Download Mid-Term Exam 1a - Buffalo State College Faculty and Staff Web

STATE UNIVERSITY COLLEGE AT BUFFALO
Department of Biology
Biology 100
Principles of Biology
Spring 2004
Dr. Wadsworth
Mid-Term Exam 1a
Biomolecules, Membranes and Cells
Cover Sheet
Name: ____________________________________________________
(Print)
Instructions.
1. Print your name in the space designated on this cover sheet.
2. Be sure that your exam has 9 pages including this cover sheet.
3. Read each question carefully and answer in the space provide
4. At the end of the exam there are 6 short answer questions. Answer only 5 of
these 6 questions. Answering all six questions may reduce your grade.
Under the question you choose not to answer, please write the word "Skip".
Failure to write "SKIP" under the one question you choose not to answer will
reduce your grade.
Multiple Choice
Choose the best answer for the question or the best ending for each statement. Write the letter
(A-E) which corresponds to the best answer on the line before the question. (2 pts each)
_____ 1. The functional group phosphate contains the atom phosphorus at its center. Based on
the structure of phosphate, what would be the valence # of phosphorus?
A.
B.
C.
D.
E.
1
2
3
4
5
_____ 2. Which of the subatomic components of an atom determine which element that atom is?
A.
B.
C.
D.
E.
Valence #
Electrons
Polar Bonds
Protons
Neutrons
_____3. Which of the following chemical bonds is the strongest?
A.
B.
C.
D.
E.
Hydrogen Bonds
Oxygen Bonds
Covalent Bonds
Hydrophobic Interactions
Intermolecular Interactions.
_____ 4. If an atom with a neutral electric charge has an atomic number of 45 and an atomic mass
of 90, then how many protons would it have?
A.
B.
C.
D.
E.
It would have no protons because it is neutrally charged.
It would have 90 protons.
It would have 180 protons .
It would have 45 protons.
It would be radioactive.
_____5. Only some hydrogen atoms are capable of forming hydrogen bonds. Which of the
following characteristics distinguishes those hydrogen atoms that can form hydrogen
bonds from those hydrogen atoms that cannot form hydrogen bonds?
A.
B.
C.
D.
E.
They are ions and have a negative charge which attracts other hydrogen atoms
They form covalent bonds with carbon atoms which makes them “sticky”
They attract other hydrogen atoms
They are covalently linked to other hydrogen atoms
They are participating in a polar covalent bond.
_____ 6. Carbon forms the backbone of all of the biomolecules within cells. Which of the
properties of carbon make it more suitable for forming these backbones when
compared to other atoms within cells such as oxygen and hydrogen?
A.
B.
C.
D.
E.
It has an atomic mass of 12
It can form 4 covalent bonds
It is an electronegative atom
It can form polar bonds with hydrogen
It easily loses electrons to form an ion
_____7. Which of the following functional groups is hydrophobic?
A. Carboxyl Group
B. Amino Group
C. Keto Group
D. Methyl Group
E. Phosphate Group
_____ 8. Polysaccharides are composed of which of the following subunits?
A.
B.
C.
D.
E.
Amino Acids
Fatty Acids
Alanines
Nucleic Acids
Sugars
____ 9. The oil found in olives represents a storage form of energy for the olive seed. What type
of biomolecule is olive oil?
A.
B.
C.
D.
E.
Triglyceride
Protein
Nucleic Acid
Phospholipid
Chitin
_____10. Proteins have which of the following functions?
A.
B.
C.
D.
E.
Structural
Hormones
Enzymes
Transport Molecules
All of the above
_____ 11. The cell walls that surround plant cells are composed of which of the following
biomolecules?
A.
B.
C.
D.
E.
Polysaccharides
Proteins
Nucleic Acids
Carbohydrates
Lipids
_____ 12. Which of the following best describes the “conserved” region of an amino acid?
A.
B.
C.
D.
E.
A long hydrocarbon chain saturated with hydrogens
A sulhydry group linked to a carboxyl group
A phosphate group linked to a carbon by a high energy bond.
A central carbon linked to a carboxyl and amino group
A carbon ring with an oxygen atom within the ring
_____ 13. Which of the following best describes the function of triglycerides?
A.
B.
C.
D.
E.
Structural component of cells
Storage form of energy
Backbone of biological membranes
A subunit making up cholesterol
A molecule made of 4 interlocking carbon rings
_____14. Which of the following is more hydrophobic?
A.
B.
C.
D.
E.
Amino Acids
Glucose
Starch
Polysaccharides
Triglycerides
_____ 15. In which of the following macromolecules would you expect to find a nitrogenous
base?
A.
B.
C.
D.
E.
Cellulose
Triglycerides
DNA
Lipids
Protein
_____ 16. Which of the following would you not find in a prokaryotic cell?
A.
B.
C.
D.
E.
Cytoplasm
Ribosome
Protein
Mitochondria
DNA
_____ 17. The endosymbiotic theory states that:
A.
B.
C.
D.
E.
Eukaryotes evolved from prokaryotes
Mitochondria arose from free living bacteria
Prokaryotes evolved from eukaryotes
Rough ER produces symbiotic proteins in the cell
Viruses reproduce by growing inside of human cells
_____ 18. Which of the following structures are found in both animal and plant cells?
A.
B.
C.
D.
E.
Chloroplast
Cell Wall
Central Vacuole
Stroma
Mitochondria
_____ 19. Which of the following best describes the function of the golgi in cells.
A.
B.
C.
D.
E.
It inserts proteins into fluid mosaic membranes.
It breaks downs sugars to provide the cell energy
It synthesizes the phospholipids component of membranes
It synthesizes all the proteins in the cell
It sorts membranes to different parts of the cell.
_____ 20. Which of the following is an example of a prokaryotic cell?
A.
B.
C.
D.
E.
Plant cell
Human cell
Fungal cell
Bacterial cell
Animal Cell
_____ 21. Unsaturated fatty acids cause membranes to remain fluid at low temperatures. What is
the chemical property of these phospholipids that promotes membrane fluidity?
A. The double bonds in the hydrocarbon chains causes kinks that prevent the chains
from packing tightly together
B. The loss of hydrogen associated with unsaturation makes the fatty acids “lighter” so
that they don’t congeal in the membrane.
C. Unsaturated fatty acids attract more cholesterol than saturated fatty acids.
D. Unsaturated fatty acids have long and straight hydrocarbon chains that do not get
knotted up so they can move around each other at the lower temperatures.
E. Unsaturated fatty acids bind to integral membrane proteins which promote membrane
fluidity.
_____ 22. Which of the following best describes the results of the activity of the
sodium/potassium pump?
A.
B.
C.
D.
E.
It converts chemical energy into electrical energy
It pumps glucose from the intestine into the circulatory system
It is responsible for osmosis in animal cells
It is the classic example of facilitated transport
It converts osmosis into simple diffusion
_____ 23. Which of the following is true about carrier proteins involved in facilitated transport?
A.
B.
C.
D.
E.
They extend across the bilayer membrane
They hydrolize ATP as an energy source
They reduce activation energy
They lack the specificity of enzymes
They are only found in animal cells
_____24. Biological membranes are called selectively premeable membranes because:
A.
B.
C.
D.
E.
They are composed of about 50% protein and 50% lipids
Charge molecules can not pass through the membrane
Active transport requires energy
Only some molecules pass through the membrane
Active transport requires a carrier protein
_____25. Which of the following is least likely to diffuse through a biological membrane?
A.
B.
C.
D.
E.
Oxygen
Carbon Dioxide
Sodium ions
Water
the small uncharged molecule methane
Short Answer Questions
Answer only five of the following six questions in the space below each question. Under
the one question you choose not to answer, write the word "SKIP".
26. The structure of the amino acid aspartate is drawn below. Explain why this molecule would
or would not be considered amphipathic.
27. Draw the structure of a monounsaturated fatty acid.
28. Draw the structure of a mitochondria and clearly label the two membranes and the spaces
separated by those membranes.
29. Describe the subatomic structure associated with a polar covalent bond.
30. Compare and contrast active transport with facilitated transport.
31. How does cholesterol affect the fluidity of biological membranes?