Term
modern microscopes offer both higher __ and higher ___
- ___: measured in distance between two points that can be discriminated as distinct points
- __: measured in X-enlargement |
|
Definition
magnification; resoultion
- resolution
- magnification |
|
|
Term
___: light diffracted through series of glass lenses to produce magnified image
- light path:
- d= |
|
Definition
light microscopy
- 1. condenser lens 2. speciman 3. objective lens 4.ocular lens 5. eye or viewing screen
- d= .61lambda/n sin alpha |
|
|
Term
| modern microscopes have lenses with ___ |
|
Definition
| higher NA (light gathering ability) |
|
|
Term
| a shorter lambda causes ___; while a increased n sin alpha causes ___ |
|
Definition
| less scatter; increased numerical aperture |
|
|
Term
electron microscopy allows increased ___ and ___
- __ same but higher __ with electron microscopy |
|
Definition
magnification; resolution
- magnification; resolution |
|
|
Term
electron microscopy
- uses beam of __ instead of beam of light
- increased resolution by ___ of electrons through ___
- ___ used to focus electron beam in magnification (__)
- speciman coated with __ to get better ___ |
|
Definition
- electrons
- reducing wavelength; acceleration (voltage applied)
- electromagnets (current applied)
- heavy metals; diffraction of electrons |
|
|
Term
for a light microscope
- minimum ___, ___
- maximum mag = ___
- maximum res = ___ |
|
Definition
- light, wavelength fixed
- 1000x na
- 0.2 micrometers |
|
|
Term
for an electron microscope
- __ determines __
- maximum mag = ___
- maximum res = ___ |
|
Definition
- electron velocity determines wavelength
- 250,000 x
- .001 micrometers |
|
|
Term
___ gives even higher resolution
- is __ higher than em |
|
Definition
|
|
Term
epi-fluorescence microscope
- uses ___ that excites ___ label on specific molecule
- ___ allows only light of ___ of probe to reach specimen
- ___ allows only light of ___ of probe to reach eyepiece |
|
Definition
- single light wavelength; fluorescent
- excitation filter; excitation wavelength
- barrier filter; emission wavelength |
|
|
Term
how is a specific protein recognized in epifluorescence microscopy
1) fluorescence microscopy of ___ labeled protein
- the specific protein is expressed in __, purified, and ___ to fluorescent molecule ___ before it is injected into a living cell |
|
Definition
1) in vitro
- bacteria; covalently linked; in vitro (in test tube) |
|
|
Term
how is a specific protein recognized in epifluorescence microscopy
2) immunofluorescence microscopy
- uses a fluorescently labeled ___ that recognizes the specific ___ is used to indirectly label the protein in a fixed specimen |
|
Definition
|
|
Term
how is a specific protein recognized in epifluorescence microscopy
3) GFP tagging
- express the protein as a ___ in a living cell |
|
Definition
| 3) GFP (green fluorescent protein) - fusion protein |
|
|
Term
method 1: epifluorescence microscopy of in vitro labeled protein
- fluorescently labeled __ injected into __ |
|
Definition
|
|
Term
method 2: immunofluorescence microscopy
- fluorescently labeled ___ used to indirectly label protein in fixed cell |
|
Definition
|
|
Term
method 2: immunofluorescence microscopy
- fluorescently labeled ___ used to indirectly label protein in fixed cell |
|
Definition
|
|
Term
what are antibodies?
- they are __ expressed by ___ of vertebrate immune system
- they ___ with high specificity in immune response |
|
Definition
- proteins; B (plasma) cells
- bind foreign molecules |
|
|
Term
Method 3: GFP tagging
- GFP from jellyfish can be fused to __ and ____
- in GFP tagging, a gene fused from ___ is inserted into ___, and the __ is expressed in a living cell |
|
Definition
- any protein; expressed in almost any cell
- acting coding sequence DNA and GFP coding sequence DNA; genome of cell; protein |
|
|
Term
| what are the four types of macromolecules in cells |
|
Definition
| proteins, carbohydrates, lipids, nucleic acids |
|
|
Term
| magnification = ___ x ___ |
|
Definition
| objective lens x ocular lens |
|
|
Term
___: cell work horse
___: energy source
___: energy source and membrane
___: heredity |
|
Definition
protein
carbohydrate
lipids
nucleic acids |
|
|
Term
| a lower d number equals ____ |
|
Definition
|
|
Term
-genetic info usually contained in ___
-a virus consists of a ___ enclosed by __
-- __ required for it to be an infectious agent |
|
Definition
- nucleic acid (DNA or sometimes RNA)
- nucleic acid; protein coat
-- Viral nucleic acid |
|
|
Term
mad cow disease
- an infectious agent that is not a __, but a ___ |
|
Definition
|
|
Term
pron
- ingested protein is ___ and forms __ in brain, causing __
- improperly folded __ protein infects folding of normal cellular __ protein
- ___PrP^c: encoding gene cause similar disease
- __ also thought to be caused by improperly folded protein |
|
Definition
- improperly folded; aggregates; neurological defects
- PrP^sc; PrP^c
- mutations
- alzheimer's disease |
|
|
Term
basic chemistry review
- organic molecules characterized by __
- __: pairs of electrons shared between atoms
- #bonds an atom can form = ___ |
|
Definition
- covalent bonds
- covalent bonds
- # electrons required to fill outer shell |
|
|
Term
___: electrons shared equally between atoms
___: electrons shared unequally between atoms |
|
Definition
|
|
Term
___: electrons shared equally between atoms
___: electrons shared unequally between atoms |
|
Definition
|
|
Term
| an electronegative atom contains a __ which exerts __ on __ |
|
Definition
| positively charged nucleus; large attractive force; outer shell electrons |
|
|
Term
| an electropositive atom contains a ___ and exerts a ___ on ___ |
|
Definition
| less positively charged nucleus; smaller attractive force; outer shell electrons |
|
|
Term
| electronegativity is dependent on __ and __ |
|
Definition
| number of protons; distance between protons and outer shell electrons |
|
|
Term
| oxygen is very __ relative to hydrogen, but carbon and hydrogen have similar __, making molecules composed of carbon and hydrogen relatively __ |
|
Definition
| electronegative; electronegativities; nonpolar |
|
|
Term
| in addition to carbon and hydrogen, organic molecules contain __, with one or more ___ |
|
Definition
| functional groups; electronegative atoms |
|
|
Term
Bond types in macromolecules
- remember that covalent bonds have __ while non-covalent bonds have ___
- interactions between polar molecules include __ and __
- interactions between nonpolar molecules include __ and __
- Covalent bonds form the __; non-covalent bonds determine their __ and their ___ |
|
Definition
- equal sharing; unequal sharing
- ionic bond (3-7 kcal/mol); hydrogen bond (<3-7kcal/mol)
- van der Waals (1kcal/mol); hydrophobic interactions (<1kcal/mol)
- backbones of organic molecules; 3-D structures; interactions with other molecules in the cell |
|
|
Term
| proteins are constructed of __ building blocks |
|
Definition
|
|
Term
- primary level of protein structure: array of ___
- __ and __ form covalent protein backbone. __ will give unique 2d and 3d folding and functional properties |
|
Definition
- amino acids
- peptide bonds; C-C(alpha); R groups |
|
|
Term
| amino acids that are polar charged include: |
|
Definition
aspartic acid (Asp or D)
Glutamic Acid (Glu or E)
Lysine (Lys or K)
Arginine (Arg or R)
Histidine (His or H) |
|
|
Term
| amino acids that are polar uncharged include: |
|
Definition
Serine (Ser or S)
Threonine (Thr or T)
Glutamine (Gln or Q)
Asparagine (Asn or N)
Tyrosine (Tyr or Y) |
|
|
Term
| amino acids that are nonpolar include: |
|
Definition
Alanine: Ala or A
Valine: Val or V
Leucine: Leu or L
Isoleucine: Ile or I
Methionine: Met or M
Phenylalanine: Phe or F
Tryptophan: Trp or W |
|
|
Term
| side chains with unique properties include: |
|
Definition
Glycine: Gly or G
Cysteine: Cys or C
Proline: Pro or P |
|
|
Term
| R groups participate in specific __ types that drive __ |
|
Definition
| non-covalent bond; protein folding |
|
|
Term
__: extreme unequal electron sharing
__: electron shared between electropositive H atom and 2 electronegative atoms |
|
Definition
|
|
Term
| when seeing a picture of a protein, the spirals are the __ while the arrow are the ___ |
|
Definition
|
|
Term
ionic bond
- strongly __ COMPLETELY CAPTURE electrons from strongly ___
- __: atom attracting extra electron
- __: atom losing electron
- an ionic bond is strong when ___ and weak when __ |
|
Definition
- electronegative atoms; electropositive atoms
- anion
- cation
- buried deep in large macromolecule; on surface and exposed to H2O |
|
|
Term
R groups participate in specific ___ bond types that drive ___
- some R groups can form ___
- Which R groups can form ionic bonds? which are cations and anions? |
|
Definition
non-covalent; protein folding
- ionic bonds
- the polar charged amino acids can form ionic bonds; aspartic acid and glutamic acid are anions; lysine, arginine, and histidine are cations |
|
|
Term
polar charged r groups have both __ and __ forms in H2O (can either __ or __ H+ to/from H2O)
- a weak acid has a __ while a strong acid has a __ |
|
Definition
acid; base (donate;accept)
- stronger conjugate base; weaker conjugate base |
|
|
Term
a hydrogen bond is when a hydrogen atom is shared between two ___
- which R groups for hydrogen bonds |
|
Definition
electronegative atoms
- polar uncharged |
|
|
Term
| atoms of the __ bonds __ to form common __ |
|
Definition
| peptide; hydrogen bond; 2nd degree structural motifs |
|
|
Term
common structural 2nd degree motifs include __ and __
- in __, hydrogen bonding between __
- in __, hydrogen bonding between __ |
|
Definition
alpha helix; beta sheet
- alpha helix; turns of helix
- beta sheet; strands of sheet |
|
|
Term
alpha helix and beta sheet formed through __ between atoms of __
- peptide bond happens between __ and __ |
|
Definition
hydrogen bonding; peptide bond
- amine of one amino acid; carboxylic carbon of another amino acid |
|
|
Term
nonpolar functional group =
polar groups:
hydroxyl =
carboxyl =
amino =
phosphate =
carbonyl =
sulfhydryl = |
|
Definition
methyl ch3
oh
cooh
nh2
pohoh
co
sh |
|
|
Term
- there are __ between atoms of __ in ___
- there are __ between atoms of __ in __ |
|
Definition
-hydrogen bonds; peptide bond; adjacent strands of beta sheet
- hydrogen bonds; peptide bond; adjacent turns of helix |
|
|
Term
__: between momentary partial charges
__: aggregation of nonpolar molecules away from polar H2O |
|
Definition
van der waals interactions
hydrophobic interactions |
|
|
Term
| van der waals interactions happen between __ on ___ |
|
Definition
| momentary partial charges; non-polar meolecules |
|
|
Term
___ DRIVE TERTIARY LEVEL OF FOLDING
- H2O forms __ around __
- __ molecules aggregate to __
- overall ___ increases in ___ |
|
Definition
hydrophibic interactions
- ordered cage; polar hydrophilic molecules
- hydrophobic; avoid interacting with H2O
- entropy (disorder); surrounding H2O |
|
|
Term
X-ray diffraction shows that __ drive protein tertiary level of folding
- surrounding __ forces __ to ___ |
|
Definition
hydrophobic interactions
- H2O; hydrophobic residues; protein interior |
|
|
Term
| which R groups participate in Van der Waals and Hydrophobic interactions? |
|
Definition
| nonpolar grouping and glycine and proline |
|
|
Term
Reminder
- __ also affects ability of Polar R groups to ___
- H2O can ALSO either __ or __ |
|
Definition
- H2O; ionize (by donating H+ to H2O)
- donate; accept H+ |
|
|
Term
titration curves for organic molecules
- the pK' occurs at the ___ of a titration
- pK' = ____
- pK' reflects the strength of the __ relative to ___ |
|
Definition
- midpoint
- pH at which [c.acid] = [c. base]
- conjugate base; H2O |
|
|
Term
| - the pK' of a polar charged amino acid R group determines its __ at a given __ |
|
Definition
|
|
Term
__ = pH at which [acid] = [base]
- soluble acid/base pairs in solution can __, ___ from ionizing effects of __
- works best at ___ |
|
Definition
pK'
- buffer; polar charged groups; H2O
- pH = pK' |
|
|
Term
energy transformations in living organisms
- energy flows from __ to __ to __
- light used to make ___
- 3 energy transformations in cells
1.
2.
3. |
|
Definition
- light; photosynthetic organisms; respiring organisms
- high energy C source
1. light to chemical
2. chemical to chemical (C source to ATP)
3. chemical to mechanical |
|
|
Term
Laws of thermodynamics
1. ___ can neither be ___
2. all events in the universe tend to proceed _____, because some energy is __ in as a result of the tendency for __ to increase with each energy change
- gibbs free energy formula |
|
Definition
1. energy; created nor destroyed
2. downhill from a state of high energy to a state of low energy; always lost; disorder
- G = H - TS |
|
|
Term
G = ___
H = ___
S = ___
- for a reaction to occur ____ |
|
Definition
G - work energy
H - potential energy (enthalpy) in bonds
S - energy lost to heat or disorder (entropy)
- delta G must be < 0 (delta H<0 and delta S>0) |
|
|
Term
Natural tendency is for __ to increase
- energy required to ___ |
|
Definition
|
|
Term
combo of first and second laws
- the energy of the universe is __, but __ continues toward a maximum |
|
Definition
| - finite; entropy (disorder) |
|
|
Term
- an exergonic reaction occurs when __, and is termed ___
- an endergonic reaction occurs when __, and is termed ___ |
|
Definition
- delta G<0 ; spontaneous
- delta G>0 ; not spontaneous |
|
|
Term
- a reaction is spontaneous when __ and __
or __ and __, or __ and __ |
|
Definition
| delta H<0; delta S>0; delta H<<<0; delta S<=0;delta H=>0; delta S>>>>0; |
|
|
Term
-when delta H<0, the __ of __ is less than that of __
- when delta S>0, the __ of __ is greater than that of __ |
|
Definition
- bond energy; products; reactants
- disorder; products; reactants |
|
|
Term
what is enthalpy
- the __ when energy is released or needed to form
- the __ of two atoms, as well as __, contribute to strength |
|
Definition
- bond energy
- electronegativity; geometry of bond |
|
|
Term
| what is the difference between delta G, and delta G degree? |
|
Definition
| delta G predicts under nonstandard conditions, while delta G degree predicts spontaneity of reaction under standard conditions |
|
|
Term
delta G and delta G degree
- __ in cells are not standard
- delta G = |
|
Definition
- reaction conditions
- delta G degree + 2.303 RT log [C][D]/[A][B] |
|
|
Term
mechanisms used by cells to force endergonic reaction
1) altering ratio of ___
- if __ < __, than __ decreases
- [product] maintained low by serving as __ in ___ |
|
Definition
1) products to reactiants
- ratio; 1; delta G
- reactant; following more exergonic reaction |
|
|
Term
mechanisms used by cells to force endergonic reaction
2. coupling __ with __
- coupling to __ is very common |
|
Definition
2. endergonic reactions; exergonic reactions
- hydrolysis |
|
|
Term
enzymes speed up the rate of an __ in either the __ or __ directions
- enzymes change the __, but not the __ |
|
Definition
energy transformation; forward; backward
- kinetics (speed); thermodynamics |
|
|
Term
- __ happens at less than pK'
- ___ happens at more than pK' |
|
Definition
- acid (protonated)
- base (deprotonated) |
|
|
Term
rate of reaction depends on __ with sufficient __ to overcome ___
- enzymes lower ___ |
|
Definition
- number of reactants; kinetic energy; activation energy barrier
- activation energy barrier |
|
|
Term
how do enzymes accelerate chemical reactions
- multiple __ brought together in correct __ to catalyze reaction
- substrate influenced by __ at active site that alter __
- enzyme changes __ to bring closer to __ |
|
Definition
- substrates; orientation
- amino acids of side chains; chemical properties of substrate
- conformation of substrate; conformation of transition state |
|
|
Term
enzymes alter the __ of reaction at given __
- maximum speed of reaction is __
- substrate concentration needed to operate linearly is __
- the __ is linearly dependent on [S] |
|
Definition
velocity (speed); [substrate]
- Vmax
- Km
- intial reaction velocity Vo |
|
|
Term
graph
- difficult to decide where V=Vmax, but __
- Km = __
- Michaelis Menten Equation = |
|
Definition
- V=Vmax when [S]>>>>Km
- 0.5 Vmax at [S]
- V = Vmax x [S]/([S]+Km) |
|
|
Term
rearrangement to y=mx+b gives:
- y intercept =
- x intercept = |
|
Definition
1/Vo = (Km/Vmax)(1/[S]) + 1/Vmax
- 1/Vmax
- -1/Km |
|
|
Term
Competitive enzyme inhibitors
- affect __, not __
- compete with __ for __
- can be overcome by __ |
|
Definition
- Km, Vmax
- substrate; active site
- increasing substrate/inhibitor ration |
|
|
Term
noncompetitive enzyme inhibitors
- affect __, not __
- do not compete with __ for __, act at __
- cannot be overcome by __ |
|
Definition
- Vmax; Km
- substrate; active site; different site on enzyme
- substrate/inhibitor ratio |
|
|
Term
michaelis-menten plot
- noncompetitive reduces __, does not affect __
- competitive increases __, does not affect __ |
|
Definition
|
|
Term
formula for glycolysis
- delta G is __ |
|
Definition
c6h12o6 +6o2 > 6co2 +6h2o
- negative |
|
|
Term
__ is the buildup of molecules
- __ and requires energy input (ATP)
- __ in absence of ATP |
|
Definition
anabolism
- delta S<0
- delta H>0 |
|
|
Term
__ is the breakdown of molecules
- __ does not require energy input
- __ sufficient to make ATP |
|
Definition
catabolism
- delta S>0
- delta H<0 |
|
|
Term
catabolism involves __ of reduced hydrocarbonds
- electron is stripped from C and transferred to __ to generate __ that drives __ |
|
Definition
oxidation
- ETS; H+ gradient; ATP synthase |
|
|
Term
Energy extracted from glucose is used to make __
- __ is not the highest energy containing molecules in the cell |
|
Definition
|
|
Term
Aerobic respiration
- begins with __ in __ which yields __
- finishes in __ to make ___ |
|
Definition
- glycolysis; cytoplasm; 2 ATP
- mitochondria; ~30 more ATP (cell type dependent) |
|
|
Term
details of glucose oxidation (glycolysis)
- formula:
- the atp is created by __ |
|
Definition
- glucose + 2ADP + 2 Pi + NAD+ > 2 Pyruvate + 2 ATP + 2NADH
- substrate level phosphorlyation |
|
|
Term
citric acid cycle (TCA)
- takes place in the __
- formula: |
|
Definition
- matrix of mitochondria (innermost)
- (2 AcetylCoA + 6 NAD + 2 FAD + 2 ADP + 2Pi -->
4 CO2 + 6 NADH + 2 FADH2 + 2 ATP + 2 CoA + heat) |
|
|
Term
TCA cycle is the entry point for __ of other carbon energy sources
- __ is quicker |
|
Definition
|
|
Term
mitochondrion
- outer and inner membranes with many folds (cristae) divides into __ and __
- allows __ to be established across __, used to drive __ activity |
|
Definition
- matrix; intermembrane space
- H+ gradient; inner mitochondrial membrane; atp synthase |
|
|
Term
how is the H+ gradient made
- transfer of high energy e- from __ to __
- transfer of high energy e- from __ to __ embedded in __
- energy released from electron transport used to __ from __ to __
- flow of __ back through __ powers its activity |
|
Definition
- glucose; NADH/FADH2
- NADH/FADH2; electron carriers; inner mitochondiral membrane
- pump H+; matrix; intermembrane space
- H+; atp synthase |
|
|
Term
electron carriers include __ and __
- __ accepts both protons and electrons
- __ accepts electrons only |
|
Definition
flavoproteins; cytochromes
- flavoproteins
- cytochromes |
|
|
Term
electron carriers
- flavoproteins contain __ prosthetic group FAD or FMN as __ center
- cytochromes contain __ prosthetic group as __ center |
|
Definition
- riboflavin; redox
- heme; redox |
|
|
Term
tendency to accept or donate electrons measured in ___
- this is directly proportional to tendency to accept ___
- high Eo means high tendency to __ and low tendency to __
- low Eo means low tendency to accept __ and high tendency to __ |
|
Definition
redox potential (Eo)
- electrons
- accept electrons; donate electrons
- electrons; donate electrons |
|
|
Term
when looking at standard redox potentials of selected half reactions
- the rule of thumb is that ___ |
|
Definition
| - electron flow always downward in chart |
|
|
Term
flow of electrons through electron transport chain
- sufficient energy for __ released in 3 steps
- energy released with __ |
|
Definition
- ATP synthesis
- transfer |
|
|
Term
energy released in 3 steps (complexes I, III and IV) sufficient to __
- __ yield when electrons transfer initiated by NADH
- __ yield when electron transfer by FADH2 |
|
Definition
pump H+ (will drive ATP synthase)
-3 ATP
- 2 ATP |
|
|
Term
H+ pumping from __ to __
- demonstrates H+ pumping capability of __
- __ are transferred to O2 to make H2O, but they are transferred ___
- __ are highly reactive - dangerous to cell |
|
Definition
matrix; intermembrane space
- cytochrome oxidase
- 4 electrons; one at a time
- single electrons |
|
|
Term
| __ is the cost of aerobic respiration |
|
Definition
|
|
Term
mitochondrion
- outer and inner membranes with many folds divides into __ and __
- mitochondrial genome inherited ___ |
|
Definition
- matrix; intermembrane space
- maternally only |
|
|
Term
genetic variation in the mitochondrial genome is correlated with __ in males, but not in females
- mitochondrial genome is __ inherited
- therefore, natural selection is only able to screen out deletarious mutations in __. mutations that reduce __ lifespan can accumulate, while those that reduce __ lifespan cannot |
|
Definition
aging phenotypes
- maternally (present in egg only)
- females; male; female |
|
|
Term
ATP synthase structure
- H+ translocation through __ drives __
- __ has catalytic activity
- __ attached to __ ring
-- rotation of __ and __ stimulates beta subunit
- __ H+ translocation activity |
|
Definition
- c ring; rotation
- head domain beta
- y; c
-- c; y
- stalk domain |
|
|
Term
atp synthase structure
- rotation of dial powered by ___ |
|
Definition
| - H+ flow instead of electricity |
|
|
Term
mechanism of ATP synthase action
1) rotation of __ and its attached __ relative to __ induces __ in beta subunits
2) beta subunit active sites progress successively through three distinct __ with three different affinities for each substrate and product
3) __ produced with each __ rotation of y subunit |
|
Definition
1) c subunit; y subunit; fixed beta subunits; conformational change
2) conformations (O, L, T)
3) 3 ATP; 360 degree |
|
|
Term
H+ translocation and c-ring rotation
- H+ picked up from __ through half channel open to __
- H+ binding to asp61 of c subunit causes ___
- full rotation of H+ allows ___ through half channel open to matrix
- __ translocated/__ made
- a-subunit entry/exit port open to __ |
|
Definition
- intermembrane space (IMS); IMS
- c ring rotation
- release into matrix space
- 12 H+ / 3 ATP
- IMS |
|
|
Term
| amino acids
- if pHpKa then __ |
|
Definition
- protonated
- deprotonated |
|
|
Term
evidence for rotation of c subunit
- entire __ attached to coverslip
- contains __, __ triple fusion protein
- observed rotation of __ filament propellor
- his tagged ___ |
|
Definition
- ATP synthase
- GFP-actin, C-ring
- GFP-labeled actin
- beta subunit |
|
|
Term
aerobic respiration in muscle
- aerobic is __ muscle fibers
- used in __ exercise
- __ phosphorylation
- __ and __
- much __ and __ supply |
|
Definition
- slow twitch
- endurance
- oxidative
- glucose and fatty acids
- mitochondria; oxygen |
|
|
Term
anaerobic respiration in muscle
- __ muscle fibers
- used in __ exercise
- less __ and __ supply
- __ phosphorylation
- __ and __ |
|
Definition
- fast twitch
- short bursts, high intensity
- mitochondria; oxygen
- substrate level
- fermentation and creatine stores |
|
|
Term
photosynthesis
- uses __ and __ to produce glucose
- H+ gradient formed across __ drives atp synthase
- __ needed to form p680+ (extracts e- from water) |
|
Definition
- co2; water
- thlakoid membrane
- light energy |
|
|
Term
aerobic respiration
- glucose broken down into __ and __
- H+ gradient formed across __ drives atp synthase
- __ has a higher redox potential than O2 |
|
Definition
- co2 and water
- mitochondrial inner membrane
- p680+ |
|
|
Term
active transport - bacteriorhodopsin
- __ driven H+ pump
- light induces change in __ of __
- H+ pumped into __ between inner and outer membrane
- H+ gradient drives __ |
|
Definition
- light energy
- electronic structure; retinal
- periplasmic space
- atp synthase |
|
|
Term
the structure and function of the plasma membrane
- lipids are __ molecules that have both polar and non-polar ends
- contains __ facing out, this is __
- contains __ facing in, this is __ |
|
Definition
- amphipathic
- hydrophilic head; polar
- hydrophobic tail; non-polar |
|
|
Term
history of membrane structure
- e overton discovered __ nature of plant root hair membrane
- membrane is __, __ ratio of lipid to H20 when spread out |
|
Definition
- nonpolar
- lipid bilayer; 2:1 |
|
|
Term
electron micrographs showed __ appearance of plasma membrane (gives high resolution)
- __ stains polar head groups only |
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Definition
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Term
__ is not strictly dependent on lipid solubility
- membrane often depicted by __
- membranes also contain __ and are __ structures |
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Definition
membrane permeability
- fluid mosaic model
- proteins; dynamic |
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Term
chemical composition of membranes
- lipid/protein assemblies held together in thin sheet by ___
- lipid bilayer provides ___
- protein carry out ___
- carbohydrates involved in __, and __
- __ varies between cell types and organelle types |
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Definition
- noncovalent bonds
- fluid structural framework
- specific functions of the membrane
- cell to cell interactions; protein anchoring and functions
- protein ratio |
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Term
lipid bilayer provides __ structural framework
- has ability to __ in aqueous solution
- contributes to its __ and __
- forms vast ___ networks |
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Definition
fluid
- self-assemble
- fluidity; flexibility
- interconnected membrane |
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Term
lipids can self-assemble into __ in aqueous solution
- __: self-assembled fluid filled membrane vesicle formed in vitro from phospholipids in aqueous solution
- serve as __ |
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Definition
lipid vesicles (liposomes)
- liposome
- drug delivery vehicle |
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Term
| phosphoglycerides: built on __ backbone, contain __ fatty acids and __ linked to __ |
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Definition
| glycerol; 2; phosphate group; OH |
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Term
| sphingolipids: __ with long __ tail linked to fatty acids through __ |
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Definition
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Term
membrane fluidity and temperature effects
- above transition temp (mp): __
- below transition temp: __ |
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Definition
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Term
cis double bonds and membrane fluidity
- single cis double bond ___
- gel at higher T:
- liquid at lower T:
- to increase membrane fluidity: |
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Definition
- lowers mp 60 C
- all c-c close packing
- C=C at crooks, loose packing
- desaturate single bonds, reshuffle phospholipids, alter phospholipid synthesis |
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Term
cholesterol
- __ than most lipids
- less __
-- __ -oh group toward exterior __ in lipid bilayer
- flat and rigid __ prevent close packing of lipids
-- __ fluidity at low concentration
-- __ fluidity at high concentratoin |
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Definition
- smaller
- amphipathic
-- hydrophilic; hydrophobic tail
- rings
-- increase
-- decrease |
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Term
cholesterol rich lipid rafts
- regions of high cholesterol have __
- sites of __ anchored signaling proteins
- surrounded by __
- important for __ |
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Definition
- low fluidity
- GPI (glycolipid)
- more fluid membrane (lower cholesterol)
- cell signaling |
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Term
high cholesterol
- reduces __ of surrounding phospholipid head groups on outer leaflet
- stiffens and reduces ___ |
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Definition
- lateral shift
- permeability |
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Term
Protein dynamics in membranes
- techniques used to demonstrate dynamic movement of proteins in membranes
-- cell fusion: tracks spread of __ throughout membrane of fused cell |
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Definition
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Term
Protein dynamics in membranes
- techniques used to demonstrate dynamic movement of proteins in membranes
- FRAP (fluorescence recovery after photobleaching): labeled protein diffuses into ___
-- method used to monitor dynamics of proteins in many __ not just __
-- short FRAP time: very __
-- long FRAP time: very __ |
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Definition
- bleached spot
-- cellular compartments; membranes
-- dynamic
-- static |
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Term
membrane proteins
- __: penetrate through lipid bilayer
- __: outside membrane but associated with cytoplasmic side through noncovalent bonds
- __: outside membrane but associated with either extracellular or cytoplasmic side through covalent bond |
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Definition
- integral
- peripheral
- lipid anchored |
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Term
__ and __ used to determine distribution of membrane proteins in lipid bilayer
- __: peel lipid bilayer apart to examine protein distribution in lipid bilayer
- __: labeled antibodies show distribution of protein at high resolution |
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Definition
immunoelectron microscopy; freeze fracture
- freeze fracture
- Immuno EM w/Gold |
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Term
freeze fracture replica
- rapid cell __
- coat fractured surface with __ stain
- __ cell and replica of cell surface remains |
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Definition
- freezing
- carbon/metal
- thaw |
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Term
identifying typical transmembrane domain of integral membrane protein from protein sequence
- string of 20-30 predominantly __ that form __
- __ used to predict transmembrane domain from sequence |
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Definition
- nonpolar amino acids; alpha helix
- hydropathy plot |
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Term
amphipathic helices in aqueous channel proteins
- contain alpha helix with __ in otherwise __
-- or one ___
-- polar amino acid every __ residue (one/helical turn every __ residues) |
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Definition
- one polar face; nonpolar helix
-- polar beta sheet rim
-- 3-4th (3.6) |
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Term
integral membrane protein (aquaporin) surrounded by a shell of __
- __: face lipid shell
- __: face aqueous channel |
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Definition
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Term
biochemical isolation of integral membrane proteins
- integral membrane proteins require solubilization in __ |
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Definition
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Term
movement of substances across cell membranes
- __: passive
- __: active |
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Definition
- delta G < 0
- delta G >0 |
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Term
Energy required to move a molecule across a membrane (in)
- formula:
- for uncharged species, only __ considered
-- formula:
- for charged species, __ and __ considered
-- formula: |
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Definition
- delta G = delta G degree + 2.303 RT log (product/reactant)
- concentration gradient
-- delta G = RT ln [Cin]/[Cout]
- concentration; charge gradient
-- delta G = RT ln [Cin]/[Cout] + zFE |
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Term
nonmediated passive diffusion - osmosis
- membranes are __
- H2O moves through them __ than dissolved ions or small polar solutes
- H2O moves from a region of __ to a region of __
- __: water moves in
- __: water moves out
- __: no net flow |
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Definition
- semipermeable
- small polar
- more rapidly
- hiher water concentration/lower solute concentration; lower water concentration/ higher solute concentration
- hypotonic
- hypertonic
- isotonic |
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Term
passive transport: transporter (carrier) mediated
- move molecules from a region of __ to a region of __
-- delta G is __
- two methods of gating
-- __: conformation depends on concentration of specific ligand
-- __: conformation depends on charge across membrane |
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Definition
- high concentration; low concentration
-- <0
-- ligand gated
-- voltage gated |
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Term
transporter faciliated diffusion - ligand gated
- localized on __ in response to __
- __ binds to transporter on __ side of membrane
- __ change triggered
- solute free to diffuse to __
- no __ required
- works equally in __
- mutant forms associated with __ |
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Definition
- plasma membrane; insulin
- solute (glucose); high glucose
- conformational
- low conc.
- energy
- both directions (depending on conc. gradient)
- diabetes type II |
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Term
transporter facilitated diffusion - voltage gated
Voltage Gated K+ channel:
- __ membrane spanning segments
- __ regulates opening
- __ charged residues distributed throughout __ act as __
- __ of membrane generates electric current through __ charged residues
- __ moves; allowing __ to freely flow out
- __ moves into pore to inactivate |
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Definition
- 6 (S1-S6)
- S4
- +; S4; voltage (charge) sensors
- depolarization; +
- S4 helix; K+
- ball domain |
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Term
transporter facilitated diffusion - voltage gated - experimental evidence
-FI probe on __ charged residues buried in membrane when __ inside cell (at rest)
- FI probe moves to surface when membrane __ |
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Definition
- +; excess -
- depolarized (increased + charge inside cell_ |
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Term
active transport - sodium/potassium pump
- transport coupled to ___
- required to maintain __ across membrane
- role in __ of nerve cell
- __: phosphorylated intmd.
- __ changes affinity and conformation
- __ ions pumped out and __ pumped in |
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Definition
- atp hydrolysis
- large concentration gradient
- resting potential
- p type pump
- PO4
- 3 NA+; 2K+ |
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Term
membrane potential
- measured with __
- at rest the sodium potassium pump establishes gradient of __ outside, __ inside the cell, and a net __ charge inside the cell |
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Definition
- voltmeter
- >>[Na+]; >[K+]; negative charge |
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Term
membrane potential
- at rest:
- depolarized:
- repolarized:
- ions flow through __ |
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Definition
- 3 Na out; 2 K in
- Na+ flows in
- K+ flows out
- ion channels (e.g. voltage gated K+ channels) |
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Term
the action potential - nerve impulse
- resting potential (~ __ mv): __ establishes ion gradient
- depolarizaion (__ flows in; __ mv) 2 steps
1. __ depolarization (-50mv)
2. __ depolarization (+50mv) all or none
- repolarization (__ flows out) (__mv)
-- voltage gated __ |
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Definition
- (-70mv); sodium potassium pump
- Na+; (+50mv)
-- threshold
-- full
- (K+); (-80mv)
-- K+ channel |
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Term
1. polarizes, __ establishes resting potential
2. depolarization, involves __ and __
3. repolarization involves __
- __ released from pre-synaptic neruon, regulate __; binding stimulates __ to __ |
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Definition
1. sodium potassium pump
2. neuroreceptor; voltage gated sodium channel
3. voltage gated potassium channel
- neurotransmitters; transmission; depolarization; threshold |
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Term
neurotransmitters regulate ___
- neurons connected to target cell at __
- __: narrow gap between the presynaptic cell and postsynaptic target cell
- neurotransmitters released from pre-synaptic neuron bind to postsynaptic membrane receptors to stimulate ___ |
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Definition
synaptic transmission
- synapse
- synaptic cleft
- Na+ channel opening |
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Term
2 steps in depolarization
1) __ gated Na+ channel depolarization to -50mv (__)
2) __ gated Na+ channel full depolarization to __mv |
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Definition
1) neurotransmitter; (threshold)
2) voltage; +50mv |
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Term
neurotransmitters cal also __ synaptic transmission
- neurotransmitters released from pre-synaptic neuron bind postsynaptic receptors to activate ___, which causes __ which is the opposite of __ |
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Definition
inhibit
- Cl- channel opening; hyperpolarization; depolarization |
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Term
all terminal knobs of given neuron release same neurotransmitter, but effect on postsynaptic membrane can be either __ or __
- effect of neurotransmitter at synaptic cleft must be __ so that post-synaptic membrane remains responsive |
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Definition
stimulatory; inhibitory
- short lived |
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Term
two mechanisms for removing from synaptic cleft
1. __: acetylcholine - inhibited by __
2. __: __ - inhibited by __ or __
__ - inhibited by __
- many diseases of nervous system rooted in __: myasthenia gravis, parkinson's, schizophrenia, depression |
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Definition
1. destruction; acetylcholine; nerve gas
2. reuptake; dopamine; cocaine; amphetamines; serotonin; prozac
- synaptic dysfunction |
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Term
- vertebrate axons wrapped in __ insulation
- action potentials only occur at ___
- propagation down axon is sped up, because rather than moving entire length of membrane, it can ___
- __: disease of myelin sheath deterioration |
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Definition
- myelin sheath
- unwrapped gaps (nodes of ranvier)
- jump from node to node (saltatory condcution) |
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Term
What regulates neurotransmitter release from pre-synaptic neuron?
- the propagation of the action potential down the axon stimulates opening of ___ in pre-synaptic knob. This stimulates fusion of __ with pre-synaptic membrane and release of neurotransmitter into the synaptic cleft. |
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Definition
| - voltage gated calcium channels; fusion of synaptic vesicles |
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Term
- voltage gated calcium channels are also stimulated to open at __
- calcium release into muscle cytosol stimulates __ |
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Definition
- neuromuscular junctions
- muscle contraction |
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Term
other active transporters
- __ of stomach lining pumps H+ into stomach against __ |
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Definition
| - sodium potassium pump; [H+] gradient |
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