BIO 140 FINAL Flashcards
covalent bond
sharing of electron pairs, strong, enzyme breaks it
isomer
diff geometric arrangements of same formula
non covalent
weak, broken by heat
polar covalent
unequal sharing of e- , hydrophilic, +/- partial charge
hydrogen bond
hydrogen attached to highly electronegative atom O . THERE IS HYDROGEN
of neutrons
calculated by subtracting the atomic number from the atomic mass; differentiates isotopes from same element
mass number
protons and neutrons
rows
same number of shells/ orbitals (rings)
columns
number of valence e- (1-8). SHOW MORE SIMILARITY group/family
higher H+
lower ph= acidic
lower H+
higher ph= basic
electronegative
exert greater force of shared e-, partial +/- POLAR COVALENT bond
non polar covalent
equally sharing of e-
ionic
metal and nonmetal, transfer/ donate electrons
oxygen
electronegative, polar covalent bond
hydrophobic
not dissolve in water, non-polar
hydrophilic
dissolve in water , polar
dissolve in water?
covalent( sugar) and ionic (salt)
van der walls
prortein- protein, weak, due to transiet aysmmetries
cell respiration
break down food for enegery to run
proteins
proteins are polymers made up of monomers, complex, made up of amino acids
nucleic acids
rna and dna
lipids
not polymers bc not made up of same structure HYDROPHOBIC
The discovery that DNA from killed virulent bacteria can transform live harmless bacteria, and therefore is the hereditary molecule, was based on the work of
Griffith/Avery, Macleod, and McCarthy
The leading and the lagging strands differ in that
the leading strand is synthesized in the same direction (5’-3’)as the movement of the replication fork, and the lagging is synthesized in the opposite direction(3’-5’)
what is the difference between the sugars moieties in DNA and RNA?
DNA contains deoxyribose which lacks a 2’ OH group
lipid types
fats/ oils= energy, sugars= signal/ structure, phospholipids= make up cell membranes
electronegativity
A measure of the ability of an atom in a chemical compound to attract electrons
if a double stranded DNA has 10% Guanine, what percent Adenine would be expected?
10% Guanine - 10% Cytosine = 20%
100/20 =80
80/2 = 40% Adenine & Thymine
a covalent bond is likely to be polar when
one of the atoms sharing electrons is more electronegative than the other
The DNA template is read in the _____ direction and mRNA synthesis occurs in the ______ direction
3’ to 5’ ; 5’ to 3’
Similarities and differences between eukaryotes and prokaryotes
-Similarities: plasma membrane, cytosol, DNA, ribosomes, cell wall (only in some eukaryotes and the structures are very different)
-Differences: presence of a nucleus (and other membrane bound organelles), size
First law of thermodynamics
energy cannot be created or destroyed (the total energy of a system remains constant)
Second law of Thermodynamics
the degree of disorder in the universe tends to increase over time
Explains the terms antiparallel and complementary as they relate to DNA and RNA structure
-Antiparallel- one strand runs 5’ to 3’ and the other runs 3’ to 5’
-Complementary- base pairing rules = A binds to T and G binds to C (purines bind with pyrimidines)
valenece electrons
number of electrons in outermost energy shell
micelles
A spherical structure in which lipids with bulky heads and a single hydrophobic tail are packed.
Exocytosis
when a vesicle fuses with the plasma membrane
Physiological pH is 7.4. What is the hydrogen ion concentration of a solution at
physiological pH?
a. -7.4
b. 0.6 x 10-8
c. 1 x 10-7.4
d. 4 x 10-8
c. 1 x 10-7.4
HOW TO SOLVE:
pH = -log [H+]
[H+] = 1x10-pH
[H+] = 1 x 10-7.4
unsaturated fatty acid
Having one or more double bonds that introduce kinks in the phospholipids reducing the tightness of packing
saturated fatty acids
no double bonds, resulting in phospholipids with a straight structure that favors tight packing
excision repair
corrects abnormal or damaged bases
mismatch repair
DNA containing the mismatch is removed then resynthesized
Hypertonic
one with higher solute concentration than that inside the cell (shrinks
Isotonic
when the concentration of two solutions is the same
hypotonic
Having a lower concentration of solute than another solution (moves into cell and bursts)
how does a lysosome maintain its low internal pH
by pumping hydrogen ions against their concentration gradient into the lysosome
lysosome
contains enzymes that break down macromolecules such as protons, lipids, and complex carbs
protein transporters that move in opposite directions.
antiporters
symporters/cotransporters
protein transporters that move two molecules in the same direction.
tRNAs move through the ribosomal sites in which order?
A, P, E
silent mutations
a nucleotide substitution that does not change the amino acid sequence (synonymous)
Misense mutation
changes the amino acid sequence
Nonsense mutation
can change an amino acid to stop a codon resulting in a shortened and unstable protein
hydrophilic
Attracted to water, polar
hydrophobic
not attracted to water, non polar
a molecule of water moving down its concentration gradient into a cell would require which type of transport?
passive transport through a channel or carrier protein
amphipathic
A molecule that has both a hydrophilic region and a hydrophobic region.
Central Dogma
DNA-transcription-RNA-translation-protein
which type of mutation repair occurs soon after DNA replication
mismatch repair
prokaryotes
No nucleus
Eukaryote
A cell that contains a nucleus and membrane-bound organelles
which type of RNA are involved in translation
mRNA, tRNA, rRNA
lipid bilayer
a structure formed of 2 layers of lipids in which the hydrophilic heads are the outside surfaces of bilayer, and hydrophobic tails are sandwiched in between, isolated from contact with aqueous environment
diffusion
Movement of molecules from an area of higher concentration to an area of lower concentration.
when a cell is placed in a certain solution, water flows out of the cell. what can be said about the solution surrounding the cell?
it has a higher concentration of solute than the inside the cell does
steps of cellular respiration
- glycolysis
- pyruvate oxidation
- the citric acid cycle
- oxidative phosphorylation
the citric acid cycle
Stage 2 of cellular respiration
Location: mitochondria matrix
What happens: The acetyl group of acetyl CoA is completely oxidized during the citric acid cycle
(T/F) If an enzyme inhibitor is similar in structure to an enzyme substrate it is likely to be a competitive inhibitor
true
Inhibitors
decrease the activity of enzymes
activators
increase the activity of enzymes
what is the direct energy source that drives the majority of ATP synthesis during cellular respiration
the proton-motive force across the inner mitochondria membrane
exergonic
spontaneous and release energy -ΔG
endergonic
non spontaneous and require energy +ΔG
NADH is an electron _______ because it is ________
donor, reduced
Oxidation
loss of electrons
reduction
gain of electrons
How is ATP generated in muscle cells
lactic acid fermentation, aerobic respiration, and B oxidation
Energy coupling always results in a net ________ ΔG which means the reaction is __________
negative, spontaneous
energetic coupling
a process in which a spontaneous reaction drives a non-spontaneous reaction
catabolism
the set of reactions that break down molecules and release energy
anabolism
the set of reactions that build molecules and require energy
what is oxidized in cellular respiration
C6H12O6+ O2 → Oxidized (glucose and oxygen)
what is the electron donor and final electron acceptor in photosynthesis?
water is the electron donor and NADP+ is the final electron acceptor
substrate-level phosphorylation
The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.
oxidative phosphorylation
The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.
2 Ways you can generate ATP during cellular respiration
- Substrate level phosphorylation
- Oxidative phosphorylation
2 Reactions of Photosynthesis
- Calvin cycle- in which carbon dioxide is reduced to form carbohydrates
- Light harvesting reaction- in which ATP and NAPH are generated to drive the Calvin cycle
Where does photosynthesis take place in eukaryotes?
Chloroplast
Where does the Calvin cycle occur?
stroma
the Calvin cycle
- addition of co2 (carboxylation)
- reduction
- regeneration
what form of energy is stored in the chemical bonds of glucose?
potential
Heat (thermal energy)
kinetic energy associated with the random movement of atoms or molecules
kinetic energy
energy of motion
potential energy
stored energy
chemical energy
A form of potential energy that is stored in chemical bonds between atoms.
NAD+ is the _______ form while NADH is the _______ form
oxidized, reduced
NO HYDROGEN =
OXIDIZED
IF THERE IS A HYDROGEN =
REDUCED
what 2 places can protein be produced and when are they sorted?
- free ribosomes in the cytosol = sorted after translation
- membrane bound ribosomes on the rough ER = sorted during translation
What is the difference in carbon sources between autotrophs and chemotrophs?
-autrophs obtain carbon from co2
-chemotrophs obtain carbon from organic carbon compounds (glucose
in which level of protein structure will hydrogen bonds between amino acid R groups form?
tertiary and quaternary
what do enzymes change about a reaction?
they decrease the activation energy, increase the rate of the reaction
which cytoskeletal polymers are polar?
microtubules and microfilaments
The process of converting the “message” of mRNA into a sequence of amino acids is called:
translation
In prokaryotes, what site on the mRNA does the ribosome bind to initiate translation?
shine-dalgarno sequence
in eukaryotes, what site on the mRNA does the ribosome bind to initiate translation?
first AUG
what are the 3 stop codons
(UAA, UAG, UGA)
The movement of molecules across a membrane from an area of higher concentration to an area of lower concentration is best described as
passive transport
primary structure
sequence of amino acids
The steps of signal transduction in order are
Activation, transduction, response, termination
long distance cell signaling
signals are produced by specialized cells and released into the bloodstream, which carries them to target cells in distant parts of the body
When cells send a signal, it is often in the form of a secreted molecule. In some cases, a cell will secrete a molecule that binds to a receptor on its own cell surface. What type of signaling is this?
Autocrine
t/f Paracrine signaling allows neighboring cells to communicate over relatively short distances
t
At which stage of meiosis is each chromosome composed of a single chromatid?
anapahse II
During which stage of meiosis does crossing-over occur?
prophase I
During which phase of the eukaryotic cell cycle does DNA and chromosome replication occur?
S phase of interphase
Secondary structure:
a-helices or b-sheets
Secondary protein structure: hydrogen bonding of the peptide backbone causes the amino acids to hold into a repeating pattern
Tertiary structure:
Tertiary protein structure: 3D folding pattern of a protein due to side chain interactions
how the secondary structure comes together in a 3D space
Quaternary Structure:
multiple polypeptides coming together
Quaternary protein structure: protein consisting of more than one amino acid chain
Properties of Water
Ice floats on water; , cohesion, adhesion, high surface tension, slow heat reactance, universal solvent.
Monomer + Energy
= Polymer
Amino acid (monomer) + energy
= Protein (polymer)
Enthalpy (ΔH):
total energy, chemical (potential) energy in bonds
Free energy (ΔG):
energy to do work
Entropy (ΔS):
disorder or unavailable energy
Less disorder (-ΔS),
more chemical energy in bonds (+ΔH)
More disorder (+ΔS),
ess chemical energy in bonds (-ΔH
Energetic coupling:
spontaneous reaction (-ΔG) drives a non spontaneous reaction (+ΔG
Irreversible inhibitor:
forms covalent bonds with enzymes & irreversibly activates them
reversible inhibitor:
: forms weak bonds with enzymes and can therefore easily dissociate from them
Feedback Inhibition
Product from end of pathway binds to and turns off enzyme at the start of the pathway through an allosteric inhibitor
Catalyzed reaction means that
an enzyme was used
Hydrophobic effect:
Non-polar molecules repelled by water.
Activation Energies:
Enzymes stabilize transition states, reduce activation energy
Steps of Translation:
Initiation, Elongation, Termination.
Prophase:
chromosomes condense
Prometaphase:
microtubules of the mitotic spindle attach to chromosomes
Metaphase
: chromosomes align in the center of the cell
Anaphase:
sister chromatids (which become individual chromosomes when the centromere splits) scepter and travel to opposite poles
Telophase:
Nuclear envelope reforms and chromosomes decondense.
Does passive transport require energy?
no
does active transport require energy
yes
