Biomolecules (Learning Objectives)• Learn the elements present in biomolecules and the difference monomers and

polymers.• Explain the role of water in synthesis and breakdown of polymers. • List the four major complex biomolecules found in living cells, three of which are

found on food labels and the basis for grouping of biomolecules into those four groups.

• For each group of biomolecules learn the name of its generic monomer and polymer and their function.

Carbohydrates: o Identify their chemical elements and the difference between simple sugars and complex

carbohydrates. On the food labels, what do sugar or sugar alcohol, and fiber refer to.o Compare and contrast the structure and function of the following carbohydrates and where

they are found: glucose, glycogen, starch, cellulose, chitin.

Proteins: o Identify their chemical elements and functional groups .Recognize the structure of an

amino acid and the peptide bond that connects di-, tri, and polypeptides. Recognize the presence of 20 amino acids and that not all are essential amino acids.

o Summarize the function of proteins and recognize the importance of the three dimensional shape of a protein on its function and the role of non-covalent bonds in maintaining the shape of a protein.

o Explain protein denaturation and the effect of heat on protein structure and function.

Biomolecules (Learning Objectives) (cont’d)

Lipids: o Identify their chemical elements and learn their property of insolubility in water. o Identify the three groups of lipids.o Compare and contrast saturated, mono-unsaturated, and poly-unsaturated fatty acids.

Explain the importance of poly-unsaturated fatty acids and why omega-3 and omega-6 fatty acids are considered essential. List sources of polyunsaturated fatty acids.

Nucleic Acids: o Identify their chemical elements and components of a nucleotide. o Describe the function of DNAo Compare and contrast the 2 types of nucleic acids : DNA and RNA.

Atoms/Elements

Molecules

Organelle

Cell

Tissue

Organ

Organ system

Organism(Family)

Population

Community

Ecosystem

Biosphere

Chemical world

Biological W

orld

Non-living

Living

Ascending

Descending

99 % of living material is made of SPONCH atoms

Other vital minerals

Chemical Elements of Biomolecules:

Diversity of organic molecules: variation in length and arrangement of carbon skeletons

Hydrocarbons (Carbon and Hydrogen only)

Functional groups add

to the structural diversity

Female lion

Estradiol

HO

OH

OH

O Testosterone

Male lion

H

OH HOH

H OH

Unlinked monomer

Dehydration reaction

Longer polymer

Short polymer

OH H

H OH

Unlinked monomer

Dehydration reaction

Short polymer

H2O

H

H2O

OH

H OHOH H

Hydrolysis

Synthesis or making

Breakdown or breaking

Role of Water in Polymer Synthesis and Breakdown

Mono- oneDi- twoTri- threeTetra- fourPenta- fiveHexa- six

Poly- many

Example of nutritional information on packaged macaroni and cheese

Single Serving %DV Double Serving %DVServing Size 1 cup (228g) 2 cups (456g)

Calories 250 500

Calories from Fat 110 220

Total Fat 12g 18% 24g 36%

Trans Fat 1.5g 3g

Saturated Fat 3g 15% 6g 30%

Cholesterol 30mg 10% 60mg 20%

Sodium 470mg 20% 940mg 40%

Total Carbohydrate 31g 10% 62g 20%

Dietary Fiber 0g 0% 0g 0%

Sugars 5g 10g

Protein 5g 10g

Vitamin A 4% 8%

Vitamin C 2% 4%

Calcium 20% 40%

Iron 4% 8%

Food consists of simple and complex biomolecules

Four Groups 1. Carbohydrates: simple sugars & complex carbs2. Lipids: triglycerides, phospholipids, steroids3. Protein4. Nucleic acids: DNA & RNA

Vitamins (other organic molecules)Minerals- chemical elements

Carbohydrates: Simple Sugars• Made of units named saccharide: one unit (mono) or two (di)• Taste sweet because they bind to “sweet” receptors on the

tongue• Broken down and digested very quickly for use as source of

energy• Examples sugars found in: blood, fruit juice, honey, milk, table

sugar, malt

Glucose Fructose Galactose

Sugar Carbohydrate Monosaccharide or disaccharide

Honey Fructose and glucose Monosaccharides

Corn syrup Glucose Monosaccharide

Fruit sugar Fructose Monosaccharide

Malt sugar Maltose Disaccharide (glucose and glucose)

Milk sugar Lactose Disaccharide (glucose and galactose)

Beet sugar (cane sugar) Sucrose Disaccharide (fructose and glucose)

Maple syrup Sucrose Disaccharide (fructose and glucose)

Examples of simple sugars and composition

Not all sweeteners are sugars

Aspatame: two connected amino acids (aspartic acid/phenylalanine di-peptide)

Saccharine: C7H5NO3S

Sucralose: chlorinated sucrose

Carbohydrates: Polysaccharides are long chains of manyunits of simple sugars

• Storage of energy: Starch (plants) and glycogen (animals)• Structures: Cellulose (plant cell walls) and chitin (insect

exoskeletons)

Starch granules in potato tuber cells

Glycogen granules in muscle tissue

Cellulose fibrils in a plant cell wall

Glucose monomer

Cellulose molecules

STARCH

GLYCOGEN

CELLULOSE

O O

OOOOOO

O O O

OOO

OOOO

OOOO

OO

OOO

OO

OOOO O

OOOOOOO

OOOOOO

OH

OH

Proteins: • Polymers of 20 amino acids• Carry out most of the functions of the cell

1. Storage2. Structural3. Transport4. Enzymes5. Hormones6. Receptors7. Contractile

Proteins

• Monomers: 20 called amino acids.• Polymers: polypetides, peptide bonds connect the

amino acids• complex three-dimensional shape or conformation.• May consist of one or more polypeptides

- Amino acid structure: a central carbon connected to• An amino group (NH2)• A carboxyl group (COOH)• An R group, different in each of the 20 different amino acids

- Chemical properties of each amino acid is determined by its R group

H

H

N

H

C

R

C

O

OH

Aminogroup

Carboxyl (acid)group

Examples of Amino Acids

H

H

N

H

C

CH2

CH

CH3 CH3

C

O

OH

H

H

N C

H

CH2

OH

C

O

OH

H

H

N C

H

C

O

OHCH2

C

OH O

Leucine (Leu) Serine (Ser) Aspartic acid (Asp)

Hydrophobic Hydrophilic

Amino acids are linked together by a peptide bond

H

HN C C

O

OH H

HN+ C

H

R

CO

OHH2O

H

H

N C C N C C

R H R OH

O

Peptidebond

DipeptideAmino acid

Dehydrationreaction

Amino group

H

R

Amino acid

Carboxyl group

H O H

Interactions between R groups gives the polypeptide a three dimensional shape

•Some proteins are made of a single polypeptide others of more than one

Collagen is a fibrous protein of three polypeptides that are supercoiled like a rope.

Hemoglobin is a globular protein with two copies of two kinds of polypeptides.

• Essential Amino acids

http://www.biology.arizona.edu/biochemistry/problem_sets/aa/aa.html

• Discovering Nutrition - Google Books Resultby Paul M. Insel, R. Elaine Turner, Don Ross - 2005 - Medical - 646 pages

• Physical and chemical conditions affecting the bonds folding the structure of a protein can change its conformation (pH, salt concentration, temperature), or denature it.

Functionally active Functionally inactive

www.pdb.org catalase (7cat)

Lipids - Three major groups of diverse water insoluble (hydrophobic) biomolecules

• Simple fats (glycerides)- long term energy storage(Glycerol + fatty acids)

• Phospholipids- make up cell membranes(Glycerol + fatty acids + phosphate + another group)

• Steroids- regulation (4 fused rings with added functional groups)

Simple Fat: fatty acids joined to glycerol

The same or different fatty acid may be present

Glycerol Fatty Acids

Fatty acids may vary in:- length of hydrocarbon chain (number of carbons).- presence, number, and locations of double bonds.

Saturated fatty acids Unsaturated fatty acids

carbon-carbon double bonds

Absent Present

Physical state at room temperature

Solid Oil

Polyunsaturated fatty acids

Chemical structure of docosahexaenoic acid, or DHA (22:6n-3), and eicosapentaenoic acid, or EPA (20:5n-3).

Enhanced by Neuroinformationhttp://lansbury.bwh.harvard.edu/polyunsaturated_fatty_acids.htm

http://www.omega3sealoil.com/Chapter2a.html

difference between omega 3, 6, and 9.

Polyunsaturated fatty acids

Key omega-3 and omega-6 fatty acids - found in oily cold-water fish:

tuna, salmon, and mackerel- Fresh seaweed- Plant sources:

Leafy greens, nuts, seeds

Omega-9 are not essential in humans

Phospholipids:- Made of glycerol with two attached fatty acids and a

phosphate group connected to a Choline group at the third position

- Major component of the cell membrane

Steroids- carbon skeleton consisting of four fused carbon rings.– cholesterol (component of cell membranes of animal cells) and

some regulatory hormones

Nucleic Acids: Informational biomolecules

• Polymers of nucleotides: deoxyribonucleotides &

ribonucleotides.

• Direct the activities and functions within a single cell.

• Store and transmit hereditary information.

• Two types of Nucleic acids: DNA and RNA.

The monomers of nucleic acids are nucleotides, consisting of :

• sugar • phosphate• nitrogenous base

Sugar

OH

O P O

O−

CH2

H

O

H H

OH H

H

N

N

HN

N H

HHN

Phosphategroup

Nitrogenousbase (A)

The sugar and phosphate backbone of the nucleic acids or polynucleotides

Sugar-phosphatebackbone

T

G

C

T

A Nucleotide

There are 4 nitrogen bases in DNA –

A: adenineT: thymineG: guanine C: cytosine

DNA consists of two strands of polynucleotides twisted around each other in a double helix

C

TA

GC

C G

T A

C G

A T

A

G C

A T

A TT A

Basepair

TRNA - single-stranded polynucleotide- contains uracil (U) instead of thymine (T)

– Stretches of nucleotides of a DNA molecule make up genes

– Sequence of nucleotides within genes dictate the amino acid sequences of proteins

Inborn Errors of Metabolism affect Major Biomolecules

Reading 2.1 page, 21

Examples CarbohydratesLipidsProteinsNucleic Acids