Carbohydrates and Their Functions Quiz
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Questions and Answers

Which of the following compounds is NOT classified as a carbohydrate?

  • Sucrose
  • Acetic Acid (correct)
  • Starch
  • Glucose

All compounds fitting the formula Cx(H2O)y are classified as carbohydrates.

False (B)

Name one sweet carbohydrate commonly used in homes.

Sucrose

Carbohydrates primarily produced by __________ are a large group of naturally occurring organic compounds.

<p>plants</p> Signup and view all the answers

Match the following carbohydrates with their description:

<p>Glucose = A simple sugar used in energy production Starch = A storage form of glucose in plants Lactose = Sugar found in milk Sucrose = Common household sugar</p> Signup and view all the answers

Which of the following biomolecules plays a role in the functions of organisms alongside carbohydrates?

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

Rhamnose is a compound that fits the carbohydrate definition based on its molecular formula.

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

What is the general formula for carbohydrates?

<p>Cx(H2O)y</p> Signup and view all the answers

Which of the following is a monosaccharide?

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

All polysaccharides are sweet in taste.

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

What are oligosaccharides composed of?

<p>Two to ten monosaccharide units</p> Signup and view all the answers

Glucose is classified as an ___________ because it contains an aldehyde group.

<p>aldose</p> Signup and view all the answers

Match the following types of carbohydrates with their definitions:

<p>Monosaccharides = Single sugar units Oligosaccharides = Two to ten sugar units Polysaccharides = Large sugar units Disaccharides = Two sugar units</p> Signup and view all the answers

Which reaction is used to prepare glucose from sucrose?

<p>Boiling with dilute HCl (D)</p> Signup and view all the answers

All monosaccharides are reducing sugars.

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

What is the molecular formula of glucose?

<p>C6H12O6</p> Signup and view all the answers

Sucrose is composed of glucose and ___________.

<p>fructose</p> Signup and view all the answers

Match the following carbohydrates with their types:

<p>Starch = Polysaccharide Maltose = Disaccharide Galactose = Monosaccharide Cellulose = Polysaccharide</p> Signup and view all the answers

Which type of sugar results from the hydrolysis of starch?

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

Glucose and fructose are isomers of each other.

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

What does the 'D' in D(+)-glucose represent?

<p>The configuration relative to glyceraldehyde</p> Signup and view all the answers

Polysaccharides yield a __________ number of monosaccharides on hydrolysis.

<p>large</p> Signup and view all the answers

Which functional group characterizes ketoses?

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

What component of starch is responsible for its water solubility?

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

Glucose is a non-reducing sugar.

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

What type of linkage connects the glucose units in cellulose?

<p>C1-C4 glycosidic linkage</p> Signup and view all the answers

Glycogen is primarily stored in the ______ of animals.

<p>liver</p> Signup and view all the answers

Match the polysaccharides with their primary function:

<p>Starch = Storage in plants Glycogen = Storage in animals Cellulose = Structural component in plants Chitin = Structural component in fungi</p> Signup and view all the answers

Which of the following is NOT a component of starch?

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

All amino acids are essential for the body and must be obtained from diet.

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

What distinguishes essential amino acids from nonessential amino acids?

<p>Essential amino acids cannot be synthesized by the body and must be obtained from the diet.</p> Signup and view all the answers

The straight chain polysaccharide that forms the primary structural component of plant cell walls is ______.

<p>cellulose</p> Signup and view all the answers

Which amino acid is commonly associated with a sweet taste due to its name?

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

Amylopectin is soluble in water.

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

What type of sugars are glucose and sucrose classified as?

<p>monosaccharides and disaccharides respectively</p> Signup and view all the answers

The enzyme that breaks down glycogen to glucose when needed is ______.

<p>glycogen phosphorylase</p> Signup and view all the answers

What distinguishes amylose from amylopectin?

<p>Amylose is a long unbranched chain, whereas amylopectin has a branched structure. (C)</p> Signup and view all the answers

What is the primary dietary source of glucose for humans?

<p>Starch</p> Signup and view all the answers

What is the primary structure of proteins defined by?

<p>The specific sequence of amino acids (D)</p> Signup and view all the answers

All naturally occurring amino acids are optically active.

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

What is a zwitter ion?

<p>A dipolar ion that contains both positive and negative charges.</p> Signup and view all the answers

The peptide bond is formed between the –COOH group and the –____ group.

<p>NH2</p> Signup and view all the answers

Which structure is stabilized by hydrogen bonds and disulphide linkages?

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

Fibrous proteins tend to be soluble in water.

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

What is formed when two amino acids combine?

<p>Dipeptide</p> Signup and view all the answers

A tripeptide contains ____ amino acids.

<p>three</p> Signup and view all the answers

Which of the following is NOT a feature of globular proteins?

<p>High melting point (D)</p> Signup and view all the answers

Match the following types of protein structures with their characteristics:

<p>Fibrous proteins = Insulin and albumins Globular proteins = Keratin and myosin Primary structure = Specific sequence of amino acids Secondary structure = a-helix and b-pleated sheet</p> Signup and view all the answers

Proteins are composed of polypeptides linked by peptide bonds.

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

What does the term 'native protein' refer to?

<p>A protein that has a unique three-dimensional structure and biological activity.</p> Signup and view all the answers

A polypeptide with more than ______ amino acid residues is called a protein.

<p>100</p> Signup and view all the answers

The secondary structure of proteins commonly includes which of the following?

<p>a-helix and b-pleated sheet (D)</p> Signup and view all the answers

What happens to a protein’s structure when it is subjected to physical or chemical changes?

<p>The hydrogen bonds are disturbed, leading to denaturation.</p> Signup and view all the answers

What occurs during the denaturation of proteins?

<p>Secondary and tertiary structures are destroyed (C)</p> Signup and view all the answers

Egg white coagulation upon boiling is an example of protein denaturation.

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

What term is used for the enzymes that catalyze oxidation-reduction reactions?

<p>Oxidoreductase enzymes</p> Signup and view all the answers

Vitamins B1, B2, B6, and B12 are classified as __________ soluble vitamins.

<p>water</p> Signup and view all the answers

Match the vitamins with their deficiency diseases:

<p>Vitamin A = Night blindness Vitamin B1 = Beri beri Vitamin C = Scurvy Vitamin D = Rickets</p> Signup and view all the answers

Which of the following is a correct statement regarding enzymes?

<p>They are specific for a particular reaction and substrate. (C)</p> Signup and view all the answers

Most vitamins can be synthesized in the human body.

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

What compound is needed in small amounts in our diet to prevent specific diseases?

<p>Vitamins</p> Signup and view all the answers

The enzyme that catalyzes the hydrolysis of maltose into glucose is called __________.

<p>maltase</p> Signup and view all the answers

Match the following vitamins with their sources:

<p>Vitamin C = Citrus fruits Vitamin K = Green leafy vegetables Vitamin D = Fish and egg yolk Vitamin A = Carrots</p> Signup and view all the answers

Which configuration do compounds correlated with the D (+) isomer of glyceraldehyde have?

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

What is the main function of enzymes?

<p>To facilitate biochemical reactions (D)</p> Signup and view all the answers

Glucose can give Schiff’s test due to its aldehyde group.

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

The primary structure of a protein is altered during denaturation.

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

What forms do glucose exist in?

<p>a-form and b-form</p> Signup and view all the answers

What is formed as a result of curdling in milk?

<p>Lactic acid</p> Signup and view all the answers

The cyclic structure of glucose is called __________ structure.

<p>pyranose</p> Signup and view all the answers

The term 'vitamine' was derived from __________ and amine.

<p>vital</p> Signup and view all the answers

Match the following disaccharides with their characteristics:

<p>Sucrose = Non-reducing sugar Maltose = Reducing sugar Lactose = Found in milk Invert sugar = Obtained by hydrolysis of sucrose</p> Signup and view all the answers

Fructose has a ketonic functional group at carbon number 2.

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

What is the defining link in disaccharides formed between monosaccharides?

<p>glycosidic linkage</p> Signup and view all the answers

After hydrolysis, sucrose produces D-(+)-glucose and D-(–)-________.

<p>fructose</p> Signup and view all the answers

Match the monosaccharides with their configurations:

<p>Glucose = D-(+) Fructose = D-(–) Galactose = b-D Glyceraldehyde = D (+) and L (-)</p> Signup and view all the answers

Which property distinguishes maltose as a reducing sugar?

<p>It has a free aldehyde group at C1. (B)</p> Signup and view all the answers

The cyclic structure of fructose is a six-membered ring.

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

What is the common name for lactose?

<p>milk sugar</p> Signup and view all the answers

Anomers are isomers that differ in the configuration at the __________ carbon.

<p>anomeric</p> Signup and view all the answers

What shape does the DNA molecule take according to Watson and Crick?

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

The RNA molecule contains thymine as one of its nucleotide bases.

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

What are the three types of RNA mentioned?

<p>messenger RNA (m-RNA), ribosomal RNA (r-RNA), transfer RNA (t-RNA)</p> Signup and view all the answers

DNA fingerprinting is used for identifying __________ individuals.

<p>criminals</p> Signup and view all the answers

Match the following bases with their corresponding DNA/RNA types:

<p>Adenine = Pairs with Thymine Cytosine = Pairs with Guanine Uracil = Only in RNA Thymine = Only in DNA</p> Signup and view all the answers

What is the role of nucleic acids in the cell?

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

The sugar in DNA is ribose.

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

What unique feature does DNA fingerprinting have compared to fingerprint patterns?

<p>It cannot be altered by any known treatment.</p> Signup and view all the answers

In DNA, adenine pairs with __________.

<p>thymine</p> Signup and view all the answers

Match the following scientists with their contributions:

<p>James Watson = Proposed double helix structure Francis Crick = Co-discovered DNA structure Maurice Wilkins = Nobel prize winner Har Gobind Khorana = Worked on nucleic acids</p> Signup and view all the answers

What is the primary structure of nucleic acids?

<p>Sequence of nucleotides (B)</p> Signup and view all the answers

Hydrogen bonds in DNA are formed between specific pairs of bases.

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

Which two hormones regulate glucose levels in the blood?

<p>Insulin and glucagon</p> Signup and view all the answers

Nucleotides are joined together by __________ linkage.

<p>phosphodiester</p> Signup and view all the answers

Which of the following vitamins is fat-soluble?

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

RNA contains thymine as one of its bases.

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

What is the basic structural difference between starch and cellulose?

<p>Starch is composed of alpha-glucose units while cellulose consists of beta-glucose units.</p> Signup and view all the answers

The main female sex hormone is called __________.

<p>estradiol</p> Signup and view all the answers

Match the following hormones with their primary functions:

<p>Glucocorticoids = Control carbohydrate metabolism Estradiol = Control menstrual cycle Testosterone = Develop male characteristics Mineralocorticoids = Regulate water and salt excretion</p> Signup and view all the answers

Which of the following conditions might result from an underactive adrenal cortex?

<p>Addison's disease (C)</p> Signup and view all the answers

The secondary structure of proteins can be affected by changes in temperature and pH levels.

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

What are enzymes and why are they important in biological systems?

<p>Enzymes are biocatalysts that speed up chemical reactions in cells and are crucial for metabolic processes.</p> Signup and view all the answers

Amino acids can act as __________ because they can donate and accept protons.

<p>amphoteric</p> Signup and view all the answers

Which type of carbohydrate is considered a reducing sugar?

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

Iodized salt is used to prevent hypothyroidism caused by iodine deficiency.

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

What role does testosterone play in males?

<p>Testosterone is responsible for the development of secondary male characteristics and contributes to reproductive functions.</p> Signup and view all the answers

Proteins are polymers of _________ linked by peptide bonds.

<p>amino acids</p> Signup and view all the answers

Which process involves the hydrolysis of sucrose?

<p>Formation of glucose and fructose (A)</p> Signup and view all the answers

Flashcards

Carbohydrates

Organic compounds found in various forms like sugars, starch, etc., primarily produced by plants.

Cx(H2O)y

General formula often used to represent carbohydrates, but not all compounds fitting this formula are carbohydrates.

Hydrolysis

The process of breaking down a large molecule into simpler units by adding water.

Sugars

Carbohydrates that are sweet in taste.

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Sucrose

Common table sugar often used in homes.

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Lactose

Sugar present in cow's milk.

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Optically active

Sugars that have a specific asymmetric carbon atom and rotate plane-polarized light.

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Polyhydroxy aldehydes or ketones

Carbohydrates are defined as these or compounds that produce them upon hydrolysis.

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Monosaccharide

A carbohydrate that cannot be broken down further into simpler units.

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Oligosaccharide

A carbohydrate composed of two to ten monosaccharide units linked together.

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Disaccharide

A type of oligosaccharide containing two monosaccharide units.

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Polysaccharide

A large carbohydrate made up of many repeating monosaccharide units linked together.

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Aldose

A sugar that contains an aldehyde functional group.

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Ketose

A sugar that contains a ketone functional group.

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Number of Carbon Atoms

The number of carbon atoms present in a monosaccharide.

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Configuration

The specific arrangement of atoms in a molecule, particularly around a chiral center.

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D-Glyceraldehyde

The isomer of glyceraldehyde that rotates plane-polarized light to the right.

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Dextrose

The common name for glucose, an aldohexose.

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Hydrolysis of Starch

The process of breaking down starch into glucose using dilute acid and heat.

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Oxidation with Bromine Water

A chemical reaction where a compound reacts with bromine water, resulting in oxidation.

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Anomeric carbon

The carbon atom in a monosaccharide that was the carbonyl carbon (C=O) before ring formation.

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Anomers

Isomers of a cyclic sugar that differ in the configuration of the hydroxyl group at the anomeric carbon.

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Pyranose structure

The six-membered cyclic structure of glucose, named after the pyran molecule.

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Furanose structure

The five-membered cyclic structure of fructose, named after the furan molecule.

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Glycosidic linkage

A type of bond formed between two monosaccharides through the loss of a water molecule, involving an oxygen atom.

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Reducing sugar

Sugars that have a free reducing group (aldehyde or ketone) and can undergo oxidation.

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Non-reducing sugar

Sugars that lack a free reducing group because the anomeric carbons of both monosaccharides are involved in the glycosidic bond.

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Hydrolysis of disaccharides

The process of breaking down a disaccharide into its constituent monosaccharides by adding water.

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Invert sugar

A mixture of glucose and fructose, formed by the hydrolysis of sucrose, which is laevorotatory due to the higher laevorotation of fructose.

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Starch

A type of carbohydrate that acts as the main energy storage in plants.

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Amylose

The water-soluble component of starch, a long unbranched chain of glucose units linked by C1-C4 glycosidic bonds.

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Amylopectin

The insoluble component of starch, a branched chain of glucose units linked by C1-C4 and C1-C6 glycosidic bonds.

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Cellulose

The most abundant organic substance in the plant kingdom, a straight chain polysaccharide composed of b-D-glucose units linked by C1-C4 glycosidic bonds.

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Glycogen

The main carbohydrate storage form in animals, similar in structure to amylopectin but more branched.

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Proteins

Polymers of amino acids that play crucial roles in structure and function in living organisms.

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Amino Acids

The building blocks of proteins, containing an amino group (–NH2), a carboxyl group (–COOH), and a side chain (R).

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Amino Acid Classification

The classification of amino acids based on the relative number of amino and carboxyl groups.

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Essential Amino Acids

Amino acids that cannot be synthesized by the body and must be obtained through diet.

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Zwitter Ion

A dipolar ion formed when an amino acid in an aqueous solution loses a proton from its carboxyl group and gains a proton on its amino group.

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Amphoteric Behaviour

The ability of a substance to act as both an acid and a base.

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Chiral Center

An asymmetric carbon atom in a molecule that allows for different spatial arrangements of its substituents, leading to optical activity.

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Primary Protein Structure

The specific arrangement of amino acids in a polypeptide chain, forming the basis of the protein's structure and function.

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Secondary Protein Structure

The three-dimensional shape of a polypeptide chain, formed by hydrogen bonding between amino acid residues.

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Tertiary Protein Structure

The overall three-dimensional shape of a protein, determined by interactions between amino acid side chains.

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Quaternary Protein Structure

The arrangement of multiple polypeptide chains (subunits) in a protein, forming its final functional structure.

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Fibrous Protein

A type of protein with polypeptide chains running parallel, held together by hydrogen bonds and disulfide bridges, forming a fibrous structure.

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Globular Protein

A type of protein characterized by a spherical or globular shape, formed by the folding of polypeptide chains.

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Peptide Bond

A bond formed between the carboxyl group of one amino acid and the amino group of another amino acid, linking them together in a polypeptide chain.

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Dipeptide

A molecule formed by the condensation reaction of two amino acids, linked by a single peptide bond.

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Polypeptide

A polymer of multiple amino acids linked by peptide bonds.

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Native Protein

A protein in its natural, functional three-dimensional conformation.

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DNA

A type of nucleic acid found in the nucleus of cells, responsible for storing and transmitting genetic information.

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RNA

A type of nucleic acid involved in protein synthesis, carrying genetic information from DNA to ribosomes.

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Nucleotide

The building blocks of nucleic acids, consisting of a nitrogenous base, a five-carbon sugar, and a phosphate group.

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Enzyme

A type of protein that acts as a biological catalyst, accelerating chemical reactions in living organisms.

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Denaturation

A process in which a protein loses its functional structure, usually due to changes in temperature, pH, or other factors.

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Vitamins

Organic compounds required in small amounts by the body for various metabolic processes, often obtained through diet.

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Hormones

Organic compounds produced by the body or taken as dietary supplements, used for various physiological functions, regulating growth, metabolism, and reproduction.

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Steroid hormones

A group of hormones produced by the adrenal cortex, playing crucial roles in carbohydrate metabolism, stress response, and electrolyte balance.

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What are the two main types of nucleic acids?

Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two main types of nucleic acids.

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Why are nucleic acids called polynucleotides?

Nucleic acids are long chain polymers of nucleotides, and thus they are also called polynucleotides.

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What is the significance of Watson and Crick's discovery?

The discovery of DNA's double helix structure by Watson and Crick revolutionized biology.

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Describe the structure of DNA.

DNA's double helix structure resembles a twisted ladder, with alternating phosphate and deoxyribose sugar units forming the rails and base pairs forming the rungs.

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What are the four bases in DNA?

Adenine (A), Guanine (G), Cytosine (C), and Thymine (T) are the four bases found in DNA.

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What are the four bases in RNA?

RNA also contains four bases, Adenine (A), Guanine (G), Cytosine (C), and Uracil (U).

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What is a nucleoside?

A nucleoside is formed when a base attaches to the 1' position of a sugar.

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What is a nucleotide?

A nucleotide is formed when a nucleoside is linked to a phosphate group at the 5' position of the sugar.

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How are nucleotides linked together?

Nucleotides are linked together by phosphodiester bonds between the 5' and 3' carbon atoms of the sugar.

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What is the primary structure of nucleic acids?

The sequence of nucleotides in a nucleic acid chain is called its primary structure.

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What is the secondary structure of DNA?

The double helix structure of DNA is its secondary structure.

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Explain the base pairing rule in DNA.

DNA's two strands are complementary due to specific hydrogen bonds formed between the base pairs: Adenine pairs with Thymine, and Cytosine pairs with Guanine.

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What is the secondary structure of RNA?

RNA exists as single-stranded helices that can fold back on themselves.

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What are the three types of RNA?

Messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA) are the three types of RNA.

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What is DNA fingerprinting?

DNA fingerprinting is a technique that utilizes the unique DNA sequence of an individual for identification purposes.

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Protein Denaturation

The process that alters a protein's structure, disrupting its biological function. This occurs when conditions like heat or pH changes cause secondary and tertiary structures to break down.

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Globules unfold in protein denaturation

The unfolding of a protein's structure, causing loss of function.

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Helix uncoiling in protein denaturation

The process of uncoiling a protein helix, leading to loss of function.

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What is an enzyme?

A type of protein that acts as a biological catalyst, speeding up reactions in living organisms without being consumed in the process.

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Enzyme Specificity

Enzymes are highly specific, meaning each enzyme usually interacts with only one or a small group of molecules called substrates.

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What is a substrate?

This refers to the substance that an enzyme binds to and acts upon, transforming it into a product.

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How do enzymes work?

Enzymes lower the activation energy needed for a reaction to occur, therefore speeding up the reaction.

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Fat-soluble vitamins

Vitamins that dissolve in fats and oils, but not in water.

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Water-soluble vitamins

Vitamins that dissolve in water. These must be consumed regularly as they are not stored in the body.

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Heredity

The study of how traits are passed from one generation to the next.

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Chromosomes

Structures found within the nucleus of cells, responsible for transmitting genetic information.

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Nucleic acids

A type of biomolecule that plays a vital role in heredity, alongside proteins.

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Primary structure of a protein

The primary structure of a protein refers to the specific sequence of amino acids in the polypeptide chain. This sequence is determined by the genetic code.

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Secondary structure of a protein

The secondary structure of a protein involves the folding of the polypeptide chain into specific shapes, such as alpha-helices and beta-sheets. These structures are stabilized by hydrogen bonds.

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Study Notes

Biomolecules

  • Living systems are made of non-living atoms and molecules
  • Biochemistry is the study of chemical processes in living systems
  • Biomolecules include carbohydrates, proteins, nucleic acids, and lipids
  • Proteins and carbohydrates are essential in our diet
  • Simple molecules like vitamins and minerals are also important

Carbohydrates

  • Primarily produced by plants
  • General formula: Cx(H2O)y
  • Examples: cane sugar, glucose, starch
  • Classified by their behavior on hydrolysis
    • Monosaccharides: Cannot be hydrolyzed further (glucose, fructose, ribose)
    • Oligosaccharides: Yield 2-10 monosaccharides on hydrolysis (e.g., disaccharides)
    • Polysaccharides: Yield many monosaccharides on hydrolysis (starch, cellulose, glycogen)
  • Reducing sugars reduce Fehling's and Tollens' reagents; all monosaccharides are reducing sugars
  • Classification of monosaccharides based on carbon number and functional group (aldose or ketose)
  • Glucose is an aldohexose, also known as dextrose, monomer of starch and cellulose
  • Glucose exists as cyclic hemiacetal structures (α- and β-forms)
  • Fructose is a ketohexose, naturally occurring monosaccharide
  • Disaccharides: Formed by glycosidic linkages between monosaccharides (e.g., sucrose, maltose, lactose)
    • Sucrose: Non-reducing sugar, formed from glucose and fructose
    • Maltose: Reducing sugar, formed from two glucose units
    • Lactose: Reducing sugar, formed from galactose and glucose
  • Polysaccharides: Larger polymers of monosaccharides (starch, cellulose, glycogen)
    • Starch: Plant storage polysaccharide, amylose (unbranched) and amylopectin (branched)
    • Cellulose: Plant structural polysaccharide, linear chain of β-D-glucose units
    • Glycogen: Animal storage polysaccharide, highly branched, similar to amylopectin

Proteins

  • Most abundant biomolecules in living systems
  • Derived from Greek word "proteios"
  • Polymers of α-amino acids
  • Amino acids contain amino and carboxyl groups, α-amino acids are obtained from hydrolysis
  • Amino acids are classified as acidic, basic, or neutral
  • Essential amino acids cannot be synthesized in the body and must be obtained through diet
  • Amino acids exist in zwitterionic form in aqueous solution
  • Proteins are classified as fibrous or globular based on shape
  • Structure of proteins studied at four levels: primary, secondary, tertiary, and quaternary
    • Primary: Sequence of amino acids
    • Secondary: Structures like α-helix and β-pleated sheets due to hydrogen bonds
    • Tertiary: Overall 3D folding of the polypeptide chain (stabilized by hydrogen bonds, disulfide linkages, and other forces)
    • Quaternary: Arrangement of multiple polypeptide chains
  • Denaturation: Loss of secondary and tertiary structure, but primary structure remains intact, caused by pH changes or temperature

Enzymes

  • Biocatalysts that speed up reactions in living systems
  • Mostly globular proteins
  • Highly specific for a particular reaction and substrate
  • Named after the compound or reaction they catalyze
  • Reduce activation energy

Vitamins

  • Organic compounds required in small amounts
  • Classified as fat-soluble (A, D, E, K) or water-soluble (B group and C)
  • Water-soluble vitamins must be supplied regularly

Nucleic Acids

  • Polymers of nucleotides
  • DNA: Deoxyribonucleic acid, double helix structure, genetic code for proteins
  • RNA: Ribonucleic acid, single strand, involved in protein synthesis
  • Nucleotide structure: base + sugar + phosphate
  • Nucleosides: base + sugar
  • Complementary base pairing (DNA): A-T, C-G
  • Types of RNA: mRNA, rRNA, tRNA

Hormones

  • Intercellular messengers
  • Produced by endocrine glands
  • Diverse chemical nature (steroids, polypeptides, amino acid derivatives)
  • Regulate biological activities, maintain balance in the body. Examples include insulin, glucagon, and sex hormones.

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Test your knowledge on carbohydrates with this quiz that explores their classification, sweet varieties, and molecular structures. Covering concepts from monosaccharides to polysaccharides, this quiz also addresses key reactions and definitions related to carbohydrates. Perfect for biology or chemistry students looking to reinforce their understanding.

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