macro molecules

All LIVING things are mostly made of 4 types of

molecules called BIOMOLECULES.

BIOMOLECULES are very large molecules of many ATOMS covalently bonded together

All BIOMOLECULES contain CARBON (C)

Organic Organic CompoundsCompounds

CompoundsCompounds that contain CARBONCARBON are called organicorganic.

MacromoleculesMacromolecules are large organic moleculesorganic molecules.

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CarbonJust like water carbon is very important to life

Most molecules of the cell are carbon-based

Molecules in the cell are called biomolecules

These consist of a backbone of carbon atoms

Atoms of other elements may branch off this backbone

This is the basic structure of most of the molecules in our bodies

Carbon (C)Carbon (C)CarbonCarbon has 4 electrons4 electrons in

outer shell.

CarbonCarbon can form covalent covalent bondsbonds with as many as 4 4 other atoms (elements).

Usually with C, H, O or NC, H, O or N.

Example:Example: CHCH44(methane)(methane)5

Why are carbon atoms so common in living things?

Because carbon is a very versatile elementLets look at the element carbon

It has 4 electrons on it’s outer shell/energy level

This means it can form up to four bonds with other atoms

Carbon-based molecules are called organic moleculesNon- carbon based molecules are called……

Inorganic molecules e.g. water, oxygen, ammonia

Monomers & Polymers Some biomolecules consist of hundreds or even millions of

atoms

Large molecules are made from smaller units called monomers

Monomers are linked to form polymers

Every cell has thousands of different polymers

All these are built from fewer than 50 monomers

Life’s large molecules are classified into 4 main categories:

carbohydrates, lipids, proteins and nucleic acids

The 4 types of biomolecules often consist of large carbon chains

4 categories of BIOMOLECULESproteins

carbohydrates

lipids

nucleic acids

MacromoleculesMacromolecules Large organic molecules.Large organic molecules.Also called POLYMERSPOLYMERS.Made up of smaller “building blocks” called

MONOMERSMONOMERS. Examples:Examples:

1. Carbohydrates1. Carbohydrates2. Lipids2. Lipids3. Proteins3. Proteins4. Nucleic acids (DNA and RNA4. Nucleic acids (DNA and RNA))

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CarbohydratesCarbohydrate means “hydrated” carbon

Composing elements C, H, O

Hydrogen and Oxygen are in a ratio of 2:1

Can be simple monomers like glucose

Can be complex polymers like cellulose10

CarbohydratCarbohydrateses

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CarbohydratesCarbohydrates Organic compounds made up of Sugar molecules. Contain C, H, O in the ratio 1:2:1Small sugar moleculesSmall sugar molecules to large sugar large sugar

moleculesmolecules.

Examples:Examples:A.A. monosaccharidemonosaccharideB.B. disaccharidedisaccharideC.C. polysaccharidepolysaccharide

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CarbohydratesCarbohydratesMonosaccharide: one sugar unitMonosaccharide: one sugar unit

Examples:Examples: glucose (glucose (C6H12O6)deoxyribosedeoxyriboseriboseriboseFructoseFructoseGalactoseGalactose

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glucoseglucose

CarbohydratesOrganic compounds made up of sugar moleculesContain C, H, O in the ratio 1:2:1

Monosaccharides Consist of just one sugar unitE.g. glucose, fructose and galactoseHoney contains glucose and fructoseMain fuel for cellular workCells break down glucose molecules and extract their stored energy

CarbohydratesCarbohydratesDisaccharide: Disaccharide: Made by joining 2 monosaccharides by process of

dehydration Examples:Sucrose,lactose, Examples:Sucrose,lactose, maltose maltose

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•These sugars give energy that lasts a little longer than monosaccharides because the glycosidic bond (a covalent bond between two monosaccharides) must be broken before the sugar can be used for energy

Using a dehydration reaction cells can make disaccharides from two monosaccharides

Sucrose is made from glucose and fructose

Found in plant sap

Table sugar is sucrose which comes from sugar cane

Polysaccharide: many sugar unitsPolysaccharide: many sugar units

Examples:Examples:starch (bread, potatoes), glycogen(beef muscle) starch (bread, potatoes), glycogen(beef muscle) cellulose (lettuce, corn)cellulose (lettuce, corn)

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glucoseglucoseglucoseglucose




cellulosecellulose

Polysaccharides

Also called complex carbs

Starch made of glucose monomers

Starch is found mostly in plants

Glycogen is found in animal cells

Stored in liver and muscle

Cellulose is a polysacc that acts as a building material

Commonly known as fiber

We do not have a digestive enzyme to break it down

Functions of carbohydrates. HOW DO THEY HELP THE CELL?HOW DO THEY HELP THE CELL?

Carbohydrate functions as an energy source of the body and acts as Bio fuel.

1. PROVIDE ENERGY.1. PROVIDE ENERGY.

Polysaccharide starch acts as storage food for plants.

Glycogen stored in liver and muscles acts as storage food for animals.

2. STRUCTURAL SUPPORT.2. STRUCTURAL SUPPORT.

Cellulose forms cell wall of plant cell

3. CELL-CELL COMMUNICATION.3. CELL-CELL COMMUNICATION.

Therefore the building block of Carbohydrates are sugarsTherefore the building block of Carbohydrates are sugars

LipidsLipids

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Lipids

Have you ever looked into a bottle of salad dressing….What did you notice?Lipids are hydrophobic – afraid of waterThis is very important to their functionCell membranes surround the cellLipids also make signalling molecules Form energy storage

LipidsLipids General term for compounds which are not soluble in not soluble in

waterwater. Lipids are soluble in hydrophobic solventsare soluble in hydrophobic solvents. Remember:Remember: ““stores the most energystores the most energy””

Examples:Examples: 1. Fats1. Fats2. Phospholipids2. Phospholipids3. Oils3. Oils4. Waxes4. Waxes5. Steroid hormones5. Steroid hormones6. Triglycerides6. Triglycerides

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LipidsLipidsSix functions of lipids:Six functions of lipids:

1.1. Long term Long term energy storageenergy storage2.2. Protection against heat loss Protection against heat loss (insulation)(insulation)3.3. Protection against physical shockProtection against physical shock4.4. Protection against water lossProtection against water loss5.5. Chemical messengers (hormones)Chemical messengers (hormones)6.6. Major component of membranes Major component of membranes (phospholipids)(phospholipids)

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Lipids- structureLipids- structureCComposed of 3 carbon backbone called glycerol

and 3 3 fatty acidsfatty acids.

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HH-C----O

H-C----O

H-C----O

H

glycerol

OC-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3

=

fatty acids


=

OC-CH2-CH2-CH2-CH =CH-CH

2 -CH2 -CH

2 -CH2 -CH

3

=

Fatty AcidsFatty AcidsThere are two kinds of fatty acidsfatty acids you may see these on food labels:

1.1. Saturated fatty acids:Saturated fatty acids: no double bonds (bad) no double bonds (bad) Lard and butter (solid at RT)

2.2. Unsaturated fatty acids:Unsaturated fatty acids: double bonds (good) double bonds (good) Fats found in fruit, vegetable, fish, corn oil, vegetable oil

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=saturatedsaturated

OC-CH2-CH2-CH2-CH=CH-CH

2 -CH2 -CH

2 -CH2 -CH

3=

unsaturated

Saturated fats…..take care

Diets rich in saturated fats are unhealthy….

Cause the build up of plaque-like substance in your arteries

Protein

Amino acids

Each amino acid consists of a central carbon with 4 partners

In all amino acids 3 of the partners are the same with Hydrogen Amino group – NH2 Carboxyl group – COOH

R-group is the functional group which is different in all amino acids

This is responsible for the properties of each AA

Building a protein….

Cells make proteins by linking 20 amino acids by peptide bonds.Amino acids are joined together when a dehydration reaction removes a hydroxyl group from the carboxyl end of one amino acid and a hydrogen from the amino group of another.This chain of AA’s is called a polypeptide (also known as a protein)

Proteins are made from one or more polypeptide chains.

Human body makes lots of proteins using different arrangements of amino acids

Each protein has a unique sequence of AA’s

Protein shape An chain of AA’s on it’s own cannot function.

A functional or working protein consists of polypeptide chains twisted, folded and coiled in a special way.

There are 4 levels of proteins

Four levels of protein structure Four levels of protein structure are:are:A.A. Primary StructurePrimary StructureB.B. Secondary Structure Secondary Structure C.C. Tertiary Structure Tertiary Structure D.D. Quaternary Structure Quaternary Structure 30

copyright cmassengale 31

Primary StructureAmino acids bonded together by

peptide bonds (straight chains)peptide bonds (straight chains) Amino acid sequence of the protein

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aa1 aa2 aa3 aa4 aa5 aa6

Peptide Bonds

Amino Acids (aa)

Secondary Structure - Secondary Structure - H bonds in the peptide chain backbone

3-dimensional folding arrangement of a primary structureprimary structure into coilscoils and pleatspleats held together by hydrogen bondshydrogen bonds.

Two examples:Two examples:

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Alpha HelixAlpha Helix

Beta Pleated SheetBeta Pleated Sheet

Hydrogen BondsHydrogen Bonds

Tertiary StructureTertiary StructureSecondary structuresSecondary structures bentbent and

foldedfolded into a more complex 3-D more complex 3-D arrangementarrangement of linked polypeptides

Bonds: H-bonds, ionic, disulfide Bonds: H-bonds, ionic, disulfide bridges (S-S)bridges (S-S)

Call a ““subunitsubunit””..

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Alpha HelixAlpha Helix

Beta Pleated SheetBeta Pleated Sheet

Quaternary Quaternary StructureStructure

Composed of 2 or more “subunits”Globular in shapeForm in Aqueous environmentsExample: enzymes (hemoglobin)enzymes (hemoglobin)

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subunitssubunits

Proteins (Polypeptides)Proteins (Polypeptides)Amino acids (20 different kinds of aa) bonded together by peptide bondspeptide bonds (polypeptidespolypeptides).Building blocks of Proteins are Amino Acids. Six functions of proteins :Six functions of proteins :

1.1. Storage:Storage: albumin (egg white)albumin (egg white)2.2. Transport: Transport: hemoglobinhemoglobin3.3. Regulatory:Regulatory: hormoneshormones4.4. Movement:Movement: musclesmuscles5.5. Structural:Structural: membranes, hair, nailsmembranes, hair, nails6.6. Enzymes:Enzymes: cellular reactionscellular reactions

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Functions of proteins.

Structural proteins -they form structures like hair. Horns, feather & fur.

As storage- Make up muscles and provide long term nutrient storage. (Albumin in the egg. And seeds of plants)

As Hormones – Insulin, a hormone secreted by the pancreas causes other tissues to take up glucose and regulates blood sugar concentration.

As Defense mechanism- They circulate in blood and defend from harmful microbes.(Antibodies inactivate and help destroy viruses and bacteria).

Transport – Hemoglobin a protein in blood helps carrying oxygen.

Some act as signals, conveying messages from cell to cell.

As enzymes -A group of proteins controls the chemical reactions in a cell.(enzymes) 37

Nucleic AcidsNucleic Acids• There are two types of nucleic acids

– Deoxyribonucleic acid (DNA)– Ribonucleic acid (RNA)

• Each nucleic acid is made of monomers called nucleotides

• Each nucleotide consists of

phosphate groupphosphate group

pentose sugar (5-carbon)pentose sugar (5-carbon)

nitrogenous bases:nitrogenous bases:

adenine (A)adenine (A)

thymine (T) DNA onlythymine (T) DNA only

uracil (U) RNA onlyuracil (U) RNA only

cytosine (C)cytosine (C)

guanine (Gguanine (G

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DNA - double helixDNA - double helix

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P

P

P

O

O

O

1

23

4

5

5

3

3

5

P

P

PO

O

O

1

2 3

4

5

5

3

5

3

G C

T A

How do enzymes work? In the human body catalysts are called enzymesEach enzyme catalyzes (or speeds up) only one type of

reaction – an enzyme is specificThe molecules that an enzyme reacts with are called

substrateThe substrate fits exactly into a part of the enzyme called the

active site.Sucrase is an enzyme that breaks down Sucrose into

glucose and fructose


SubstrateEnzyme Active site

Question:Question:How Are How Are

MacromoleculMacromolecules Formed es Formed

and broken?and broken?

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Dehydration Synthesis

&Hydrolysis

Dehydration SynthesisDehydration Synthesis

Also called ““condensation condensation reactionreaction””

Forms polymerspolymers by combining monomersmonomers by ““removing removing waterwater””.

43HO H

HO HO HH

H2O

Most macromolecules are made from single subunits, or building blocks, called monomers.

The monomers combine with each other using covalent bonds to form larger molecules known as polymers.

In doing so, monomers release water molecules as byproducts. This type of reaction is known as dehydration synthesis, which

means “to put together while losing water.”

Question:Question: How are Macromolecules separated or How are Macromolecules separated or digested?digested?

Hydrolysis - Polymers are broken down into monomers in a process known as hydrolysis, which means “to split water,” a reaction in which a water molecule is used during the breakdown

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Answer: Answer: HydrolysisHydrolysis

Separates monomersmonomers by ““adding wateradding water””

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HO HO HH

HO H

H2O

macro molecules

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