Carbohydrates and Their Composition
47 Questions
3 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the composition of sucrose?

  • Two α-D-glucose units
  • One α-D-glucose and one β-D-fructose (correct)
  • Two β-D-galactose units
  • One α-D-glucose and one β-D-galactose

Which disaccharide is known as milk sugar?

  • Trehalose
  • Maltose
  • Lactose (correct)
  • Sucrose

What are homopolysaccharides primarily composed of?

  • A mixture of monosaccharides and disaccharides
  • Different types of monosaccharides
  • Branched and multiple monosaccharide types
  • Only one type of monosaccharide (correct)

Which of the following polysaccharides is primarily used for energy storage in plants?

<p>Starch (A)</p> Signup and view all the answers

What type of glycosidic bond connects the monosaccharides in lactose?

<p>β (1 - 4) (D)</p> Signup and view all the answers

Which of these statements about polysaccharides is correct?

<p>They can consist of both linear and branched structures. (C)</p> Signup and view all the answers

What differentiates heteropolysaccharides from homopolysaccharides?

<p>Heteropolysaccharides are made from multiple types of monosaccharide units. (B)</p> Signup and view all the answers

Which of the following is NOT a characteristic of disaccharides?

<p>They are composed of three monosaccharide units. (D)</p> Signup and view all the answers

What is the configuration of the majority of naturally occurring monosaccharides in mammalian tissues?

<p>D-configuration (A)</p> Signup and view all the answers

Which type of mixture does not exhibit any optical activity?

<p>Racemic mixture (D)</p> Signup and view all the answers

What term is used for monosaccharides that differ in configuration around a single specific carbon atom?

<p>Epimers (A)</p> Signup and view all the answers

Which of the following sugars are classified as C4-epimers?

<p>Glucose and Galactose (C)</p> Signup and view all the answers

What is defined as the change in specific optical rotation during the interconversion of α and β forms of D-glucose?

<p>Mutarotation (D)</p> Signup and view all the answers

What is the term for stereoisomers that are mirror images of each other?

<p>Enantiomers (A)</p> Signup and view all the answers

Which carbon is referred to as the anomeric carbon in cyclic forms of D-glucose?

<p>C1 (A)</p> Signup and view all the answers

Which of the following statements is true regarding mutarotation?

<p>It results in an equilibrium mixture. (D)</p> Signup and view all the answers

What are the primary elements that compose carbohydrates?

<p>Carbon, hydrogen, and oxygen (D)</p> Signup and view all the answers

Which empirical formula typically represents carbohydrates?

<p>(CH2O)n (C)</p> Signup and view all the answers

What is the energy yield of carbohydrates upon oxidation?

<p>4 Cal/g (B)</p> Signup and view all the answers

What role do carbohydrates play in cellular structures?

<p>They participate in the structure of cell membranes. (D)</p> Signup and view all the answers

What is a characteristic of ketones?

<p>The carbon of the carbonyl group is bonded to two other carbons. (A)</p> Signup and view all the answers

Which of the following is a function of carbohydrates?

<p>They act as precursors for many organic compounds. (A)</p> Signup and view all the answers

Which carbohydrate serves as a storage form of energy in the body?

<p>Glycogen (C)</p> Signup and view all the answers

How can carbohydrates be defined chemically?

<p>As polyhydroxyaldehydes or ketones. (D)</p> Signup and view all the answers

What type of glycosidic linkages are present in amylose?

<p>α-1, 4 glycosidic linkages (B)</p> Signup and view all the answers

Which of the following accurately describes glycogen?

<p>It is similar to amylopectin but with more branches. (C)</p> Signup and view all the answers

What is the primary reason cellulose cannot be digested by mammals?

<p>Mammals lack the enzyme to cleave β-glycosidic bonds. (C)</p> Signup and view all the answers

Which of the following statements about inulin is false?

<p>It is utilized by the body for energy. (B)</p> Signup and view all the answers

Chitin is primarily found in which of the following?

<p>Invertebrate exoskeletons (B)</p> Signup and view all the answers

What type of carbohydrates are heteropolysaccharides composed of?

<p>Different types of sugars or their derivatives (C)</p> Signup and view all the answers

Which of the following correctly describes mucopolysaccharides?

<p>They are linear polymers of repeating disaccharide units. (A)</p> Signup and view all the answers

What makes amylopectin distinct from amylose?

<p>It has α-1, 6 glycosidic linkages at branching points. (D)</p> Signup and view all the answers

How are oligosaccharides classified?

<p>They have 2-10 monosaccharide units. (D)</p> Signup and view all the answers

What is the structural feature that leads to stereoisomerism in monosaccharides?

<p>The presence of asymmetric carbon atoms. (D)</p> Signup and view all the answers

Which statement is true regarding polysaccharides?

<p>They can be classified into two types: homopolysaccharides and heteropolysaccharides. (B)</p> Signup and view all the answers

What defines a D- or L-isomer in relation to monosaccharides?

<p>The orientation of the hydroxyl group on the penultimate carbon. (A)</p> Signup and view all the answers

What is the maximum number of isomers of glucose, given it has 4 asymmetric carbons?

<p>16 (A)</p> Signup and view all the answers

Which of the following does NOT belong to the classification of carbohydrates?

<p>Lactate (B)</p> Signup and view all the answers

What characterizes a homopolysaccharide?

<p>It is composed of only one type of monosaccharide. (C)</p> Signup and view all the answers

Which of the following is a characteristic of mucopolysaccharides?

<p>They are modified with carboxylate or sulphated groups. (C)</p> Signup and view all the answers

What is the primary component of agar?

<p>D-galactose and an L-galactose derivative (B)</p> Signup and view all the answers

What distinguishes glycoproteins from mucoproteins?

<p>Mucoproteins contain more than 4% carbohydrates. (A)</p> Signup and view all the answers

What role does lysozyme play concerning peptidoglycan?

<p>It hydrolyzes the β-1,4 glycosidic bonds between NAM and NAG. (D)</p> Signup and view all the answers

Which carbohydrate is mentioned as a component of glycoproteins?

<p>Mannose (B)</p> Signup and view all the answers

Which dietary fiber is primarily derived from apples and citrus fruits?

<p>Pectin (D)</p> Signup and view all the answers

What does the term 'mucoprotein' refer to in comparison with glycoprotein?

<p>It is used specifically for glycoproteins with high carbohydrate concentration. (C)</p> Signup and view all the answers

What provides mechanical strength to bacterial cell walls?

<p>Peptidoglycan (C)</p> Signup and view all the answers

Flashcards

Carbohydrates

Abundant organic molecules primarily composed of carbon, hydrogen, and oxygen.

Empirical formula of some carbohydrates

The formula (CH2O)n, implying a composition of carbon, hydrogen, and oxygen in a specific ratio.

Carbohydrates as source of energy

Primary dietary source of energy, providing 4 Calories per gram.

Carbohydrate Functions

Energy storage, structural components (e.g., cellulose), cell membrane constituents (glycoproteins/glycolipids).

Signup and view all the flashcards

Hydrates of Carbon

A historical term for carbohydrates, representing a general composition of carbon and water.

Signup and view all the flashcards

Carbonyl Group

Carbon double-bonded to oxygen (C=O).

Signup and view all the flashcards

Aldehyde

A carbonyl group connected to a hydrogen atom.

Signup and view all the flashcards

Ketone

A carbonyl group connected to two other carbon atoms.

Signup and view all the flashcards

Monosaccharides

The simplest carbohydrates, also known as simple sugars. They have the general formula Cn(H2O)n and cannot be further broken down into smaller units.

Signup and view all the flashcards

Oligosaccharides

Carbohydrates composed of 2 to 10 monosaccharide units linked together. They are produced when monosaccharides are joined by glycosidic bonds.

Signup and view all the flashcards

Polysaccharides

Large carbohydrates made up of long chains of monosaccharide units. They have high molecular weights and are often tasteless.

Signup and view all the flashcards

Homopolysaccharides

Polysaccharides made up of only one type of monosaccharide.

Signup and view all the flashcards

Heteropolysaccharides

Polysaccharides composed of different types of monosaccharides.

Signup and view all the flashcards

What determines a sugar's D or L isomer?

The spatial orientation of the hydroxyl (OH) group on the carbon atom adjacent to the terminal primary alcohol carbon. If the OH group is on the right side, the sugar is a D-isomer, and if it's on the left side, it's an L-isomer.

Signup and view all the flashcards

Stereoisomers

Molecules with the same structural formula but different spatial arrangements of atoms.

Signup and view all the flashcards

Asymmetric carbon

A carbon atom attached to four different atoms or groups. Its presence leads to stereoisomers in molecules.

Signup and view all the flashcards

D- and L-glucose

Two stereoisomers of glucose, mirroring each other, distinguished by the arrangement of the hydroxyl group on the chiral carbon furthest from the carbonyl group.

Signup and view all the flashcards

Optical Activity

The ability of a compound to rotate the plane of polarized light due to the presence of asymmetric carbon atoms.

Signup and view all the flashcards

Dextrorotatory (d+)

A compound that rotates the plane of polarized light to the right.

Signup and view all the flashcards

Levorotatory (l-)

A compound that rotates the plane of polarized light to the left.

Signup and view all the flashcards

Racemic Mixture

Equimolar mixture of d- and l-isomers, resulting in no optical activity.

Signup and view all the flashcards

Epimers

Monosaccharides that differ in configuration around a single specific carbon atom (other than anomeric)

Signup and view all the flashcards

Anomers

Cyclic forms of monosaccharides differing only in the configuration around the anomeric carbon (C1).

Signup and view all the flashcards

Mutarotation

The interconversion of α and β anomers of a sugar to an equilibrium mixture, resulting in a change in specific optical rotation.

Signup and view all the flashcards

Disaccharide

A carbohydrate composed of two monosaccharide units linked by a glycosidic bond. They are usually sweet and water-soluble.

Signup and view all the flashcards

Maltose

A disaccharide formed by two α-D-glucose units linked by an α(1→4) glycosidic bond.

Signup and view all the flashcards

Sucrose

A disaccharide composed of α-D-glucose and β-D-fructose linked by an α(1→β2) glycosidic bond. It is the most common table sugar.

Signup and view all the flashcards

Lactose

A disaccharide made up of β-D-galactose and β-D-glucose linked by a β(1→4) glycosidic bond. Found in milk.

Signup and view all the flashcards

α(1→4) Glycosidic Bond

A type of covalent bond that connects two monosaccharides in a disaccharide. In this specific bond, the α-anomer of the first sugar is linked to the 4th carbon of the second sugar.

Signup and view all the flashcards

Amylose Structure

Amylose is a straight chain polysaccharide composed of glucose units linked by α-1,4 glycosidic bonds. It is a primary component of starch, providing energy storage in plants.

Signup and view all the flashcards

Amylopectin Structure

Amylopectin is a branched chain polysaccharide composed of glucose units linked by α-1,4 glycosidic bonds in the linear chains and α-1,6 glycosidic bonds at the branching points. It's a major constituent of starch.

Signup and view all the flashcards

Glycogen Structure

Glycogen is a highly branched polysaccharide, similar to amylopectin but with more branches, serving as the primary form of glucose storage in animals.

Signup and view all the flashcards

Cellulose Structure

Cellulose is a straight chain polysaccharide composed of glucose units linked by β-1,4 glycosidic bonds, providing structural support to plant cell walls.

Signup and view all the flashcards

Why can't mammals digest cellulose?

Mammals lack the enzyme that can cleave β-1,4 glycosidic bonds present in cellulose. This enzyme is called cellulase, which is produced by some microorganisms in ruminants and herbivores.

Signup and view all the flashcards

Inulin Structure & Function

Inulin is a fructose polymer linked by β-1,2 glycosidic bonds with a terminal glucose. It is not utilized by the body and is used to measure kidney function.

Signup and view all the flashcards

Chitin Structure & Function

Chitin is a linear polysaccharide composed of N-acetyl glucosamine units linked by β-1,4 glycosidic bonds, providing structural support for the exoskeletons of invertebrates.

Signup and view all the flashcards

Glycoproteins

Proteins covalently bound to carbohydrates. The carbohydrate content can vary, and they are widely distributed in cells with diverse functions like enzymes, hormones, and receptors.

Signup and view all the flashcards

What are the key differences between mucopolysaccharides and glycoproteins?

Mucopolysaccharides are primarily carbohydrate chains with some modifications, while glycoproteins are primarily proteins with attached carbohydrate chains. The amount of carbohydrate in mucoproteins (a term used for glycoproteins with high carbohydrate content) can be significantly higher than in standard glycoproteins.

Signup and view all the flashcards

Agar

A complex sugar found in seaweed. It's made up of galactose and a modified galactose linked together. It's not digested and acts as dietary fiber.

Signup and view all the flashcards

Pectins

Found in fruits like apples and citrus. They are made of galactouronate and rhamnose. They are non-digestible fibers, used in jellies.

Signup and view all the flashcards

Peptidoglycan

A rigid component of bacterial cell walls. It's a complex carbohydrate with repeating units of N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG) linked together.

Signup and view all the flashcards

What is lysozyme's role in bacterial cell walls?

Lysozyme, an enzyme found in tears, targets the β-1, 4 glycosidic bonds between NAM and NAG in peptidoglycan, breaking down the bacterial cell wall.

Signup and view all the flashcards

N-acetylmuramic acid (NAM)

A modified form of N-acetylglucosamine (NAG). It has lactic acid attached to carbon three, making it unique.

Signup and view all the flashcards

More Like This

Carbohydrate Composition Quiz
5 questions

Carbohydrate Composition Quiz

ReachableHawk avatar
ReachableHawk
Carbohydrate Composition Quiz
5 questions

Carbohydrate Composition Quiz

UnquestionableHeliodor avatar
UnquestionableHeliodor
Carbohydrate Composition and Role Quiz
15 questions

Carbohydrate Composition and Role Quiz

AccomplishedBixbite avatar
AccomplishedBixbite
Carbohydrates and Their Tests
30 questions

Carbohydrates and Their Tests

DelightedObsidian8990 avatar
DelightedObsidian8990
Use Quizgecko on...
Browser
Open
Browser
Browser