1
C1: Molecules of Life
nucleic acids
water
carbohydrates
31-Jul-17
Lipids
protein
2
water
31-Jul-17
3
Structure question
a) FIGURE 1 shows the water molecules.
A
B
FIGURE 1
(i) Name the bonds A and B.
Bond A: ________________
Bond B: ________________ [2 marks]
(ii) State THREE properties of water.
_____________________________________________________________________
_____________________________________________________________________
________________________________________________________________[3mks]
31-Jul-17
4
UPS (2009/10)
Structural question
(b) i. Draw and label the bond formed when two molecules of water are joined. [2m]
ii. State TWO properties of water.
_____________________________________________________________________
__________________________________________________________________ [2m]
iii. Why must water absorb relatively large quantity of heat in order to change its
temperature?
______________________________________________________________________
___________________________________________________________________ [1m]
5
Essay question
1. a) With a specific example, explain why water is known as a universal
solvent.
[8 marks]
b) Explain FOUR properties of water in living organisms.
31-Jul-17
[12 marks]
6
Carbohydrates
31-Jul-17
7
Carbohydrates
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8
UPS (2008/09)
Chapter 1: Molecules of Life
FIGURE 3.2
3b). FIGURE 3.2 represents a molecule of glucose.
(i) What type of glucose is represented in FIGURE 3.2?
_____________________________________
[1m]
(ii) Draw a disaccharide molecule formed from the above glucose molecules.
Name the disaccharide.
[3m]
c) Name a storage polysaccharide found in human body.
[1m]
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UPS (2006/07)
3.
Structural question
FIGURE 3 shows a chart to identify
five different types of carbohydrate.
(a) (i) Name the following molecules.
G : __________________
H : __________________
I : __________________ [3m]
(ii) List THREE common properties to all
monosaccharides and dissacharides.
FIGURE 3
______________________________________________________________________
______________________________________________________________________
__________________________________________________________________ [3m]
(iii) State TWO importance of glucose.
______________________________________________________________________
__________________________________________________________________ [2m]
(b
Give TWO significance of hydrogen bonding in water molecules.
______________________________________________________________________
__________________________________________________________________ [2m]
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UPS (2010/11)
Structural question
3. (a) Sucrose is formed from the condensation process of two monomers.
i. What are the monomers of sucrose?
_________________________________________________________________ [1m]
ii. Draw a structure of β-glucose.
[2m]
iii. State TWO functions of glucose.
____________________________________________________________________
__________________________________________________________________ [2m]
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PSPM 1 (2008/09)
Structural question
Figure 1 shows a structures of two types of polysaccharide. Polysaccharide A is a component of starch
and polysaccharide B is a component of plant cell wall.
(a) Name polysaccharides A and B.
A : __________________________________________
B : __________________________________________ [2m]
(b) State the specific names of the bonds labelled as P, Q and R.
P : __________________________________________
Q : __________________________________________
R : __________________________________________ [3m]
FIGURE 1
(c) Give ONE function of polysaccharide B. ________________________________________________ [1m]
(d) Why are human unable to digest polysaccharide B?
_________________________________________________________________________________ [1m]
(e) Hydrolysis of polysaccharide A produces disaccharide C. What is disaccharide C?
________________________________________________________________________________ [2m]
(f)
Why is polysaccharide A suitable as storage material?
________________________________________________________________________________
________________________________________________________________________________ [2m]
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13
UPS (2005/06)
Structural question
4.
FIGURE 2 shows the structural formula
of two organic molecules P & Q.
under electron microscope.
(a) Name the molecules P and Q.
i) Molecule P
: __________________
Molecule Q : __________________ [2m]
FIGURE 2
Molecules P and Q are combined to form a new
compound. Name the type of chemical reaction involved and its end product.
i) Type of chemical reaction
: ________________________________
ii) End product
: ________________________________ [2m]
iii) Show how molecules P and Q combined to form compound in b(ii). Circle the atom that
are removed during the formation of the compound as in b(ii). [4m]
(b)
(c)
(d)
Lipid and carbohydrates function as energy-storage molecules. Lipids stored more
energy per gram compared to carbohydrates. Why?
___________________________________________________________________
_______________________________________________________________ [1m]
State ONE other function of fats in living organisms.
___________________________________________________________________
________________________________________________________________ [1m]
14
UPS (2009/10)
3. (a) i. Draw and label the structure of a triglyceride molecule.
Structural question
[3m]
ii. How many molecules of water are lost in the formation of the triglyceride molecules?
__________________________________________________________________ [1m]
iii. Give ONE difference between phospholipids and triglycerides.
__________________________________________________________________ [1m]
15
UPS (2010/11)
Structural question
i. Name X and Y.
X
: ______________________________________
Y
: ______________________________________ [2m]
ii. Identify the main component of three molecules above.
_____________________________________________ [1m]
iii. Cold-blooded animals usually have higher proportion of
unsaturated fatty acids compared to warm-blooded animals.
Why?
_____________________________________________
_____________________________________________ [2m]
FIGURE 4
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Protein
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17
UPS (2007/08)
3.
(a)
Structural question
FIGURE 3 shows two levels of protein organization.
Determine the structure level of Y and Z proteins.
Y : __________________________
Z : _________________________ [2m]
(b) Name the type of bonds labelled V and W.
V : __________________________
W : _________________________ [2m]
FIGURE 2
c)
Haemoglobin is an example for Z, give TWO types of polypeptide chains that made up
this protein.
________________________________________________________________ [2m]
(d) Explain how heating may affect the tertiary structure of a protein.
________________________________________________________________ [2m]
(e)
Give ONE example of proteins based on the following functions:
[1m]
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UPS (2008/09)
Structural question
3. a) FIGURE 3.1 shows a polypeptide consisting of 15 amino acids.
FIGURE 3.1
(i) Name the bond between the amino acids in the polypeptide chains.
__________________________________________________________________ [1m]
(ii) What is group X?
__________________________________________________________________ [1m]
(iii) Which level of protein structure is shown by this polypeptide? Give a reason for your
answer.
_____________________________________________________________________
___________________________________________________________________ [2m]
(iv) Give an example of a protein that has the same structural level as the protein in FIGURE
3.1. ______________________________________________________________ [1m]
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PSPM 1 (2003/04)
Structural question
Figure 1 shows the structural formula of two organic monomers M and N.
Figure 1
(a) Identify the common name for organic materials M and N.
_________________________________________________________________________________ [1m]
(b) Identify the polymer that is produced from the bonding of monomer M and N.
________________________________________________________________________________ [1m]
(c) Identify the TWO functional groups found in monomers M and N and state the characteristic of each
functional group.
[4m]
Name of functional group
Characteristics
(d) Organic monomer M and N binds to form a new compound.
Name the type of chemical reaction and its product formed from this chemical reaction
(i) Name of chemical reaction
: ______________________________________
(ii) End product
: ______________________________________
[2m]
(e) In FIGURE 1, circle the atom that is expelled when the bond between organic monomers M and N formed.
[2//0]
PSPM 1 (2005/06)
Structural question
Figure 1 shows the structure of three amino acids.
(a) Name the groups labelled A, B and C.
A : ______________________________________
B : ______________________________________
C : __________________________________[3m]
(b) Show how valine and leucine combine to form
a dipeptide.
[3m]
Figure 1
(c) State TWO types of chemical bonds that maintain the configuration of globular protein.
___________________________________________________________________________________
_______________________________________________________________________________ [2m]
(d) State TWO factors that can change the configuration of globular protein.
___________________________________________________________________________________
___________________________________________________________________________________
_______________________________________________________________________________ [2m]
PSPM 1 (2006/07)
Structural question
Figure 1 shows a structural formula for a polypeptide molecule.
Figure 1
(a) State the name and the number of monomers that forms the polypeptide above.
(i) Name of monomer
: __________________________________________
(ii) Number of monomer
: __________________________________________ [2m]
(b) State the name of the bond formed in the synthesis of the polypeptide above. Draw arrows in FIGURE 1 to
show the bonds that you named.
_________________________________________________________________________________ [2m]
(c) State the name of the reaction involved in the following processes:
(i) adding one more monomer to the polypeptide above.
_____________________________________________________________________________
(ii) eliminating one monomer from the polypeptide above.
_____________________________________________________________________________ [2m]
(d) Compound A will be formed when a polypeptide is combined with nucleic acid. State compound a and the
cell structure that contains this compound.
Compound A : ______________________________________________________
Cell structure : ______________________________________________________ [2m]
(e) Polypeptide structure can be folded specifically to form an enzyme. State two types of bond which
maintain the configuration of an enzyme.
_________________________________________________________________________________
_________________________________________________________________________________[2m]
PSPM 1 (2007/08)
Structural question
FIGURE 2 shows two molecules of amino acids.
FIGURE 2
(a) Draw the structure as a result the combination of the two molecules.
(b) Name the chemical reaction involved and the type of bond formed during the
formation of dipeptide.
Chemical reaction
: ______________________________________________
Bond
: ______________________________________________ l2m]
(c) What is R in the above figure? ______________________________________________ [1m]
(d) Based on their functions, classify the proteins with their respective examples.
[4m]
[4 marks]
Class of protein
Example
(e) Why are some proteins known as conjugated proteins?
_________________________________________________________________________ [1m]
[2m]
PSPM 1 (2009/10)
Structural question
5 (a) Compare globular protein and fibrous proteins and give an example for each
(b) Differential between RNA and DNA
[10 marks]
[10 marks]
Nucleic acids
31-Jul-17
25
UPS2 (2006/07)
4.
(a)
FIGURE 4 shows a section of a DNA molecule.
Name P, Q and R.
P : __________________
Q : __________________
R : __________________ [3m]
(b)
What is the base sequence for 3’ 5’?
____________________________ [1m]
(c)
Structural question
FIGURE 2
Give TWO structural differences between a DNA molecule and a RNA molecule.
[1m]
(d) (i) The table below shows the percentage composition of bases in the DNA of cattle and
fish. Complete the table.
[1m]
(ii) Explain your answer in (d) (ii).
___________________________________________________________________
_________________________________________________________________ [2m]
26
PSPM 1 (2010/11)
Structural question
Figure 2 shows the structure of a
polynucleotide molecule.
(a) What are represented by P and S?
P : ______________________________
S : ______________________________ [2m]
(b) i. Name the polynucleotide molecule in FIGURE 2.
_________________________________________ [1m]
FIGURE 2
ii. State ONE types of polynucleotide molecules in (b) (i) and their functions.
Type of molecule : ___________________________________________________________________
Function
: ___________________________________________________________________
Type of molecule : ___________________________________________________________________
Function
: ___________________________________________________________________
(c) Name the bond E.
_______________________________________________ [1m]
[4m]
(d) Name the bond that binds S to the nitrogenous base.
________________________________________________ [1m]
(e) Name the type of nitrogen base represented by F.
________________________________________________ [1m]
27