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Exam 1 review
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Iowa State University
Tiffany
Biol 212 (1)
Powell-Coffman
01/30/2011
1. Define and rank from strongest (1)weakest (4)
2. Ionic bond= 2 atoms are so unequal in electronegativity that one atom steals an electron from
another atom (example NaCl)
1.Covalent bond= a bond where two electrons are shared between two atoms
Polar= unequal sharing of electrons
Non-polar=equal sharing of electrons
4.Van der Waals= weakest bond
3.Hydrogen bond= a hydrogen covalently bound to one electronegative atom is attracted to
another electronegative atom (such as N or O)
2.
covalent bonds
Hydrogen bonds
Label the two different bonds demonstrated in this diagram of water molecules. Which part of water is
more electronegative (label)? (Answer- the oxygen which is red-colored) Which bonds will break when
water vaporizes (label with an arrow)?
3. What do you expect would happen if these molecules were added to a solution of water? Why? Are
these molecules relatively polar or non-polar? Hydrophilic or hydrophobic?
They would most likely group together because they are non-polar and hydrophobic (water-fearing).
4. How will the molecule on the left affect a solution of water?
a.
b.
c.
d.
e.
It would make it more basic and raise pH
It would make it more acidic and lower pH
It would make it more basic and lower pH
It would make it more acidic and raise pH
Supplemental Instruction
1060 Hixson-Lied Student Success Center  294-6624  www.si.iastate.edu
Leader:
Course:
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Date:
Exam 1 review
Supplemental Instruction
Iowa State University
Tiffany
Biol 212 (1)
Powell-Coffman
01/30/2011
5. Will something basic lower or raise pH when added to solution? How about something acidic? Would a
basic or acidic solution have a higher concentration of H+?OH-?
Something basic would raise pH, something acidic would lower pH.
A basic solution will have a higher concentration of OH- and an acidic solution will have a
higher concentration of H+
6. Fill in the chart. For each of the pictured monomers, label the components.
Monomer
Polymer
Name of bond/linkage
connecting monomers
Nucleotide
DNA, RNA
Phosphodiester
linkage
monosaccharide
polysaccharide
Glycosidic linkages
Amino acid
Protein/peptide
Peptide bond
7. What do the following diagrams represent? What types of monomers are made into polymers by the
diagram on the left?
__________dehydration reaction____
_______hydrolysis____________
Monosaccharides, nucleotides, and amino acids are joined to form their respective polymers by
dehydration reactions.
8. For the following 4 amino acids, circle the carboxyl group, place a box around the R group, and place a
triangle around the amino group. Label each as Polar, non-polar, acidic, or basic and identify what about
the R group makes it that way.
____acidic, polar__
b/c of COOH group
______non-polar__
b/c of C-H bonds
___ ___polar____
b/c of O (high electroneg.)
__basic, polar___
dbl bound NH can accept an H+
Supplemental Instruction
1060 Hixson-Lied Student Success Center  294-6624  www.si.iastate.edu
Leader:
Course:
Instructor:
Date:
Exam 1 review
Supplemental Instruction
Iowa State University
Tiffany
Biol 212 (1)
Powell-Coffman
01/30/2011
9. Draw a phospholipid and label the hydrophobic and hydrophilic areas. How are phospholipids essential
to cell structure?
**Phospholipids make up the cell membrane!
Label the following levels of protein structure. What distinguishes each structure?
_______tertiary_____ ______quaternary___
____primary___
secondary ( alpha helix)
interactions between R groups complex of multiple proteins sequence of amino acids Hydrogen
bonding to form
alpha helix or beta sheet
10. Fill in the blanks
Cellular structure
Nucleus
Function(s)
Control center of cell, stores DNA
In eukaryotes?
Yes
In prokaryotes?
no
ER
Smooth-synthesizes lipids, steroids
Rough- proteins are synthesized
Translate mRNA into protein
Yes
No
Yes
Yes
Yes
No
Yes
No
Microtubules
Stores, modifies and sends out proteins
to other places in cell in vesicles
Destroys worn out organelles and old
cell material, is acidic
Moves things from place to place in cell
Yes
No
Actin
Enables cell movement
Yes
No
Plasma membrane
Semipermeable barrier of cell
Yes
Yes
Mitochondria
Where cellular respiration occurs
yes
No
Ribosomes
Golgi
Lysosome
Supplemental Instruction
1060 Hixson-Lied Student Success Center  294-6624  www.si.iastate.edu
Exam 1 review
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Tiffany
Biol 212 (1)
Powell-Coffman
01/30/2011
11. Illustrate and explain the difference between an allosteric and a competitive enzyme regulator
An allosteric regulator will bind to an enzyme at a place other than the active site and increase or
decrease the protein’s activity by this binding. A competitive inhibitor will bind to the active site of an
enzyme (where the substrate or reactant would usually bind) and prevent the substrate from being able
to bind and thus decrease the activity of the enzyme.
12. According to Professor Powell-Coffman, cell death will occur after 3-6minutes of hypoxia (no oxygen)
Why is this? Why is oxygen so important to us?(Hint: what is it’s role during cellular respiration)
During oxidative phosphorylation (third step of cellular respiration), oxygen is reduced in order to
generate ATP, which is used to power cellular work. In the absence of oxygen, the cell cannot produce
enough needed ATP to perform vital functions.
13. Describe what the electron transport chain and ATP synthase do. Where do these occur?
The electron transport chain establishes a proton (H+) gradient across the mitochondrial membrane
which has potential energy
The ATPsynthase uses the potential energy from the electron transport chain to generate ATP (which
will be later used to do cellular work!).
14. What is the chemiosmotic theory?
An electrochemical gradient has potential energy that can be harnessed to do work in a cell
15. What are some ways that a cell adapts to low oxygen levels?
Pyruvate levels increase, fermentation increases, and increased synthesis of glucose transporters (which
bring glucose into the cell)
16. What is the general formula for photosynthesis? for cellular respiration? Why can plants undergo
photosynthesis but animals can’t? How does photosynthesis sustain ecosystems?
Photosynthesis: 6CO2 + 6H2O 6O2 + C6H12O6
Cellular respiration: 6O2 + C6H12O6 6CO2 + 6H2O
Plants have chloroplasts (where photosynthesis occurs) but animals don’t. Photosynthesis sustains ecosystems by converting
solar energy to chemical energy and building complex organic molecules from CO 2
17. What is phosphofructokinase(PFK)? What are some inhibitors of PFK?
It is an enzyme that regulates step 3 of glycolysis
Citrate and ATP are inhibitors of PFK
Supplemental Instruction
1060 Hixson-Lied Student Success Center  294-6624  www.si.iastate.edu