Leader:
Exam 2 Review
Supplemental Instruction
Iowa State University
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A network of membranes that encloses the
nucleus, endoplasmic reticulum, Golgi
apparatus, lysosomes and vacuoles is the:
a) cytosol - fluids outside the organelles
“milk in the cereal”
b) endomembrane system
c) cytoplasm - cytosol + organelles within
them “milk and cereal”
d) extracellular matrix - all body fluid
outside the cell, not important to us atm
Enzymes lower activation energy by
a) changing local environment
b) straining bonds in reactants to make it
easier
c) position reactants together to facilitate
bonding
d) all of the above - close, strain, electron
rearrangement and covalent bonds
Listed below are structures or
characteristics of an enzyme, which would
make an enzyme less helpful:
a) activation site - where substrate must go
for reaction, great affinity for it and often
conformational changes
b) low Km -substrate concentration, lower
better don’t need to wait for a high
concentration
c) substrate - specific for each enzyme
d) allosteric - where inhibitors can bind
Secretion, processing, and protein sorting
happen where?
a) rough ER - protein synthesis and sorting
b) smooth ER - lipid synthesis and
modification, Ca balance, detoxification,
carb metabolism
c) Golgi Apparatus
d) cytoplasm
In the endomembrane system the nuclear
envelope is continuous with what other
organelle?
Supplemental Instruction
a) ER
b) golgi
c) membrane
Fluidity of a membrane is affected by all of
the following factors except:
a) fatty acid tail length - shorter = more
fluid
b) presence of cholesterols - support
c) highly permeable molecules - O2, N2 ect.
small uncharged polar molecues
d) double bonds in fatty acid tails - more
doubles more fluid
selective permeability - essential molecules
enter, metabolic intermediates remain,
waste products exit
An amino acid, water and O2 are trying to
get into Welch’s newest bar The Cell, but
the phospholipid bilayer of a bouncer wont
let them in! In order of most likely (highly
permeable) to least likely, who will get in?
O2>water> amino
In the question above, lets say that The Cell
was having a special and all solutes got in
free! Is The Cell violating the Hyper- or
Hypotonic fire code safety rule? What kind
of gradient would this be causing?
high concentration of solutes in = water
coming in, Hypo
high concentration out = water out, Hyper
Crenation - shrinking in hypertonic solution
transmembrane gradient -- Plasmolysis in
plants wilt
Turgor is pressure
Ion electrochemical gradient -both an
electrical
gradient and chemical gradient
Osmosis and Osmotic pressure (tendency to
move)
cute question, but our freshmen don’t go to
bars – right???
Semiautonomous organelles are:
a) completely independent of the cell they
are in
b) completely dependent of the cell they are
in
c) hold all the DNA of a cell - mitochondria
and chloroplast have their own DNA
while our DNA is in the nucleus
d) are only slightly dependent on the cell
they are in - need input, but can divide on
own
Cellular respiration is:
a) aerobic - needs O2
b) converts O2 -> CO2 - break down of
pyruvate and O2 used at the end of the
ETC to collect electrons and make H2O
c) aims to make NADH and ATP - every
step makes NADH or FADH2 to carry
electrons to ETC
d) living cells making energy from organic
molecules - glucose -> ATP
e) all of the above
Diagram the difference between anabolic
and catabolic reactions with ATP (Hint: its
a circular process so ATP comes from
what? and which needs energy and which
makes energy?)
substrate level phosphorylation - P to ADP
Chemiosmosis - energy in a gradient makes
ATP
Oxygen is reduced and Hydrogen is
oxidized:
a) O gains an electron H looses an electron
b) O looses an electron H gains an electron
NADH-->NAD+
a) NADH has been oxidized to NAD+ becomes more positive
b) NADH has been reduced to NAD+becomes more negative!
Which of the following does not carry the
molecules:
a) Facilitated diffusion - can carry, this just
means that a protein is helping the
diffusion
b) Uniporter - these two are classed by
movement and transporters often under
go ‘conformational change’ and are
called carriers, uni is one and goes one
direction
c) Antiporter, 2 or more in opposite
directions
d) Channels - can sometimes be gated but
not carriers
The primary difference between active and
passive transport - besides needing/not
needing energy - is? What is the primary
way active transport takes place?
H->L and L->H
pump then secondary is existing gradient
Draw a Na+/K+ - ATPase pump. Show the
direction of each element, the gradient that
it makes and what is driving the pump.
3 NA+ out 2 K+ in - more positive outside
chemical and electric gradient
Which of the following is not a step of
glycolysis:
a) energy investment - 2 ATP in to create
fructose 1,6 biphosphate
b) carbon fixation - in Calvin cycle
c) cleavage
d) energy liberation - get 2 pyruvate, 2
NADH and 4 ATP
Feedback inhibition occurs where in the
metabolic pathway of cellular respiration?
a) glycolysis - regulated by amount of ATP
in cell, non competitive, binds to an
allosteric point on phosphofructokinase
and prevents production of pyruvate
b) pyruvate break down
c) citric acid cycle - Oxaloacetate is a
competitive inhibitor of succinate
dehydrogenase
d) oxidative phosphorylation spelled wrong
throughout
e) no where
f) a & c
g) all of the above
a) substrate level
b) oxidative phosphorylation - no gradient!
A taunt bow or compressed spring is an
example of what kind of energy?
Potential
Which steps in the metabolic pathway of
cellular respiration occur in the cytosol?
a) glycolysis
b) pyruvate break down
c) citric acid cycle
d) oxidative phosphorylation
e) all but d
f) a & b
g) none of the above
What are the first two laws of
Thermodynamics?
1st law of conservation of energy
2nd increase in entropy every time energy is
transferred or transformed
Pyruvate dehydrogenase does all but:
a) make CO2
b) use H2O
c) attach an acetyl group
d) makes NADH
A reaction is said to be ‘ΔG>0’ therefore
the reaction is:
a) spontaneous
b) endergonic
c) exergonic
d) doesn’t require energy
everything else describing exergonic ΔG<0
ATP is only made in glycolysis and
oxidative phosphorylation.
a) true
b) false - 1 GTP->ATP per acetyl Co-a in
CC cycle
Draw a graph that shows the reactants and
products from the reaction described above:
products higher than reactants
Does this actually happen? how would you
get it to happen? coupling
What is activation energy and how does if
affect the rate of reactions?
energy needed to start reaction
higher, the harder, lower the easier
Glycolysis needs O2.
a) true
b) false
NAD+ -> NADH
a) NAD+ has been oxidized to NADH oxidized would make more positive
b) NAD+ has been reduced to NADHbecomes more negative!
In glycolysis how are the ATPs formed?
What isn’t formed in the Citric Acid Cycle?
a) NADH
b) FADH2
c) CO2
d) NADPH - plants
The Electron Transport Chain does:
a) gathers electrons from cell - thats what
NADH, FADH2 have been doing!
b) makes ATP - ATP synthase does that
c) makes an electron gradient - nope
d) makes a H+ gradient
The movement of electrons down the
Electron Transport Chain is a:
a) series of redox reactions
b) series of oxidative reactions - loosing
electrons
c) series of reductive reactions - gaining
electrons
Which is not a form of metabolic
regulation:
a) Gene regulation - turn on or off genes
b) Cellular regulation - cell signaling
pathways like hormones
c) Substrate regulation
d) Biochemical regulation - feedback
inhibition
Draw a graph of a noncompetitive and a
competitive inhibitor affecting a reaction
that shows the rate of the reaction vs. the
substrate concentration. Label Km and
Vmax.
Glycerols - glycolysis
Fatty acids - Acetyl Co-A
What are the 2 ways a cell can make ATP
under anaerobic conditions?
- Use substance other than O2
as final electron acceptor in
electron transport chain (ecoli uses NO3 -)
- Produce ATP only via substrate-level
phosphorylation
CO2 is produced in:
a) glycolysis
b) pyruvate break down
c) citric acid cycle
d) oxidative phosphorylation
e) all of the above
f) b & c
Vmax changed in non competitive
Km change in competitive
ATP is formed when:
a) ATP snythase moves counter clock wise
b) ATP snythase moves clock wise
The movement of electrons from NADH to
O2 by electron transport:
a) has negative free energy
b) drives protons across the mitochondrial
inner membrane creating a proton motive
force
c) results in ATP production by oxidative
phosphorylation
d) all of the above
e) none of the above
A pyruvate is turned into lactate:
a) when NADH needs to be regenerated
b) under anaerobic conditions - needs to
regenerate NAD+, has to put electrons
somewhere!
List where the following can be useful in
the metabolic pathway of cellular
respiration:
Amino acids - glycolysis, acetyl Co-A, CC
H2O is produced in:
a) glycolysis
b) pyruvate break down
c) citric acid cycle
d) oxidative phosphorylation
e) all of the above
f) b & c
Draw a chloroplast and label the following:
outer and inner membrane, thylakoid,
thylakoid lume, granum, stroma.
What happens in thylakoid? Stroma? Where
does CO2 enter and O2 exit? stomata Why
green? chlorophyll
In photosynthesis H2O is oxidized to CO2.
a) true
b) false -H2O oxidized, CO2 reduced
Draw an electron in its grounded state and
in its excited state:
The pigment that absorbs only Blue Green
(450-500 nm) light is:
a) Chlorophyll a - purple and red
b) Chlorophyll b - blue and little red
c) beta carotene
Where is O2 made in a chloroplast?
a) stroma - calvin cycle, ATP, NADPH
production
b) PSI - just helps NADP make NADPH
c) PSII - does the oxidizing of the water,
excited electrons travel to PSI
d) Thylakoid Lumen - this is where it
actually happens!
If a chloroplast just wanted to make ATP
how would it do this?
a) cyclic electron flow - PSI, brings in an
H+ back to PSI
b) noncyclic electron flow - linear, makes
NADPH and ATP
Which is not a step in the Calvin Cycle?
a) Carbon fixation - six CO2 -> RuBP, 6C > two 3C 3PG
b) Energy liberation - glycolysis
c) Reduction and Carbohydrate Production 12 ATP then reduced by 12 NADPH
make 12 G3P, 3 to carbs
d) Regeneration of RuBP- 10 G3P use
6ATP to go back to 6RuBP
carbs not actually made, G3P just a
precursor
A radish seed that is given only water but
not light, what will happen?
a) the seeds will develop normally
b) the seeds will preform light reactions and
germinate until the limiting the supply of
H2O runs out
c) the seeds will use ATP from
mitochondria and germinate but will not
be able to form light reactions
A C3 plant:
a) can add O2 to RuBP
b) release CO2
c) used when CO2 low and O2 high
d) 3PG
e) all of the above
A C4 plant makes oxaloacetate (4C
compound) in the 1st step of carbon
fixation. 4C releases steady supply of CO2
“hatch slack pathway” prevents
photorespiration and conserves water
The monomers of DNA are:
a) purines and pyrimidines AG and CT
b) nucleotides - phosphate, sugar, bp
c) chromosomes - condensed DNA
d) double helix - two strands twisted
DNA :
a) is double stranded - complementary and
antiparallel
b) has a sugar phosphate back bone covalent bonds
c) is stabilized by hydrogen bonding -2
between A-T and 3 between G-C <higher melting temp.
d) all of the above
Ratios of GTCA basepairs and the uniform
diameter of DNA is proof of what?
G-C and T-A
Starting with N15 you replicate Ecoli DNA
then you switch to N14. You get the
following results on the board:
drawing that would prove conservative