Download corrected true/false - CIA-Biology-2011-2012

Name: _________________
Date: _________________
KU
SBI4U UNIT TEST
Biochemistry
INQ
/23
COM
/12
APP
/6
/9
SCORE: __ + __ + __ + __= ___
A
B
C
D
50
PART A: Modified True/False (5 marks)
Indicate whether the sentence or statement is true or false. If false, change the identified word or
phrase (in italics) to make the sentence or statement true.
1.
_____ KU - Dipole forces occur between two molecules that are non-polar. _________________________
2.
_____ KU - Chitin is a type of fibrous protein. _______________________________
3.
_____ KU - A glycosyl linkage is found in a nucleic acid. _______________________________
4.
_____ APP – While you are sleeping at night, glycogen reserves are depleted. _____________________
5.
_____ KU - A radioisomer emits particles and/or energy in order to become a more stable. _______________
PART B: Multiple Choice (15 marks)
Identify the letter that best completes the statement or answers the question.
1. ______ KU - Which of the following is a trace element that is required by humans?
A)
B)
C)
D)
E)
Nitrogen
Calcium
Iron
Sodium
Phosphorous
2. ______ KU - Which of the following is considered to be the weakest type of bond?
A)
B)
C)
D)
E)
a non-polar covalent bond
a polar covalent bond
a London bond
a dipole bond
a hydrogen bond
3. ______ INQ - If you have 200 g of radioisotope with a half-life of 5 days, how much remains after 15 days?
A) 12.5 g
B)
C)
D)
E)
50.0 g
25.0 g
40.0 g
None will remain
4. ______ KU - Which of the following is a FALSE statement concerning amino groups?
A)
B)
C)
D)
E)
They are basic in pH.
They are proton acceptors.
They contain nitrogen.
They are non-polar.
They are components of the building blocks of proteins.
5. ______ KU - Humans can digest starch but not cellulose because:
A)
B)
C)
D)
E)
the monomer of starch is glucose, while the monomer of cellulose is galactose.
humans enzymes hydrolyze the alpha glycosidic linkage of starch but not the beta linkage of cellulose.
starch has a flip-flop arrangement of glucose, but cellulose does not
humans have symbiotic starch-digesting bacteria in the digestive tract.
starch is less complex a carbohydrate than cellulose.
6. ______ APP - Which of the following substances is NOT hydrophobic?
A)
B)
C)
D)
E)
Octane gasoline
Cholesterol
Lip balm
Ammonia
Methane
7. ______ KU - Why does ice float in liquid water?
A)
B)
C)
D)
E)
The liquid water molecules have more kinetic energy and thus support the ice.
The ionic bonds between the molecules in ice prevent the ice from sinking.
Ice always has air bubbles that keep it afloat.
Hydrogen bonds stabilize and keep molecules of ice farther apart than molecules of liquid.
The crystalline lattice of ice causes it to be denser than liquid.
8. ______ KU - Which of the following statements is (are) TRUE about the phosphate functional group?
A)
B)
C)
D)
E)
9.
It is found in RNA.
It has acidic properties.
It goes into ionized form in water.
All of the above statements are true.
Only A and B are true.
______ KU - Which statement about chemical bonds is NOT CORRECT?
A)
B)
C)
D)
E)
A covalent bond forms between the oxygen and hydrogen in hydroxyl.
A hydrogen bond forms between water and carboxyl groups.
A hydrophobic interaction binds complementary base pairs together in DNA.
A covalent bond forms between two cysteine amino acids.
An ionic bond binds positively charged and negatively charged R groups.
10. ______ KU - The hydrogenation of vegetable oil would result in which of the following?
A)
B)
C)
D)
E)
A decrease in the number of carbon-carbon double bonds in the fat molecule.
A decrease in the number of hydrogen atoms in the fat molecule.
The fat being solid at room temperature.
A and C only.
B and C only.
11. ______ INQ - Amylase promotes the hydrolysis of the polysaccharide amylose (starch) to monosaccharide
residues. To study the activity of amylase, a biologist prepares the following three flasks:
Support for the hypothesis of positive enzyme activity
can be obtained by comparing starch digestion in
A)
B)
C)
D)
E)
flasks A and B after 5 minutes.
flasks B and C after 5 minutes.
flasks A and C after 5 minutes.
flask A at time zero and again after 5 minutes.
flask B at time zero and again after 5 minutes
12. ______ APP - Which of the following sequences pairs could form a proper DNA double helix?
A)
B)
C)
D)
E)
5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5'
5'-A-G-C-T-3' with 5'-T-C-G-A-3'
5'-G-C-G-C-3' with 5'-T-A-T-A-3'
5'-A-T-G-C-3' with 5'-G-C-A-T-3'
A, B, and D are all correct.
13. ______ APP – Sickle cell anemia is a disease characterized by a single substitution of glutamine for valine in the
polypeptide. Which of the following is would be a correct prediction?
A)
B)
C)
D)
E)
The primary structure would be changed.
The tertiary structure would be changed.
The biological activity of this protein might be altered.
The number of amino acids present would stay the same.
All of the above are expected.
14. ______ KU – Which of the following is NOT TRUE of both starch and glycogen?
A)
B)
C)
D)
E)
They are both polymers of glucose.
Glycogen is found in animals while starch is found in plants.
The glucose of glycogen is not digestible, but the glucose in starch is.
They are both used for energy storage.
Glycogen is linear while starch is helical.
15. ______ INQ - An experiment was conducted whereby base was added in incremental volumes to acetic acid
(CH3COOH). Which statement is FALSE?
A) Prior to the addition of base, CH3COOH and its
conjugate base CH3COO- are present in the solution.
B) At the midpoint, pH is about 4.8.
C) The buffering range of acetic acid is between about
pH 4.2 and pH 6.2.
D) The buffering capacity is most effective at pH values
below 4 and above 6.
E) At the endpoint, all of the molecules of acetic acid
have been converted to the conjugate base, acetate.
PART C: Fill-in-the Blanks (15 marks)
Answer the following questions in the spaces provided.
1.
KU - Complete the following chemical reactions and identify the type of reaction shown. (6 marks)
a)
2.
glycine + __________  _____________ + dipeptide
Reaction Type: ________________
b) HCl + NaOH  ___________ + ____________
Reaction Type: ________________
c)
Reaction Type: ________________
_______ + H2O  1 glycerol + 3 ____________
INQ – Answer the following questions based on the set of molecules provided on the next page. (9 marks)
a)
What is the name of the chemical bond shown by the arrow in molecule J? ____________________
b) Which amino acid would be involved in disulphide bridge formation? State molecule letter. ________
c)
What is the name of the linkage seen in molecule D? ______________
d) Which two molecules represent structural isomers of each other? State molecule letters _____ & _____
e) Which amino acid has a hydrophobic R group? State molecule letter. _____
f)
What is the name of the linkage seen in molecule K? ______________
g)
What is the name of the linkage seen in A? _____________________
h) What is the name of the 3-carbon molecule that results when molecule D is hydrolyzed? ___________
i)
Could the R group seen in H act as an acid or a base? _____________
PART D: Short Answer (15 marks)
Answer the following questions in the spaces provided. Use point form if possible.
1.
KU - Complete the following chart. (4 marks)
Water
Property
Explanation
How does this property arise at the molecular level?
State one biological example
of this property.
Capillary action of water up
the xylem of a plant.
High Specific
Heat of
Vaporization
2.
COM - Illustrate the interaction between H2O
and CH3OH. Be sure to include the following
criteria. (3 marks)





3.
Correct molecular geometry.
Lone pairs, if present.
Partial charges, if present.
Overall polarity of molecules.
Intermolecular bonds, including type of
intermolecular bond.
APP - Explain what occurs at the molecular level when a raw egg is cooked into scrambled eggs. Explain your answer.
(2 marks)
4.
COM - Demonstrate the synthesis of
lactose sugar. Be sure to label all
reactants and products. Three simple
sugars are available at right for your
reference. (3 marks )
5.
APP – The diagram below shows a key
enzyme of photosynthesis involved in
producing glucose called Rubisco. As a
first step in this process, Rubisco binds to
molecule RuBP like a lock and key via
intermolecular attractions. A mutation has
occurred in Rubisco whereby lysine
(abbreviated as lys in the diagram) is
substituted with aspartic acid.
Predict how this mutation impacts the
of photosynthesis, and explain your
prediction. (3 marks)
a
rate