Biology 1002 Midterm Questions With Complete Solutions
A-3 Finding in Lenskis experiment Correct Answers - During,
Lenski's experiment, at 30, 000 generations something occurred;
a novel phenotype appeared
- The flask line A-3 was growing better than the rest of the 11
flasks
- This was further studied because how could A-3 grow faster
when all of the cultures had the same amount of glucose
- There is another source in the culture which is called Fe-
citrate; the cells need iron and keeping it dissolved in the
solution you add citrate to the iron.
- It was thought to be, that for flask A-3, when glucose ran out,
there was a mutation in one of the A-3 cells that enables them to
use citrate as a growth source; allowing them to grow in the
aerobic condition (ecological opportunity)
- The mutation enabled A-3 to bring in citrate under aerobic
conditions and use the citrate as a carbon source, allowing it to
grow
Activator of Enzyme Function Correct Answers The
conformation of the active site is inaccessible to the substrate
until the activator binds somewhere else on the enzyme and
changes the conformation; the substrate can now bind. The
change in shape changes from a low affinity state to high
affinity
Addition of ADP and Pi in isolated mitochondria Correct
Answers Addition of ADP & Pi: Decrease in oxygen
concentration, declining even steeper. ATP and Pi increase
respiratory control (increases electron transport) ultimately
,making the process go faster which uses up and consumes more
oxygen.
Addition of an uncoupler in isolated mitochondria Correct
Answers Addition of Uncoupler: Decrease in oxygen
concentration, declining even more steeper. Adding an
uncoupler produces holes in the membrane so protons don't have
to wait to come into the ATP synthase; they can just flow back
into the membrane through the holes. The rate of electron
transport is the fastest in the presence of an uncolouper
(uncoupled rate) as long as substrates are there. Since electron
transport is at its fastest rate, it uses even more oxygen than
before
Addition of NADH in isolated mitochondria Correct Answers
Addition of NADH: Decrease in oxygen concentration. Adding
a substrate will kick in electron transport which uses and
consumes oxygen; decreases the amount of oxygen available
Ancestral culture in the experiment in bacteria Correct Answers
Ancestral: A culture of bacteria that remains untouched (like a
control group), you don't expose the culture to anything (change
in pH, temp, salt etc) and just see how it evolves as it normally
would.
Basic understanding of the Calvin cycle (1-5) Correct Answers
The Calvin cycle captures CO2 that comes from the atmosphere
and turns it into sugar (glucose)
Steps
1. C02 comes in from the atmosphere and is captured and enters
the calvin cycle
,2. Rubisco takes the CO2 molecule and binds it to a pre
assembled 5 carbon molecule, called RuBp
3. Now, with the addition of C02, it creates a 6 carbon molecule
4. The 6 carbon molecule rapidly splits in half into two shorter
chains (3 carbon molecule chain)
5. These 3 carbon chains are called PGA
Basic understanding of the Calvin cycle (6-10) Correct Answers
6. Entering the next part of the cycle, ATP delivers energy to the
molecule and NADPH binds one hydrogen molecule to each of
the PGA chains
7. Adding hydrogen to the PGA chains changes the molecule
into G3P
8. Glucose is formed by six carbon molecules that can be done
by the G3P molecule
9. There are by products along the way because RuBp needs to
be recreated by reusing material .. glucose takes 6 carbon but
RuBp needs 5 .. how does this work?
10. There is 5 other cycles happening at the same time, two of
the G3P molecules are syphoned off to produce the energy rich
6 carbon glucose chain and the rest of the 30 carbons are used to
recreated RuBp
Basics of a light responsive curve. Correct Answers - Light
intensity of 0 (in the dark): CO2 fixation is negative; no CO2 is
being consumed
- Light intensity of above 0-500: CO2 fixation increases as the
light intensity increases; the rate of photosynthesis goes up
because more CO2 is being consumed, increasing the rate of
photosynthesis
, - Light intensity above 600+: As the light intensity increases to a
high rate, CO2 begins to saturate and curves away; it will no
longer increase (It will plateau)
Basics of ATP hydrolysis and why its exergonic. Distinction
when an enzyme is involved. Correct Answers ATP hydrolysis:
The reaction that occurs when you add water
- ATP hydrolysis is exergonic because energy is released when
chemical bonds form (which that is what occurs in this reaction)
making there be less free energy in the products than there was
to begin with in the reactants
- When an enzyme is added to ATP hydrolysis, ATP hydrolysis
does not occur; H2O can not bind to the active site of an enzyme
Basics of cancer detection based on metabolism (using
radioactive forms of glucose) Correct Answers - Using
radioactive forms of glucose is another way of detecting cancer
- Glucose metabolism goes through the roof when cancer is
spreading
Basics of doing an "Ancestral vs Evolved" experiment in
bacteria Correct Answers - After 2000 generations, you can
equally mix the two cultures, place them on an agar plate under
low pH conditions and examine any growth changes (examine
on an agar plate of putting the solution directly on after mixing,
and examining an agar plate of waiting a day after the solution is
mixed, then putting it on the plate.
- Will the cells that were exposed to the low pH for 2000
generations be better adapted and grow faster after mixed with
A-3 Finding in Lenskis experiment Correct Answers - During,
Lenski's experiment, at 30, 000 generations something occurred;
a novel phenotype appeared
- The flask line A-3 was growing better than the rest of the 11
flasks
- This was further studied because how could A-3 grow faster
when all of the cultures had the same amount of glucose
- There is another source in the culture which is called Fe-
citrate; the cells need iron and keeping it dissolved in the
solution you add citrate to the iron.
- It was thought to be, that for flask A-3, when glucose ran out,
there was a mutation in one of the A-3 cells that enables them to
use citrate as a growth source; allowing them to grow in the
aerobic condition (ecological opportunity)
- The mutation enabled A-3 to bring in citrate under aerobic
conditions and use the citrate as a carbon source, allowing it to
grow
Activator of Enzyme Function Correct Answers The
conformation of the active site is inaccessible to the substrate
until the activator binds somewhere else on the enzyme and
changes the conformation; the substrate can now bind. The
change in shape changes from a low affinity state to high
affinity
Addition of ADP and Pi in isolated mitochondria Correct
Answers Addition of ADP & Pi: Decrease in oxygen
concentration, declining even steeper. ATP and Pi increase
respiratory control (increases electron transport) ultimately
,making the process go faster which uses up and consumes more
oxygen.
Addition of an uncoupler in isolated mitochondria Correct
Answers Addition of Uncoupler: Decrease in oxygen
concentration, declining even more steeper. Adding an
uncoupler produces holes in the membrane so protons don't have
to wait to come into the ATP synthase; they can just flow back
into the membrane through the holes. The rate of electron
transport is the fastest in the presence of an uncolouper
(uncoupled rate) as long as substrates are there. Since electron
transport is at its fastest rate, it uses even more oxygen than
before
Addition of NADH in isolated mitochondria Correct Answers
Addition of NADH: Decrease in oxygen concentration. Adding
a substrate will kick in electron transport which uses and
consumes oxygen; decreases the amount of oxygen available
Ancestral culture in the experiment in bacteria Correct Answers
Ancestral: A culture of bacteria that remains untouched (like a
control group), you don't expose the culture to anything (change
in pH, temp, salt etc) and just see how it evolves as it normally
would.
Basic understanding of the Calvin cycle (1-5) Correct Answers
The Calvin cycle captures CO2 that comes from the atmosphere
and turns it into sugar (glucose)
Steps
1. C02 comes in from the atmosphere and is captured and enters
the calvin cycle
,2. Rubisco takes the CO2 molecule and binds it to a pre
assembled 5 carbon molecule, called RuBp
3. Now, with the addition of C02, it creates a 6 carbon molecule
4. The 6 carbon molecule rapidly splits in half into two shorter
chains (3 carbon molecule chain)
5. These 3 carbon chains are called PGA
Basic understanding of the Calvin cycle (6-10) Correct Answers
6. Entering the next part of the cycle, ATP delivers energy to the
molecule and NADPH binds one hydrogen molecule to each of
the PGA chains
7. Adding hydrogen to the PGA chains changes the molecule
into G3P
8. Glucose is formed by six carbon molecules that can be done
by the G3P molecule
9. There are by products along the way because RuBp needs to
be recreated by reusing material .. glucose takes 6 carbon but
RuBp needs 5 .. how does this work?
10. There is 5 other cycles happening at the same time, two of
the G3P molecules are syphoned off to produce the energy rich
6 carbon glucose chain and the rest of the 30 carbons are used to
recreated RuBp
Basics of a light responsive curve. Correct Answers - Light
intensity of 0 (in the dark): CO2 fixation is negative; no CO2 is
being consumed
- Light intensity of above 0-500: CO2 fixation increases as the
light intensity increases; the rate of photosynthesis goes up
because more CO2 is being consumed, increasing the rate of
photosynthesis
, - Light intensity above 600+: As the light intensity increases to a
high rate, CO2 begins to saturate and curves away; it will no
longer increase (It will plateau)
Basics of ATP hydrolysis and why its exergonic. Distinction
when an enzyme is involved. Correct Answers ATP hydrolysis:
The reaction that occurs when you add water
- ATP hydrolysis is exergonic because energy is released when
chemical bonds form (which that is what occurs in this reaction)
making there be less free energy in the products than there was
to begin with in the reactants
- When an enzyme is added to ATP hydrolysis, ATP hydrolysis
does not occur; H2O can not bind to the active site of an enzyme
Basics of cancer detection based on metabolism (using
radioactive forms of glucose) Correct Answers - Using
radioactive forms of glucose is another way of detecting cancer
- Glucose metabolism goes through the roof when cancer is
spreading
Basics of doing an "Ancestral vs Evolved" experiment in
bacteria Correct Answers - After 2000 generations, you can
equally mix the two cultures, place them on an agar plate under
low pH conditions and examine any growth changes (examine
on an agar plate of putting the solution directly on after mixing,
and examining an agar plate of waiting a day after the solution is
mixed, then putting it on the plate.
- Will the cells that were exposed to the low pH for 2000
generations be better adapted and grow faster after mixed with
