chapter 1 : molecules of life (water)€¦ · relate the properties of water and its importance....

KMPk MOLECULES OF LIFE SB015

BIOLOGY TUTORIAL WORKSHEET

CHAPTER 1 : MOLECULES OF LIFE (WATER)

Subtopic : 1.1 Water

Learning Outcome :

i. State the structure and properties of water molecules

ii. Relate the properties of water and its importance.

PART A : MULTIPLE CHOICE QUESTIONS

1. Water is a universal solvent due to

its

A. Low viscosity

B. Polar molecules

C. High specific heat capacity

D. High boiling point

2. Water carries out all the following

functions in life, except as a

A. Lubricant

B. Cooling agent

C. Source of carbon

D. Chemical reagent.

3. Water has a high specific heat

capacity because

A. It can ionize

B. It is a poor insulator

C. Hydrogen bonds must be broken

to raise its temperature

D. Covalent bonds must be broken

to raise its temperature.

4. Leaves of plants pull water upwards

from the roots. Which property of

water explain this

A. Solubility

B. Polarity

C. Low viscosity

D. Cohesion and adhesion forces.

5. Which of the following is possible

due to the high surface tension of

water?

A. Water can acts as a solvent

B. Ice is formed at low temperature

C. A water strider can walk on

water

D. Lakes do not freeze solid during

winter.

6. What properties of water that help it

to moderate changes in temperature?

A. Cohesion and adhesion

B. Polarity and hydrogen bonding

C. Solvent and high specific heat

capacity

D. High specific heat capacity and

high heat of vaporization

7. Properties of water include

I. High surface tension

II. High specific heat capacity

III. Expanding when frozen

A. I only

B. I and II only

C. II and III only

D. I, II and III

KMPk MOLECULES OF LIFE SB015 PART B : STRUCTURED QUESTIONS

1. Label the angle between the covalent bonds of water molecule (C1)

2. Describe the properties of water and its importance (C2)

•••

Universal solvent due to its polarity

•••

Low viscosity

•••

High specific heat capacity

•••

High latent heat of vaporization

•••

High surface tension

•••

Maximum density at 4°C


3. a) Draw water molecules and label the

i. angle within water molecule

ii. hydrogen bond

[3 marks]

b) State FIVE properties of water [5 marks]

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c) Give TWO significance of hydrogen bonding in water molecules. [2 marks]

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d) Which property of water helps organisms regulate their body temperature more

effectively? [ 1mark]

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e) Why must water absorb relatively large quantity of heat in order to change its

temperature? [2 marks]

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f) Why water is a polar molecule? [2 marks]

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4. FIGURE 1 shows the interaction between water molecules.

FIGURE 1

(i) Name the bonds labeled A and B in FIGURE 1. [2 marks]

Bond A : ______________________________________________________________

Bond B : ______________________________________________________________

(ii) How many water molecules can bind with one water molecule? [1 mark]

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(iii) Which property of water gives cooling effect to organisms? [1 mark]

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(iv) Why water is a good solvent? [2 marks]

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PART C : ESSAY QUESTION

1. Explain FIVE properties of water in living organisms. (C2) [10 marks]

A

B


CHAPTER 1 : MOLECULES OF LIFE (CARBOHYDRATE) Subtopic : 1.2 Carbohydrates

Learning Outcome :

i. State the classes of carbohydrates

ii. Illustrate the formation and breakdown of maltose

iii. Compare the structures and functions of starch, glycogen and

cellulose.


1. All of the followings are

characteristics of monosaccharides

except

A. Sweet tasting

B. Dissolve in water

C. Insoluble in water

D. Form white crystal

2. Most carbohydrate in plants are

transported in the form of

A. Glucose

B. Sucrose

C. Maltose

D. Lactose

3. The linear amylose chain coils into a

helix held by

A. Hydrogen bonds

B. Glycosidic bonds

C. Peptide bonds

D. Disulphide bonds

4. Which of the following is made up

of the condensation of β-glucose

monomers?

A. Sucrose

B. Cellulose

C. Starch

D. Glycogen

5. Choose the incorrect match of the

carbohydrate and its function

A. Sugar transport in plants –

disaccharide

B. Energy storage in animals-

disaccharide

C. Energy storage in plants-

polysaccharide

D. Energy source in human-

monosaccharide

6. Which of the following statements

about carbohydrate is NOT true?

A. Monosaccharide also known as

simple sugar

B. Monosaccharide can be joined

together with peptide bonds

C. Cellulose and lactose are

carbohydrates

D. Glycogen is a storage

carbohydrate in animal cells.

7. The important roles of carbohydrate

include as a

I. Buffer

II. Structural component

III. Food storage compound

A. I only

B. I and II only

C. II and III only

D. I, II and III


1. State three classes of carbohydrates with examples and their functions.

2. Name the groups of monosaccharides shown in FIGURE 2.

FIGURE 2 : Linear structure of monosaccharide

3. Name the structure shown in FIGURE 3.

FIGURE 3


4. Identify and name the process involves in the formation and breakdown of maltose in

FIGURE 4.

FIGURE 4

5. Name the structure shown in FIGURE 5.

FIGURE 5

6. FIGURE 6 shows the structural formula of a disaccharide.

FIGURE 6


a) Name the disaccharide shown in FIGURE 6. [1 mark]

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b) What is the monomer of the disaccharide shown above? [1 mark]

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c) Name the bond that links the two monomers. [1 mark]

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d) List TWO characteristics of polysaccharide. [2 marks]

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PART C : ESSAY QUESTIONS

1. List FOUR main functions of carbohydrates and give an example of each.(C1) [8 m]

2. Give an example of disaccharides and polysaccharides. Compare disaccharides and

polysaccharides.(C2) [8 m]

3. Differentiate between starch and cellulose. (C2) [6 m]


CHAPTER 1 : MOLECULES OF LIFE (LIPIDS)

Subtopic : 1.3 Lipids

Learning Outcome :

i. State the types of lipid: triglycerides (fats and oil), phospholipids and steroids.

ii. Describe the structure of fatty acids and glycerols.

iii. Explain the formation and breakdown of triglycerides.

PART A : MULTIPLE CHOICE QUESTIONS.

1. The phosphate group in phospholipids

is

A. Polar and hydrophilic

B. Non-polar and hydrophobic

C. Ionized in water

D. Uncharged

2. A fatty acid is saturated if its

hydrocarbon chain

A. Is shorter with one double bond

B. Has one or more double bonds

C. Contain the maximum number of

oxygen atoms

D. Contain the maximum number of

hydrogens atoms.

3. How many of fatty acids molecules are

present in a triglyceride molecule?

A.2

B.1

C.4

D.3

4. Triglycerides are formed from the

condensation of

A. Three molecules of glycerol and

one molecule of fatty acid

B. Three molecules of fatty acid and

one molecule of glycerol

C. Three molecules of fatty acid and

three molecules of glycerol

D. One molecule of fatty acid and

one molecule of glycerol.

5. Which of the following statements

does not describe the function of

lipids?

A. An electrical insulator

B. A thermal insulator

C. A source rich in energy

D. Form cell walls.

6. Which of the following molecules is

not grouped with lipids

A. Testosterone

B. Lecithin

C. Cholesterol

D. Insulin

7. Lipids that are commonly found in

plants and animals include

I. Collagens

II. Steroids

III. Triglycerides

A. I only

B. I and II only

C. II and III only

D. I, II and III

8. The major difference between a

structural lipid, such as those in cell

membrane, and a storage fat is the

fact that the structural lipid: A. Most commonly contain

phosphate group B. Does not contain glycerol C. Has four fatty acids attached to

the glucose D. Is entirely hydrophobic and non

polar.


PART B : STRUCTURED QUESTIONS

1. State three types of lipid with examples and its characteristics.

2. Label FIGURE 7.

FIGURE 7 :The structure of triglyceride


3. Label the molecules and process involved in FIGURE 8.

FIGURE 8

4. FIGURE 9 shows the structure of a triglyceride molecule or fat.

FIGURE 9

a) Name the type of fat in FIGURE 9. [1 mark]

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b) Give the reason for your answer in 4 (a). [1 mark]

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c) Name the type of reaction that breaks the compound in FIGURE 9. [1 mark]

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PART C : ESSAY QUESTION 1. Using a suitable labeled diagram, describe the formation and breakdown of triglyceride

[10 marks]


CHAPTER 1 : MOLECULES OF LIFE (PROTEINS)

Subtopic : 1.4 Proteins

Learning Outcome :

i. Describe the basic structure of amino acids.

ii. State how amino acids are grouped

iii. Describe primary, secondary, tertiary and quaternary levels of proteins and the types

of bonds involved.

iv. Describe the effect of pH and temperature on the structure of protein.

v. Describe the formation and breakdown of dipeptide.

vi. Classify proteins according to their structure and composition.


1. Which bonds are created during the

formation of the primary structure of a

protein?

A. Peptide bonds

B. Hydrogen bonds

C. Disulfide bonds

D. Phosphodiester bonds

2. The structural level of a protein most

affected by disruptions in hydrogen

bonding is the

A. primary level

B. secondary level

C. tertiary level

D. quaternary level

3. Which of the following is not a

protein?

A. Haemoglobin

B. Glycogen

C. Antibody

D. Insulin

4. A strong covalent bond between amino

acids that functions in maintaining a

polypeptide’s specific three dimensional

structure is a (an)

A. Ionic bond

B. Hydrophobic interaction

C. van der Waals interaction

D. Disulfide bond

5. Polysaccharides, proteins and nucleic

acids are similar in that they

A. Synthesized from monomers by the

process of hydrolysis

B. Synthesized from monomers by

dehydration reactions

C. Synthesized as a result of a peptide

bond formation between monomers

D. Decomposed into their subunits by

dehydration reaction.


PART B : STRUCTURED QUESTION

1. Label the basic structure of amino acids.

FIGURE 10 : Amino acid monomer

2. Levels of protein

3. Effect of pH and temperature on the structure of protein


4. Name the process involved in the formation and breakdown of dipeptide.

FIGURE 11: Formation of dipeptide

FIGURE 12 : Breakdown of dipeptide

5. Label the types of bonds involved in different structural level of protein.


FIGURE 13 : Levels of protein structures

6. Name the bonds involved in tertiary level of protein.

FIGURE 14 : Tertiary structure

7. Classify proteins according to their structures.

FIGURE 15 : Classification of protein structure


8. Sketch graph for each factor affecting protein structure. Label the axis.

9. Label denaturation and renaturation of a protein.

FIGURE16

10. FIGURE 17 shows the organization level of protein structure.

A B C D

FIGURE 17


(a) What is the organization level of protein structure shown by C and D in

FIGURE 17 ? [2 marks]

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(b) List TWO types of bonds involved in maintaining the protein structure in 10 (a).

[2marks]

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(c) State TWO structural differences between protein C and D [2 marks]

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(d) Based on their functions, classify the proteins with their respective examples. [4 marks]

Class of Protein Example

PART C : ESSAY QUESTIONS

1. Explain FOUR structural levels of proteins. (C2) [14 marks]

2. Explain the effects of pH and temperature on the structure of protein.(C2) [6 marks]


CHAPTER 1 : MOLECULES OF LIFE (DNA and RNA molecules )

SUBTOPIC : 1.5 : DNA and RNA molecules

LEARNING OUTCOME:

✔ State the structure of nucleotide as the basic components of nucleic acid (DNA

and RNA).

✔ Illustrate the structure of DNA based on the Watson and Crick Model.

✔ State the types of RNA.

✔ Compare DNA and RNA.

PART A MULTIPLE CHOICE QUESTIONS

1. Ribose and deoxyribose are

A. Nucleotides

B. Disaccharides

C. Pentose sugars

D. Nitrogenous bases

2. The phosphodiester linkage in DNA

or RNA is formed between

A. Two bases

B. Two phosphates

C. Sugar and base

D. Sugar and phosphate

3. The double helix structure of DNA is

held together by

A. Ionic bonds

B. Peptide bonds

C. Hydrogen bonds

D. Phosphodiester bonds

4. Choose the correct statement

A. the molecular structure of a purine

base is a double ring

B. the molecular structure of a

pyrimidine base is a double ring

C. adenine and thymine are purine

bases

D. cytosine and guanine are

pyrimidine bases.

5. The double helix structure of DNA is

maintained by the bond formed

between

A. a sugar and a phosphate group

B. a sugar and a nitrogenous bases

C. a purine base and a pyrimidine

base

D. the same groups of nitrogenous

base


1. Name the components of a nucleotide.

2. Label the structure of DNA based on the Watson and Crick Model.


3. FIGURE 18 shows a monomer of a DNA molecule.

FIGURE 18

(a) Name the monomer. [1 marks] _____________________________________________________________________

(b) Based on FIGURE 18 label A and B. [2 marks]

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(c) Guanine and cytosine are the organic bases in the formation of DNA molecule.

Name the bond that binds the two bases. [1 mark]

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(d) How many bonds are formed between the bases in 3 (c)? [1 mark]

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(e) Give TWO differences between DNA and RNA based on component B and C. [2 marks]

DNA RNA

PART C : ESSAY QUESTION

1. Differentiate DNA and RNA based on their structure. [ 10 marks]

C

B

A

chapter 1 : molecules of life (water)€¦ · relate the properties of water and its importance....

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