Biomolecules macromolecules

Biomolecules

The structures Of Life.

Macromolecules• Monomers= single units• Polymer= many

monomers bound together

• Monomers, the single units, are polymerized (joined together) to form a polymer

4 Biomolecules in living things

Four groups of organic compounds found in living things are:

• carbohydrates• lipids• nucleic acids• proteins

I. Carbohydrates

• Carbohydrates • organic compound made of C, H, & O.

Carbon, hydrogen, and oxygen are usually in the ratio of 1:2:1

C6H12O6

Function of Carbohydrates

• Living things use carbohydrates as their main source of energy

• Plants and some animals use them as structural support

Examples of Carbohydrates

• Sugars– Monosaccharides– Disaccharides– Polysaccharides

3 types of sugars:

• Monosaccharides-simple sugars ( 1 sugar

carbohydrate)• Glucose &

Fructose

• Disaccharides– sucrose & Lactose ( 2

sugars linked together)

• Polysaccharides– many simple sugars

linked together

Glucose

Sucrose

Fig. 5-2a

Dehydration removes a watermolecule, forming a new bond

Short polymer Unlinked monomer

Longer polymer

Dehydration reaction in the synthesis of a polymer

HO

HO

HO

H2O

H

HH

4321

1 2 3

(a)

• A disaccharide is formed when a dehydration reaction joins two monosaccharides

• This covalent bond is called a glycosidic linkage

Animation: DisaccharidesAnimation: Disaccharides

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Fig. 5-2b

Hydrolysis adds a watermolecule, breaking a bond

Hydrolysis of a polymer

HO

HO HO

H2O

H

H

H321

1 2 3 4

(b)

Fig. 5-3

Dihydroxyacetone

Ribulose

Ket

ose

sA

ldo

ses

Fructose

Glyceraldehyde

Ribose

Glucose Galactose

Hexoses (C6H12O6)Pentoses (C5H10O5)Trioses (C3H6O3)

A monosaccharide is a

• A. carbohydrate• B. lipid• C. nucleic acid• D. protein

• A. carbohydrate

How many sugars make up a disaccharide?

• A. one• B. two• C. three• D. many

• B. two

Sugars, starches, and cellulose are all examples of which group of biomolecules?

• A. proteins• B. amino acids• C. lipids• D. carbohydrates

• D. carbohydrates

Storage Polysaccharides

• Starch, a storage polysaccharide of plants, consists entirely of glucose monomers

• Plants store surplus starch as granules within chloroplasts and other plastids

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Fig. 5-6

(b) Glycogen: an animal polysaccharide

Starch

GlycogenAmylose

Chloroplast

(a) Starch: a plant polysaccharide

Amylopectin

Mitochondria Glycogen granules

0.5 µm

1 µm

• Glycogen is a storage polysaccharide in animals• Humans and other vertebrates store glycogen

mainly in liver and muscle cells

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• Chitin, another structural polysaccharide, is found in the exoskeleton of arthropods

• Chitin also provides structural support for the cell walls of many fungi

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Fig. 5-10

The structureof the chitinmonomer.

(a) (b) (c)Chitin forms theexoskeleton ofarthropods.

Chitin is used to makea strong and flexiblesurgical thread.

Lipids• Fats, oils, waxes, steroids (examples)• Are made mostly of carbon, hydrogen, and

oxygen• Are not soluble in water (they are nonpolar)• Hydrogen : oxygen ratio is greater than 2:1

Functions of Lipids

• Used to store energy• Important part of biological membranes

Fig. 5-14

Hydrophilichead

Hydrophobictail WATER

WATER

Steroids

• Steroids are lipids characterized by a carbon skeleton consisting of four fused rings

• Cholesterol, an important steroid, is a component in animal cell membranes

• Although cholesterol is essential in animals, high levels in the blood may contribute to cardiovascular disease

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Fig. 5-15

2. Saturated Lipids : Solid fats, animals

3. Unsaturated Lipids: Oils, plants

Fig. 5-12a

(a) Saturated fat

Structuralformula of asaturated fatmolecule

Stearic acid, asaturated fattyacid

Fig. 5-12b

(b) Unsaturated fat

Structural formulaof an unsaturatedfat molecule

Oleic acid, anunsaturatedfatty acid

cis doublebond causesbending

• Hydrogenation is the process of converting unsaturated fats to saturated fats by adding hydrogen

• Hydrogenating vegetable oils also creates unsaturated fats with trans double bonds

• These trans fats may contribute more than saturated fats to cardiovascular disease

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Q. What is the difference between saturated and unsaturated fatty acids?

A. Unsaturated fatty acids have a carbon = carbon double bond.

Q. What is the difference between saturated and unsaturated fatty acids?

C10H20O2

C10H18O2

Fig. 5-11a

Fatty acid(palmitic acid)

(a) Dehydration reaction in the synthesis of a fat

Glycerol

Fig. 5-11b

(b) Fat molecule (triacylglycerol)

Ester linkage

• Biomolecules composed mainly of carbon, hydrogen, and oxygen in a ratio of 2 hydrogen for every 1 oxygen would be a ___________.

a. Carbohydrateb.Proteinsc. Amino acidsd.Nucleic acids

• A. carbohydrate

• This atom is a major part of biomolecules, or organic molecules.A. helium (He)

B. fluorine (F) C. carbon (C) D. sodium (Na)

• C. carbon

The structural component of plant cell wallsa. celluloseb.Starchc. proteinsd.Glycogen

• C. cellulose

• Which of the following is not a polymer? a. Starchb.Glucosec. Cellulosed.chitin

• A. cellulose

• On food packages, to what does the term "insoluble fiber" refer?

a. Polypeptideb.Chitinc. Starchd.Cellulose

• D. cellulose

• A molecule with the chemical formula C6H12O6 is probably a

a. Lipidb.Proteinc. Carbohydrated.None of the above

• C. carbohydrate

• Cell membranes are made ofA. many lipids called phospholipids

B. long chains of sugar C. amino acids and water

• A. many lipids called phospholipids

Which type of fat is healthy?a. Saturated fatsb.Unsaturated fats

• B . Unsaturated fats

Proteins

• Organic compound made up of: CarbonHydrogenOxygenNitrogen

3. Proteins are essential to living things:Proteins are needed to build & maintain cells, digest food, growth, insulin, antibodies for immunity, transmit heredity, movement.

4. Examples of Proteins:◊ Hemoglobin – carries O2

◊ Actin – muscle contraction

◊ Saliva (Enzyme) – breakdown Carbohydrates.

◊ Lactase (Enzyme) – digest lactose sugar

Proteins

Polymers of amino acids

Amino Acids are linked together to make proteins.

Amino acids are the monomers and proteins are the polymers.

Amino acids

• There are 20 different amino acids that are incorporated into proteins.

• All amino acids have an Amino Group (NH2), a Carboxyl group (COOH), and an R-Group (unique side chain that distinguishes that amino acid.

Amino Acid Monomers

• Amino acids differ in their properties due to differing side chains, called R groups

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Fig. 5-UN1

Aminogroup

Carboxylgroup

carbon

Fig. 5-17Nonpolar

Glycine(Gly or G)

Alanine(Ala or A)

Valine(Val or V)

Leucine(Leu or L)

Isoleucine(Ile or )

Methionine(Met or M)

Phenylalanine(Phe or F)

Trypotphan(Trp or W)

Proline(Pro or P)

Polar

Serine(Ser or S)

Threonine(Thr or T)

Cysteine(Cys or C)

Tyrosine(Tyr or Y)

Asparagine(Asn or N)

Glutamine(Gln or Q)

Electricallycharged

Acidic Basic

Aspartic acid(Asp or D)

Glutamic acid(Glu or E)

Lysine(Lys or K)

Arginine(Arg or R)

Histidine(His or H)

• The sequence of amino acids determines a protein’s three-dimensional structure

• A protein’s structure determines its function

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Four Levels of Protein Structure

• The primary structure of a protein is its unique sequence of amino acids

• Secondary structure, found in most proteins, consists of coils and folds in the polypeptide chain

• Tertiary structure is determined by interactions among various side chains (R groups)

• Quaternary structure results when a protein consists of multiple polypeptide chains

Animation: Protein Structure IntroductionAnimation: Protein Structure Introduction

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Fig. 5-21

PrimaryStructure

SecondaryStructure

TertiaryStructure

pleated sheet

Examples ofamino acidsubunits

+H3N Amino end

helix

QuaternaryStructure

Fig. 5-21a

Amino acidsubunits

+H3N Amino end

25

20

15

10

5

1

Primary Structure

Fig. 5-21d

Abdominal glands of thespider secrete silk fibers

made of a structural proteincontaining pleated sheets.

The radiating strands, madeof dry silk fibers, maintain

the shape of the web.

The spiral strands (capturestrands) are elastic, stretching

in response to wind, rain,and the touch of insects.

Fig. 5-21f

Polypeptidebackbone

Hydrophobicinteractions andvan der Waalsinteractions

Disulfide bridge

Ionic bond

Hydrogenbond

Sickle-Cell Disease: A Change in Primary Structure

• A slight change in primary structure can affect a protein’s structure and ability to function

• Sickle-cell disease, an inherited blood disorder, results from a single amino acid substitution in the protein hemoglobin

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Fig. 5-22c

Normal red bloodcells are full ofindividualhemoglobinmolecules, each carrying oxygen.

Fibers of abnormalhemoglobin deformred blood cell intosickle shape.

10 µm 10 µm

What Determines Protein Structure?

• In addition to primary structure, physical and chemical conditions can affect structure

• Alterations in pH, salt concentration, temperature, or other environmental factors can cause a protein to unravel

• This loss of a protein’s native structure is called denaturation

• A denatured protein is biologically inactive

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5. All chemical reactions that take place in the body are controlled by enzymes and all enzymes are proteins.

Which of the following is NOT a function of proteins?

• A. store and transmit heredity in the form of a chemical code

• B. Help to fight disease (antibodies for immunity)

• C. Control the rate of reactions and regulate cell processes

• D. Build tissues such as bone and muscle

Answer

• A. store and transmit heredity in the form of a chemical code

___ link together to make up proteins.

• A. sugars• B. lipids• C. amino acids• D. nucleic acids

Answer

• C. amino acids

If you were trying to identify a structural formula as protein, what would you look for?

• A. less than 2:1• B. greater than 2:1• C. 2:1• D. an NH2 & -COOH group, which are known as

an amino group and a carboxyl group

• D. an NH2 & -COOH group, which are known as an amino group and a carboxyl group

D. Nucleic Acids

• Function- transmits and stores genetic information

• Composed of C, H, O, N & P (Phosphorous).

Structure of a nucleotide, the monomer of a nucleic acid

2 types of Nucleic acids

• 1) Deoxyribonucleic acid– Contains the sugar deoxyribose– Double stranded

• 2)Ribonucleic acid– Contains the sugar ribose– Single stranded

Fig. 5-26-1

mRNA

Synthesis ofmRNA in thenucleus

DNA

NUCLEUS

CYTOPLASM

1

The Structure of Nucleic Acids

• Nucleic acids are polymers called polynucleotides

• Each polynucleotide is made of monomers called nucleotides

• Each nucleotide consists of a nitrogenous base, a pentose sugar, and a phosphate group

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Fig. 5-27

5 end

Nucleoside

Nitrogenousbase

Phosphategroup Sugar

(pentose)

(b) Nucleotide

(a) Polynucleotide, or nucleic acid

3 end

3C

3C

5C

5C

Nitrogenous bases

Pyrimidines

Cytosine (C) Thymine (T, in DNA) Uracil (U, in RNA)

Purines

Adenine (A) Guanine (G)

Sugars

Deoxyribose (in DNA) Ribose (in RNA)

(c) Nucleoside components: sugars

Fig. 5-27c-1

(c) Nucleoside components: nitrogenous bases

Purines

Guanine (G)Adenine (A)

Cytosine (C) Thymine (T, in DNA) Uracil (U, in RNA)

Nitrogenous bases

Pyrimidines

E. Testing summary for Biomolecules1. Benedict’s solution = yellow or

reddish-orange for simple sugars.

2. Iodine solution = black for starch (complex carbohydrate)

3. Biuret solution = violet for protein.

4. Sudan IV solution = red for lipids

5. Lipids = clear or translucent spot on brown paper.

Question

• Which biomolecule is composed of carbon, hydrogen, oxygen, nitrogen, and phosphorous. It also stores and transmits genetic information?

a. Carbohydratesb.Proteinsc. Lipidsd.Nucleic acids

Answer

• D. nucleic acids

DNA & RNA are two types of ____

• A. carbohydrates• B. nucleic acids• C. proteins• D. lipids

• B. nucleic acids

All chemical reactions that take place in the body are controlled by

• A. enzymes• B. lipids• C. sugars• D. RNA

Answer

• A. enzymes

Which group of biomolecules do enzymes belong to?

a. Lipidsb. Carbohydratesc. Proteinsd. Nucleic acids

Answer

• C. proteins

Which biomolecule does deoxyribonucleic acid belong to?• A. carbohydrates • B. lipids • C. proteins • D. nucleic acids

• D. nucleic acid

Which monomers contain N?• A. carbohydrates • B. lipids • C. proteins • D. nucleic acids

• C & D- proteins, nucleic acids

Some of these are inorganic • A. carbohydrates • B. lipids • C. proteins • D. none

• D. none

Contain carbon, hydrogen and oxygen• A. carbohydrates • B. lipids • C. proteins • D. nucleic acids • E. all of the above

• E. all of the above

Contain all the elements C,H, O, N, and P • A. carbohydrates • B. nucleic acids • C. proteins • D. lipids • E. none

• B. nucleic acids

Examples are glucose, sucrose, and maltose • A. carbohydrates • B. lipids • C. proteins • D. nucleic acid • E. none

• A. carbohydrate

Fats, oils, and waxes • A. carbohydrates • B. lipids • C. proteins • D. nucleic acids • E. none

• B. lipids

Monomers made of sugar, N-base, and phosphate • A. carbohydrates • B. lipids • C. nucleic acid • D. protein• E. none

• C. nucleic acid

Enzymes are• A. carbohydrates • B. proteins • C. lipids• D. nucleic acids • E. none

• B. proteins

THEEND