Tag: biomolecules

Questions Related to biomolecules

Which enzyme converts glucose to ethanol?

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. Diesterase

  2. Invertase

  3. Zymase

  4. Both (2) and (3)

Show answer
Correct Option: C
Explanation:

$Glucose\underrightarrow { Zymase } Ethanal$
Zymase converts glucose to ethanal

The light coming from the sun is stored as energy in plants by the process of photosynthesis. This happens by converting carbon dioxide and water into:

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. green leaves

  2. carbohydrates

  3. fats

  4. plants hormones

Show answer
Correct Option: B
Explanation:

Photosynthesis is the process by which plants utilize the energy from the sunlight in order to convert carbon dioxide and water into carbohydrates.

Formula of glucose is :

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. $C _{5}H _{12}O _{6}$

  2. $C _{6}H _{12}O _{16}$

  3. $C _{6}H _{12}O _{7}$

  4. $C _{6}H _{12}O _{6}$

Show answer
Correct Option: D
Explanation:

Formula of glucose is $C _6H _{12}O _6$ it is derived from the reaction of photosynthesis that is :


$6CO _2 + 6H _2O \overset{Sunlight}\longrightarrow C _6H _{12}O _6 + 6O _2$

Hence, the correct option is D.

Which of the following compounds will not undergo decomposition on passing electricity through aqueous solution?

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. Sugar

  2. Sodium chloride

  3. Sodium bromide

  4. Sodium acetate

Show answer
Correct Option: A
Explanation:

Sodium chloride, sodium bromide, and sodium acetate are all ionic compounds and hence, they dissociate into their respective ions in an aqueous solution. On the contrary, sugar is a covalent compound and hence does not dissociate into ions

The two functional groups present in a typical carbohydrate are :

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. $-CHO$ and $-COOH$

  2. $-CO$ and $-OH$

  3. $-OH$ and $-CHO$

  4. $-OH$ and $-COOH$

Show answer
Correct Option: B
Explanation:

Carbohydrates are polyhydroxy aldehydes or polyhydroxy ketones OR compounds which give aldehydic as well as ketonic groups on hydrolysis. Therefore the major functional groups are (carbonyl) Aldehyde, Ketone, and hydroxy groups. 

Out of $1$M glucose and $2$M glucose. 2M glucose has  a higher boiling point.

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

2 M glucose has a higher boiling point than 1 M of glucose.

Since on increasing the no of moles the molality also increases which is directly proportional to an elevation in boiling point.
Thus, the boiling point of the 2M of glucose will be greater than 1M glucose.

Which among the following is not the example of carbohydrate ?

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. Glucose 

  2. fractose

  3. Maltose

  4. Nylon

Show answer
Correct Option: D
Explanation:

$\rightarrow$ Carbohydrates are important source of instant energy in our body system.
$\rightarrow$ Honey has been used as instant source of enrgy in ayurvedic medicines.
$\rightarrow$ Carbohydrates are used as storage starch in plants and glycogen
$\rightarrow$ carbohydrates are also used in textile industry.

So, the correct answer is NYLON (It is a synthetic polymer)

For 'invert sugar', the correct statement(s) is (are)
(Given : specific rotations of (+) -sucrose, (+) -maltose, L-(-)-glucose and L-(+)-fructose in aqueous solution are $+66^0, +140^0, -52^0$ and $92^0$, respectively)

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. 'invert sugar' is prepared by acid catalyzed hydrolysis of maltose

  2. 'invert sugar' is an eqimolar mixture of D-(+)-glucose and D-(-)-fructose

  3. specific rotation of 'invert sugar' is $-20^0$

  4. on reaction with $Br _2$ water, 'invert sugar' forms saccharic acid as one of the products

Show answer
Correct Option: A
Explanation:

Invert sugar is a sucrose, partially or totally cleaved into fructose and glucose. Sucrose is converted into  invert sugar by chemical reaction called hydrolysis by heating a mixture or solution of table sugar.

Also, breakdown of sucrose may happen in a reaction catalyzed by enzymes such as sucrose, invertase etc or by acid catalyzed hydrolysis of maltose.

One mole of each of glucose and fructose require $x$ and $y$ moles of periodic acid respectively, for oxidation. Hence, $x/y$ is

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. $1/1$

  2. $2/1$

  3. $5/4$

  4. $9/4$

Show answer
Correct Option: A

Molisch test is answered by

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. All carbohydrates

  2. Sucrose

  3. Fructose
  4. Glucose
Show answer
Correct Option: A
Explanation:

Molisch test is a test for carbohydrate or compounds which can be dehydrated to furfural or furfural derivatives in the presence of the concentrated sulphuric acid .