Lesson 2 : Carbohydrates

Question 1

What are stereoisomers and how do they differ from structural isomers?

Answer 1

Stereoisomers have the same molecular formula & structure but differ in configuration or atom arrangement, unlike structural isomers.

Question 2

What do carbohydrates refer to in nutrition?

Answer 2

Carbohydrates refer to nutrients that provide energy for the body to enable it to perform work and maintenance of body processes.

Question 3

What are chiral centers in carbohydrates?

Answer 3

Chiral centers in carbohydrates are atoms with four different groups bonded to them, leading to non-superimposable mirror images.

Question 4

Why does the term ‘carbohydrate’ persist despite not being completely accurate?

Answer 4

The term ‘carbohydrate’ persists due to its firm root in chemical nomenclature, despite not entirely accurate.

Question 5

How are carbohydrates linked to dietary fibers?

Answer 5

Carbohydrates are linked to dietary fibers by providing sources of fiber in the diet.

Question 6

What is the difference between left-handedness and right-handedness in carbohydrates?

Answer 6

Left-handedness and right-handedness refer to different spatial arrangements of molecules in carbohydrates.

Question 7

Why are carbohydrates considered the most abundant organic compounds?

Answer 7

Carbohydrates are considered the most abundant organic compounds as they act as storehouses of energy, structural components in plants/animals, and essential components in nucleic acids.

Question 8

How are carbohydrates produced in plants?

Answer 8

Carbohydrates are produced by photosynthesis in plants.

Question 9

What are carbohydrates composed of?

Answer 9

Carbohydrates are composed of elements C, H, O.

Question 10

Give an example of a carbohydrate.

Answer 10

An example of a carbohydrate is Glucose with the formula C6H12O6 or C6(H2O)6.

Question 11

Why are carbohydrates important in preventing ketosis?

Answer 11

Carbohydrates are important in preventing ketosis by providing a source of energy that spares the breakdown of fats into ketones.

Question 12

What is the general formula for carbohydrates?

Answer 12

Carbohydrates have the formula Cn(H2O)m.

Question 13

How do carbohydrates supply carbon for synthesis of other substances?

Answer 13

Carbohydrates supply carbon for the synthesis of other substances by breaking down into carbon molecules that can be used for biosynthesis.

Question 14

What is the difference between structural isomerism and stereoisomerism?

Answer 14

Structural isomerism involves the same molecular formula but different bonding arrangements, while stereoisomerism involves the same molecular formula and structure but differ in configuration or atom arrangement.

Question 15

What are D & L Isomers in stereoisomerism?

Answer 15

D being dextrorotatory (clockwise, right) and L being levorotatory (counter-clockwise, left).

Question 16

How does optical activity relate to enantiomers?

Answer 16

Optical activity refers to the capacity of a substance to rotate plane-polarized light, which is a property of enantiomers.

Question 17

Define enantiomers in the context of stereoisomers.

Answer 17

Enantiomers are stereoisomers that are non-superimposable mirror images of each other.

Question 18

Define enantiomers in the context of stereoisomers.

Answer 18

Enantiomers are stereoisomers that are non-superimposable mirror images of each other.

Question 19

In what ways are carbohydrates linked to lipids and proteins?

Answer 19

Carbohydrates are linked to lipids and proteins structurally and functionally in the body.

Question 20

What are Fischer projections used for in carbohydrate chemistry?

Answer 20

Fischer projections are used to represent the spatial arrangement of molecules around chiral centers in carbohydrates.

Question 21

How do chiral centers contribute to the formation of stereoisomers?

Answer 21

Chiral centers allow the formation of stereoisomers due to their ability to exist in enantiomeric forms.

Question 22

How do carbohydrates spare the use of protein for energy?

Answer 22

Carbohydrates spare the use of protein for energy by providing an alternative source of energy in the form of glucose.

Question 23

What are some functions of carbohydrates in the body?

Answer 23

Functions of carbohydrates include providing energy, glycogen storage, carbon supply for synthesis, blood sugar regulation, fatty acid breakdown, dietary fibers, sparing protein for energy, linking to lipids and proteins, and providing flavor/sweeteners.

Question 24

What is optical isomerism and how is it related to carbohydrates?

Answer 24

Optical isomerism is the property of substances to rotate plane-polarized light, and in carbohydrates, it relates to their stereochemical configuration.

Question 25

What is glycogen and what is its role?

Answer 25

Glycogen is a carbohydrate that provides short-term energy reserves in the body.

Question 26

What did Emil Fischer contribute to the understanding of carbohydrate stereochemistry?

Answer 26

Emil Fischer made arbitrary assignments of D- and L- configurations to enantiomers of glyceraldehyde, contributing to carbohydrate stereochemistry.

Question 27

What is the role of carbohydrates in regulating blood sugar?

Answer 27

Carbohydrates play a role in regulating blood sugar levels in the body.

Question 28

How are bonds represented in Fischer projections?

Answer 28

How are bonds represented in Fischer projections?

Question 29

Give an example of a structural isomer of a carbohydrate.

Answer 29

Fructose is a structural isomer of glucose and galactose.

Question 30

Explain the concept of epimerism in stereoisomerism.

Answer 30

Epimerism in stereoisomerism describes stereoisomers that differ in the configuration around one chiral center.

Question 31

What are diastereomers and how do they differ from enantiomers?

Answer 31

Diastereomers are stereoisomers that are not mirror images of each other, unlike enantiomers.

Question 32

What are isomers in the context of carbohydrates?

Answer 32

Isomers are compounds with the same molecular formula but different structures.

Question 33

How are carbohydrates oxidized in living cells?

Answer 33

Carbohydrates are oxidized in living cells through respiration to produce CO2, H2O, and energy.