bone marrow - produces immune cells like lymphocytes, monocytes, leukocytes, B cells and T cells.
Thymus - secretes thymosin which stimulates pre-T cells to mature
Spleen - storage area for blood; filters blood/lymph
What are 4 organs of the body that provide nonspecific immune defenses? What do they do?
- 1. Eyes - produce antibacterial tears lysozyme
- 2. Skin - important barrier; also regulates body temp and excretes excess water and salt.
- 3. Stomach - HCl kills bacteria
- 4. Mucus & Cilia push bad stuff out by coughing
What are additional nonspecific defenses: namely, what does the body secrete to fight: (1) infectious agents (2) viral infections (3) cellular damage?
- 1. Phagocytes (WBC) like neutrophils and macrophages
- 2. Interferons - stimulate protein production that interferes with viral replication.
- 3. Inflammatory response (injured cells release histamine blood vessels dilate, increased blood flow to site of damage).
- Fever too.
What are the 3 types of T cells? What do they do?
1. Cytotoxic T cells - kill cells that are infected by a pathogen that the T cell recognizes.
2. Helper - coordinate immune response of other cells against specific antigens through secretion of signaling molecules called lymphokines (interleukins)
3. Suppresor - regulate other T & B cells to decerase activity.
What do B cells do?
B cells respond to antigens (things that immune system recognizes as foreign) by making antibodies ("immunoglobins") that bind to antigens.
Antibodies mark the stuff that's supposed to be eaten by macrophages.
How do T cells recognize antigens?
T cells have T cell receptors on membranes of T cells.
T cells only recognize antigens that are on surface of other cells
To stimulate T cell, antigen must be presented to cell as part of a bunch of proteins called MHC (Major histocompatibility complex)
What are the two types of MHC?
- MHC Class I - present on surface of all cells
- MHC Class II - present only on immune cells (macrophages, B cells & T cells)
How are antibodies ultimately secreted? Starting with phagocytization of the pathogen.
1. Macrophages phagocytize a pathogen and bacterial proteins are broken down and displayed on surface of macrophage via MHC Class II.
2. Helper T cells recognize MHC-antigen complex on surface of macrophage and secrete interleukins
3. Interleukins activate cytotoxic T cells to kill infected cells & stimulate B cells to secete antibodies.
What is the purpose of interleukins (2)? Where are they secreted from?
Secreted from Helper T cells after HT cells have recognized MHC-Antigen complex on surface of macrophage.
Purpose: (1) activate cytotoxic T cells to kill infected cells & (2) stimulate B cells to secrete antibodies.
What are the two responses of the immunological memory system? What is this ability called? What cells is this based upon?
Primary immune response (first exposure to antigen)
Secondary immune response (exposed again to same antigen --> responds more quickly & effectively)
Memory cells - produced during the primary immune response. Memory cells survive for long periods and quickly proliferate if exposed to antigen that caused their creation.
When are memory cells created?
During primary immune response
What is the only type of naturally acquired immunity?
mother to fetus
1. Who destroys infected cells/cancer cells?
2. Who activates B & T cells?
3. Who produces antibodies?
4. Who regulates activity of B & T cells?
5. Who can become memory cells?
6. What do antibodies do?
1. Cytotoxic T cells
2. Helper T Cells
3. B cells
4. Supressor T cells
5. B cells
6. Antibodies mark antigens so macrophages can recognize them and eat them.
Compared to the bones of an adult, the bones of a growing child should:
Show areas of cartilage in the long bones (bc embryonic skeletal system is mostly cartilage).
ALSO - b.c epiphyseal plate is composed of cartilage and is site of longitudinal bone growth.
Why do children have more Haversian canals than adults?
they don't hehe tricked
Which of the following is true about activated B cells?
I. Act B cells contain more Rough ER than activated T cells.
II. Activated B cells contain more lysosomes than activated T cells
III. Activated B cells contain no nucleus
Macrophages definitely have more lysosomes than activated B cells.
Activated B cells do have nuclei too.
To keep a balance beam level, what must be zero?
TORQUE, force doesn't have to be zero, because it can move back and forth, side to side, without anything spilling over.
If someone's beating a drum and another person sprinkles fine sand on
the surface of the drum, what will the regions of localized sand
indicate?Where would there likely be no sand?
The circular nodes and diameter nodes. It's at the nodes where no vibration occurs, so that's where sand accumulates. At the antinodes.
How does a high or low pressure environment affect the pitch of an ideal membrane?
What factors determine pitch?
What factors determine speed of sound?
The pitch will remain unchanged because the frequency of vibration is not changed.
Frequency of vibration of membrane determines of frequency of pressure waves in air, determining the pitch of the sound detected.
Pressure & air density (low pressure & low air density = faster sound). But these factors DO NOT affect frequency of sound (pitch).
What should you automatically think when you see beat frequency?
When are frequency beats produced?
If there's a high frequency of beats, what can you infer?
Freq beats = Freq1-Freq2
If there's a high frequency of beats, that means that there is a large difference between the relative frequencies of the two sounds.
How to determine the hybridization of some made up molecule AB9?
Max velocity of swinging pendulum?
How does an impure solution's vapor pressure & BP compare to a pure solution's?
An impure solution would have lower vapor pressure and higher BP.
If a molecule has zero lone pairs, what are its possible shapes? (for 2 bonding electrons up to 6 bonding electrons)
- For zero lone pairs:
- 2 - linear
- 3 - trigonal planar
- 4 - tetrahedral
- 5 - trigonal bipyrimidal
- 6 - octahedral
If a molecule has one lone pair, what are its possible shapes? (2-5 bonding electrons)
For one lone pair:
2 - bent; 3 - trigonal pyramid; 4 - see saw; 5 - square pyramid
For 2 lone pairs, what are the possible shapes for electronic geometry?
2 - bent; 3 - Tshaped; 4 - Square planar
What does it mean if a falling object reaches a constant velocity before hitting the ground?
It means there's air resistance to factor in; so mass IS a factor.
At what angle above the horizontal should a projectile be fired to maximize the range before it hits the ground?
Define end point
The endpoint of a titration is the pH at which the indicator remains permanently at its end color.
What are the five laws of the kinetic theory of gases?
1. Gases are made of particles whose volumes are negligible compared to the container volume.
2. Gas particles have no intermolecular forces b/t each other
3. Gas particles are in continuous, random motion undergoing collisions with other particles & container walls
4. Collisions are ELASTIC, no overall gain or loss of energy
5. The absolute KE of an individual gas particle is proportional to the average temp of the gas and is the same for all gases at a given temp.
A sound wave oscillates in a pipe of length L. One end of the pipe is open and the other is closed. What is the formula for the wavelength of the sound wave?
wavelength = 4L/n; n = 1,2,3 etc.
Normally, for two open sides it would be wavelength = 2L/n; n = any integer
What will happen if you transfer a mitochondria in soln at pH = 8 until saturation to a second solution of pH 4 containing ADP and Pi?
Burst of ATP production
B/c at pH = 8 until saturation, this means that the mitochondria will be slightly basic throughout - decrease in H+ concentration. When mitochondria are transferred to an acidic solution, the medium outside the inner membrane will be acidic while the matrix will still be basic - perfect conditions for proton gradient to produce ATP.
What is needed to make ATP?
ADP and Pi
When a question asks which molecule is the most hygroscopic, what should you think?
Which molecule is most reactive with water? Look for acyl halides, anhydrides, etc.
What are the five tenets of the Hardy Weinberg equation?
- 1. The population must be very large in size.
- 2. Random mating
- 3. It must be isolated from other populations. (no gene flow)
- 4. No mutations
- 5. No natural selection.
What's the decimal value of 1/6 and 1/9?
1/6 = 0.167; 1/9 = 0.111
What's the decimal value of 1/7 and 1/11?
What's the decimal value of 1/8? 1/16?