test 4 review Flashcards
What is the equation for kinetic energy ?
KE= 1/2 mv^2
What happens to ratchet system (with blocks) if it is Frictionless? How does this impact Kinetic energy ?
If the rachet system is frictionless means that the height to which the block rises is taken to correspond completely to the kinetic energy of the block at the beginning of its swing (all of the final gravitational potential energy comes from all of the initial kinetic energy).
Thus assuming** NO friction means that the calculated muzzle velocity is LESS than the actual velocity** which gave the block enough initial kinetic energy both to reach the measured height h as well as to overcome the negative work done by friction.
What happens if a system has friction ? How is KE and velocity affected ?
However, if there were Friction, then that final height h would be due not only to the initial kinetic energy but also to the negative work done by friction.
**Reaching the same height h with friction thus requires more initial kinetic energy than reaching it without friction, and more kinetic energy implies a greater muzzle velocity.
What is the equation for conservation of mechanical energy ?
law of conservation of mechanical energy:
Change in KE= - change in PE (potential energy)
KEi + PEi = KE f + PE f
What is equation for non-conservative forces?
Non-conservative forces
Kei + PEi + Work done by nc = KEf + PEf
What are examples of non-conservative forces?
kinetic friction, drag
non-conservative forces do negative work and if they are doing work, mechanical energy NOT conserved
what are examples of conservative forces?
Spring force, electrostatic forces, and gravity, have potential energy associated with them.
-if these forces are doing work, than mechanical energy is conserved
What is the equation for change in potential energy ?
Change in PE: mg x change in height
What is the equation for elastic potential energy for compressed spring?
The elastic potential energy of the compressed spring,= 1/2)kx^2,
What is kinetic molecular theory ?
states that gases are in constant motion and have perfectly elastic collisions
What happens to molecules with intermolecular attractions ? How is PE and KE affected?
Intermolecular attractions Increase the potential energy (PE) between molecules, Decreasing their kinetic energy (KE ).
What is the periodic trend for atomic radius of elements F2, Cl2 and Br2 ?
Atomic size increases To left and DOWN,
hence F2 < Cl2 < Br2
(Br is largest)
What happens to polarizability, with increasing size and number of electrons? How does this affect LDFs ?
With increasing size and number of electrons comes a GREATER polarizability, which increases the strength of the element’s London dispersion forces.
What are the characteristics of facultative anaerobes ?
A facultative anaerobe can survive through fermentation when oxygen is not available, but will use oxidative respiration when oxygen is available.
Which process can undergo both aerobic and anaerobic conditions ?
Glycolysis
Glycolysis will occur under both aerobic conditions (in which case the pyruvate will go on to enter the Krebs cycle as acetyl-CoA) and under anaerobic conditions (fermentation reduces pyruvate to alcohol or lactate),
What process only occurs under anaerobic conditions ?
Fermentation
which processes can only occur under aerobic conditions ?
Krebs cycle and Oxidative phosphorylation
What is specific gravity ? What is the sp gr for water?
measure of density with respect to density of pure water?
sp gr H2O : 1 g/mL or 1000 kg/m^3
What is the first step of gluconeogenesis? Which enzyme ?
In the first step of gluconeogenesis, pyruvate is also converted into OAA (by the enzyme pyruvate carboxylase).
What reaction occurs with PEPCK (phosphoenol pyruvate carboxykinase) ?
OAA is converted into phosphoenolpyruvate (PEP) by the enzyme phosphoenolpyruvate carboxykinase (or PEPCK).
this occurs in gluconeogenesis
what will happen to glutamic and aspartic acid at physiological pH?
At physiological pH (about 7.4), both the carboxylic acid end of the amino acid and the side chain COOH will be DEPROTONATED. T
his is because physiological pH is above the pKa values for these acidic protons (carboxyl pKa is approximately 2, and the R-group pKa is approximately 4). Thus, aspartic acid will actually be in its aspartate form, and will have two deprotonated carboxylic acid groups at physiological pH
what happens to amino group side chains if pH is greater than pka?
PH > Pka, the amino acid will be deprotonated
What is the role of parietal cells? What does HCl do?
. Parietal cells are found in the stomach and are responsible for producing HCl, which causes the stomach contents to have a low pH. HCl also non-specifically digests proteins by cleaving peptide bonds, and activates pepsinogen.
What happens if parietal cells are elevated?
Elevated parietal cell secretions would mean more acid, and a lower gastric pH .
More acid would also lead to slightly more protein break down
What is Hooke’s Law equation ?
F = Kx
describe material being stretched, its change in length will be proportional to strength of force of elongation
What is the conjugate first rule?
the conjugate of a strong acid or strong base is pH neutral.
What his heat of neutralization ?
The heat of neutralization is defined as the enthalpy change resulting from 1 mole of water being produced from the reaction H+(aq) + OH–(aq) → H2O(l).
What happens to delta H (enthalpy) for weak acids like acetic acid?
Since weak acids (like acetic acid) are only partially ionized, there will be an additional endothermic step for the dissociation of the weak acid, decreasing the magnitude of ΔH for the overall reaction
What happens to temp for larger or smaller delta H (enthalpy) ?
If the ΔH is larger for an exothermic reaction, more energy will be given off, resulting in a larger increase in temperature
Similarly, if less energy is given off, the temperature change should be smaller
What are the properties of transmembrane domains?
Transmembrane domains are alpha-helices with external hydrophobic residues.
They cannot contain proline because of its secondary amine structure.
What is the slope of LineWeaver Burk plot
e slope of the Lineweaver-Burk plot is Km/Vmax,
What kind of inhibition will not affect slope of line weaver burk plot ?
UNCOMPETITIVE inhibition!! An uncompetitive inhibitor leads to an equal decrease in the both the Km and Vmax, leading to a series of parallel lines on a Lineweaver-Burk plot
Where does proton pumping of ETC (electron transport chain) occur?
protons are pumped from Mitochondrial matrix to inner membrane space
Where do prokaryotes pump H+
across PLASMA Membrane
where does beta oxidation occur compared to fatty acid synthesis ?
Beta oxidation (breakdown fatty acids) occurs in Mitochondrial matrix
fatty acid synthesis occurs in cytoplasm
Which factor determines K equilibrium?
The equilibrium constant, K, depends on the TEMPERATURE only. That is, the ratio of products to reactants (with the appropriate stoichiometric coefficients as exponents on the concentrations) at equilibrium will remain the same at a given temperature.
in kinetics, what does rate of overall reaction depend on?
rate of overall reaction depends on SLOW step of reaction
what is major rule about lewis structures ?
Once you recognize that the sum of the formal charges in the Lewis structure must be equal to the overall charge of the ion (in element)
hence only the structure in choice A satisfies this criterion.
compare and contrast kinetics and thermodynamics
The kinetics of any reaction can only affect the RATE of the reaction, while thermodynamics can only affect results based on STABILITY
what happens to alpha hydrogens and acid derivatives when bonded next to carbonyls?
All α-hydrogens to carbonyls or acid derivatives are weakly Acidic.
What does HPLC (High performance, liquid chromatography) do ?
allows for quantitative purification of a mixture based on differences in polarities of functional groups
How does the brain determine the location of the sound?
Sound waves reach the ear closest to the source of the sound first, and the further ear second. This time gap allows the brain to determine the location of the sound
What are the unique characteristics of Endoplasmic reticulum, phosphofructokinase, and Alanine?
The endoplasmic reticulum is an organelle with a single membrane surrounding a lumen
Phosphofructokinase is an enzyme of glycolysis, and so is a protein made of amino acids linked together by covalent peptide bonds.
Alanine is a chiral amino acid, and so has four different groups on a chiral alpha carbon
What does total internal reflection mean?
total internal reflection occurs when the angle of incidence is greater than the critical angle,
What does resistivity of a current-carrying component imply?
Resistivity of a current-carrying component immediately implies dissipation of heat
Where in the heart is systolic pressure 0?
-in RIGHT ATRIUM
Blood from the systemic circulation at the end of its circuit through the body enters the heart through the right atrium, and at this point its pressure is near 0 mm Hg
What part of The heart is systolic pressure the highest ?
AORTA
Blood leaves the heart through the aorta on its way to the systemic circulation and is at its highest pressure at that point. From the aorta the blood travels through many arteries, and the pressure in these vessels is still high
