Biomolecules

Question 1

What is:

Biochemistry?

Answer 1

The study of chemical components within living systems/

Question 2

What are:

Cardohydrates?

Answer 2

Optically active polyhydroxy aldehydes or ketones or any substance that yeilds such units on hydrolysis.

sweet carbohyde

Question 3

Classify:

Carbohydrates based on their behaviour on hydrolysis:

Answer 3

• Monosaccharides
• Oligosaccharides
• Polysaccharides (non-sugars)

Question 4

List:

Examples of monosaccharides:

Answer 4

• Glucose
• Fructose
• Ribose

Question 5

List:

Examples of disaccharides:

Answer 5

• Sucrose (glucose + fructose)
• Maltose ( glucose+ glucose)

Question 6

List:

Examples of polysaccharides:

Answer 6

• Starch
• Cellulose
• Glycogen

Question 7

Classify:

Sugars on the basis of their reaction to Tollen’s and Felhing’s reagents:

Answer 7

• Reducing sugars ( all monosaccharides, lactose and maltose)
• Non-reducing sugars (sucrose)

Question 8

What is:

The configuration and opitcal activity of the glucose molecule?

Answer 8

D - ( + ) - glucose

Question 9

List:

Reactions with glucose:

Answer 9

• Reaction with HI
• Reaction with HCN and NH2-OH
• Reaction with Br water
• Reaction with acetic anhydride
• Reaction with conc. HNO3 (oxidation)

Question 10

List:

Reactions to justify the pyranose structure:

Answer 10

• no reaction with 2,4- DNP or Schiff’s test
• No addition product with NaHSO3
• Pentacetate does not react with NH2-OH
• 2 crystalline structures

Question 11

List:

The 2 types of glucose:

Answer 11

• Alpha glucose ( has H on top)
• Beta glucose ( has OH on top)

Question 12

What is:

The configuration and opitcal activity of the fructose molecule?

Answer 12

D - ( - ) - fructose

Question 13

List:

The 2 types of fructose:

Answer 13

• Alpha fructose ( has CH2OH on top)
• Beta fructose ( has CH2OH on the bottom)

Question 14

What is:

Sucrose?

Answer 14

A disaccharide ( C12H22O11) that is fromed by the glycosidic linkage between:
- a - D glucose and B- D fuctose ( C1 and C2)

(is a non-reducing sugar) (inversion of cane sugar)

Question 15

What is:

Maltose?

Answer 15

A disaccharide ( C12H22O11) that is fromed by the glycosidic linkage between:
- a - D- glucose and a- D glucose (C1 and C4)

(is a reducing sugar)

Question 16

What is:

Lactose?

Answer 16

A disaccharide ( C12H22O11) that is fromed by the glycosidic linkage between:
- B - D - galactose and B - D - glucose (C1 and C4)

(is a reducing sugar)

Question 17

List:

2 types of starch:

Answer 17

• Amylose ( polysaccharide of a - D - glucose ) with C1-C4 linkage. (water soluble) (15 - 20%)
• Amylopectin (polysacchairde of a - D- glucose + branching) with C1 - C4 linkage and branching at C1-C6 (water insoluble) (80 - 85%)

Question 18

What is:

Cellulose?

Answer 18

A polysaccharide of B - D - glucose (C1 - C4 linkage)

Question 19

What is:

A protein?

Answer 19

A polypeptide (a polymer of amino acids)

Question 20

Classify:

Proteins based on the proximity between the -NH2 and -COOH group:

Answer 20

• Alpha amino acids
• Beta amino acids
• Gamma amino acids

Question 21

Classify:

Amino acids on the basis of basicity/acidity:

Answer 21

• Neutral: (glycine, alanine and valine)
• Acidic (aspartic acid and glutamic acid)
• Basic (lysine)

Question 22

Classify:

Amino acids as essential/non-essential:

Answer 22

• Essential ( valine, leucine, arginine, threonine, lysine, isoleucine, methionine, valine, histidine, tryptophan, phenylalanine)
• Non- essential (everything else)

Question 23

What is:

A zwitterion?

Answer 23

a dipolar molecules that is amphoteric in a soltution.

Question 24

Classify:

Proteins as fiborous and globular:

Answer 24

• Fibrous (parallel polypeptide) (water insoluble) (keratin, myosin)
• Globular ( coiled polypeptide) (water soluble) (insulin, albumins)

Question 25

# List: Levels of protein structure:

Answer 25

- Primary - Secondary (a or b helix) - Tertiary (fibrous or globular) - Quaternary

Question 26

# What is: Denaturing of protein?

Answer 26

When a native protein is subjected to physical and chemical changes, it uncoils/unwinds and loses its biological activity. | ( The primary structure remains intact)

Question 27

# What is: A vitamin?

Answer 27

An organic compounds required in trace amounts through the diet in order to maintain optimum growth and health of organisms. ## Footnote (our bodies cannot produce most vitamins, except for the bacteria in the gut)

Question 28

# Classify: Vitamins are fat-soluble and water-soluble:

Answer 28

- Fat soluble (A, D, E, K) - Water soluble (B and C) | Except B12,none of the water soluble vitamins can be stored in the body.

Question 29

# Fill in: Deficiency of Vitamin A causes ---

Answer 29

--- Xerophthalmia and night blindness

Question 30

# Fill in: Deficiency of Vitamin B1 causes --- | B1 (thiamine)

Answer 30

Beri Beri

Question 31

# Fill in: Deficiency of Vitamin B2 causes --- | B2 (Riboflavin)

Answer 31

Cheilosis

Question 32

# Fill in: Deficiency of Vitamin B6 causes --- | B6 (pyridoxine)

Answer 32

Convulsions

Question 33

# Fill in: Deficiency of Vitamin B12 causes ---

Answer 33

Pernicious anaemia

Question 34

# Fill in: Deficiency of Vitamin C causes ---

Answer 34

Scurvy

Question 35

# Fill in: Deficiency of Vitamin D causes ---

Answer 35

Rickets in children and Osteo-malacia in adults

Question 36

# Fill in: Deficiency of Vitamin E causes ---

Answer 36

Fragility of RBCs and muscular weakness

Question 37

# Fill in: Deficiency of Vitamin K causes ---

Answer 37

Increased blood clotting time.

Question 38

# What is: A nucleic acid:

Answer 38

The particles in the cell nucleus responsible for heredity (chromosomes) are made of proteins and nucleic acids. A nucleic acid is a polymer of nucleotides..

Question 39

# What is: Products of hydrolysis of nucleic acids:

Answer 39

- Pentose sugar - Nitrogen base - Phosphoric acid group

Question 40

# Diff. between DNA and RNA

Answer 40

- DNA ( sugar = B - D- 2- deoxyribose) Base pairs = A, T, G, C Has a PO4 group - RNA (sugar = B- D - ribose) Base pairs = A, G, C, U Has a PO4 group

Question 41

# Diff. between: Nucleosides and Nucleotides:

Answer 41

- Nucleoside ( N.B at C1 ) - Nucleotide (N.B at C1 and PO4 at C5)

Question 42

# What is: A polynucleotide:

Answer 42

The C5 of a nucleotide is attached to the C3 of the other nucleotide (phosphodiester linkage) .

Question 43

# What is: Secondary structure of DNA:

Answer 43

(Watson and Crick helical model) A pairs with 2 H bonds to T G pairs with 3 H bonds to C

Question 44

# List: Types of RNA:

Answer 44

- mRNA - tRNA - rRNA

Question 45

# List: Types of Hormones:

Answer 45

- Steroid hormones (estrogen and androgen) - Polypeptide hormones (insulin and endorphins) - Amino acid derivative hormones ( epinephrine and norepinephrine)