Download Ch 6 Study Questions: An Introduction to Metabolism

READING GUIDE: CH 8 An Introduction to Metabolism
1) What is meant by “metabolism”?
● Totality of an organisms chemical
processes
2) Define the following terms. Give
an example of each.
● energy: the capacity to do work
● KE: Energy of movement;
Does work that alters state or
motion of matter (water
rushing through dam)
● PE: stored energy (water behind dam;
energy in the chemical bonds of food)
2) Define the following terms. Give
an example of each.
● chemical energy: a form of potential
energy (stored in chemical bonds of
molecules)
● entropy: a measure of disorder, or
randomness (the more disorder, the more
entropy)
3) Distinguish between catabolic and anabolic
pathways. Give an example of each.
● Catabolic pathways: release energy by
breaking down complex molecules to
simple (EX: cellular respiration)
● Anabolic pathpways: consume/use
energy to synthesize complex molecules
from simple (EX: photosynthesis or
protein synthesis)
4) What is meant by “free energy”?
● FREE ENERGY = portion of a system’s
energy available (“free”) to do work
(G)
5) When energy is converted, some becomes
unavailable to do work. What is the ultimate fate
of this unusable energy?
● Entropy (disorder); lost as heat
6) In the equation: ΔG = ΔH – TΔS, what does
each letter represent?
● ΔG: change in free energy
● ΔH: change in total energy (enthalpy)
● T: absolute temp (Kelvin)
● ΔS: change in entropy (disorder)
7) Using the equation in #6, how can we predict
whether or not a reaction will be spontaneous?
● If ΔG is negative, free energy is
released and the reaction will occur
spontaneously; If ΔG is positive, free
energy is consumed (NOT
spontaneous)
● *reactions tend to increase entropy (S)
(increase disorder)
8) Explain and give an example of the
following entropy changes:
● *INCREASE IN ENTROPY: products are
more disordered than the reactants
Example: breakdown/hydrolysis of
proteins  amino acids
● *DECREASE IN ENTROPY: products are
less disordered than reactants
Example: putting together thousands of
amino acids  protein
9) Contrast exergonic and endergonic reactions in terms
of: free energy, stability, and capacity to do work. Give
an example of each.
● Exergonic: release of free energy,
negative ΔG; energy made available to
do work (cellular respiration; hydrolysis
of a protein)
● Endergonic: absorbs / consumes free
energy, postive ΔG; stores free energy
(photosynthesis; formation of a protein)
10) Summarize the 1st and 2nd Laws
of Thermodynamics
● 1st Law: Energy is neither created nor
destroyed (total energy before and after
a chemical conversion is the same)
● 2nd Law: when energy is converted,
some becomes unavailable to do work;
every energy transfer increases the
entropy of the universe
11) Describe three kinds of work
done by a cell. (see sect. 8.3)
1. Mechanical: beating of cilia; moving
chromosomes
2. Transport: pumping of substances
across a cell membrane
3. Chemical: proteins synthesis,
DNA synthesis, anabolic reactions
12) Explain the concept of energy
coupling.
● Energy released from an exergonic
reaction is used to drive an endergonic
reaction (“downhill” process drives
“uphill” process)
**demo of this at the end!!! 
13) Define phosphorylated.
The hydrolysis of ATP releases an inorganic
phosphate group and energy; the
phosphate group is transferred to another
molecule, making it PHOSPHORYLATED.
(and more reactive)
**nearly all cellular work depends on this
process of transferring phosphate groups.
14) Draw and label ONE simplified diagram in which
you show an ATP, ADP, and AMP molecule. How
are they different?
● ATP = 3 phosphate groups
● ADP = 2 phosphate groups
● AMP = 1 phosphate group
15) Draw and label a simplified
diagram of the ATP cycle.
16) (caption of fig. 8.11): Energy released by
BREAKDOWN reactions (CATABOLISM) in
the cell is used to PHOSPHORYLATE ADP,
regenerating ATP. Chemical POTENTIAL
energy stored in ATP drive most CELLULAR
WORK.
Energy Coupling!
**a Rube-Goldberg machine…brought to
you by….
OK-GO!