ib 2.1 molecules to metabolism + 2.3 carbohydrates and lipids + 2.4 proteins

2.1 Molecules to metabolism

2.3 Carbohydrates and lipids

2.4 Proteins

Plan

2.1 Molecules to metabolism:

1.1 Definition of a Biological Molecule

1.2 Four main types of Biological Molecules

1.3 Monomers and Polymers

2.3.1 Carbohydrates:

2.3.1.1 Functions

2.3.1.2 Monosaccharides

2.3.1.3 Disaccharides

2.3.1.4 Polysaccharides

2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids

2.3.2.3Triglycerides

2.3.2.4 Phospholipids

2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids

4.3 Polypeptides = Proteins

4.4 The peptide Bond

4.5 Primary structure of Proteins

4.6 Secondary structure of Proteins

4.7 Tertiary structure of Proteins

4.8 Quaternary structure of Proteins

4.9 Haemoglobin

4.10 Collagen

5 Conclusions and Overviews:

Xavier DANIEL, Ph.D. AS IB

- Always contain Carbon (C) and Hydrogen (H)

- Capable of forming 4 covalent bonds

- Carbon can bind with hydrogen, nitrogen, oxygen, and itself!

- Forms long chains, branched, rings, etc

Definition of a Biological Molecule 1

Organic molecule

Hemicellulose


Definition of a Biological Molecule 1

Biological Molecule

=

Organic molecule that plays a role in LIFE

Glucose

Triglyceride

Cholesterol Xavier DANIEL, Ph.D. AS IB

Definitions 1

Anabolism The making up of big molecules from small molecules

= Polymerization

Monomers to Polymers

Catabolism The breaking up of big molecules into small molecules

= Depolymerization

Polymers to Monomers

Metabolism

Catabolism + Anabolism




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Four main types of Biological Molecules 1

Carbohydrates

Proteins

Lipids

Nucleic Acids

Sugars

Glucose Galactose

Fructose Lactose

Cellulose Starch

Chitin

Haemoglobin

Collagen

Enzymes

Fats, oils, steroids

DNA

RNAs




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen




Carbohydrates

Proteins

Lipids

Nucleic Acids

Are macromolecules



Macromolecules

=

Many molecules joined together


Monomers and polymers 1

Macromolecules

=

Many molecules joined together

Polymer

Monomer


Monomer

Simple molecules

“Building blocks”

Polymer

Large molecules formed by combining monomers




Polymer Monomer

Carbohydrates

Proteins

Lipids

Nucleic Acids

Monosaccharide Polysaccharide

Amino acid Polypeptides / Proteins

Various types Various types

Nucleotide Polynucleotide



Polymer formation = Polymerization




=

Dehydration Synthesis

Process of making

(Here, the polymer)

Water will be “lost”

(Here, by the monomers)

Water will be “produced”

Enzymes are needed too Xavier DANIEL, Ph.D. AS IB



Monomer 1 Monomer 2

Polymer

New bond Xavier DANIEL, Ph.D. AS IB



Water will be “lost”

(Here, by the monomers)

Water will be “produced”

Monomer 1 + Monomer 2 = Polymer + H2O



Polymer breakdown = Depolymerization

Depolymerization



Polymer formation = Depolymerization

=

Hydrolysis

Process of destroying

(Here, the polymer)

Water is needed

Enzymes are needed too Xavier DANIEL, Ph.D. AS IB



Monomer 1 Monomer 2

Polymer

Bond is broken



Polymerization and Depolymerization

Depolymerization


Anabolism Catabolism

Anabolism + Catabolism

=

Metabolism


Polymerization and Depolymerization




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Carbohydrates 2

Composition of all Monosaccharides

Formula Cn(H2O)n

Carbon Water

Carbo hydrates Xavier DANIEL, Ph.D. AS IB

Carbohydrates 2

Three main Functions

Source of ENERGY

1 Short term energy supply

Available now

For immediate energy needs

GLUCOSE

2 Short term energy storage

Not yet available

For later needs of Energy

GLYCOGEN in Animals

STARCH in Plants

Structure Identity Tags

Plant cell wall : CELLULOSE

Insect exoskeleton: CHITIN

In the plasma

membrane


Carbohydrates 2




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Monosaccharides 2

ONE monomer

Several types of Monosaccharides in Polysaccharides


Monosaccharides 2

Formula Cn(H2O)n

n varies from 3 to 7

Most usual monosaccharides: n = 5 or 6

n Cn(H2O)n CnH2nOn

5 C5(H2O)5 C5H10O5

6 C6(H2O)6 C6H12O6


Monosaccharides 2

C5H10O5

5 atoms of carbon Pentose

“Five”

“Carbohydrate”

C6H12O6

6 atoms of carbon Hexose

“Six”

“Carbohydrate” Xavier DANIEL, Ph.D. AS IB

Monosaccharides 2

C5H10O5 Pentoses

Straight-chain form

Cyclic form


DRAW

Monosaccharides 2

Glucose: Different ways to see it


Monosaccharides 2

Glucose: Alpha or Beta position ?

Beta position:

The -OH is on the same side of the ring as the C # 6

In Haworth projection: upward projection.

Alpha position:

The -OH is on the opposite side of the ring as the C # 6

In Haworth projection : downward projection.

Depends on the position of the OH group on the Carbon 1

The alpha and beta label is not applied to any other carbon


DRAW



2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Disaccharides 2

Two monomers of Monosaccharides

=

Disaccharide

Formation of Glycosidic bond

Maltose, Lactose, Saccharose = Sucrose


Disaccharides 2

Maltose

Dehydration

Hydrolysis


2

Different kinds of Glycosidic bonds

a 1,4

Disaccharides

Maltose


Disaccharides 2

Lactose

Dehydration

Hydrolysis


Disaccharides 2

Lactose Different kinds of Glycosidic bonds

b 1,4


Disaccharides 2

Saccharose = Sucrose

Dehydration

Hydrolysis


Disaccharides 2

Saccharose = Sucrose Different kinds of Glycosidic bonds

a 1,2




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Polysaccharides 2

Polysaccharides

Many molecules of Monosaccharides together

Let’s focus on Polymers of Glucose

Starch Cellulose Chitin Glycogen

Long-term storage

of glucose

in plants

Long-term storage

of glucose

in animals

Exoskeleton

of insects

Shape of cells

in plants




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Polysaccharides 2

Starch Cellulose Chitin Glycogen


Polysaccharides 2

Different kinds of Glycosidic bonds

a 1,4

a 1,4

a 1,6

b 1,4


Polysaccharides 2

Starch Long-term storage

of glucose

in plants

Straight chains

with little branching

Amylose

Amylopectin


Polysaccharides 2

Glycogen Long-term storage

of glucose

in animals

Straight chains

with a lot of branching


Polysaccharides 2

Cellulose

Straight chains

No branching

Shape of cells

in plants


Polysaccharides 2

Chitin

Modified Glucose

Straight chains

No branching

Exoskeleton of Insects




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Lipids

Four main Functions

Source of ENERGY

Long term energy storage

Not yet available

For later needs of Energy

Protect organs Structure

Insulation

And

Padding

In the plasma

membrane

3

Compare to carbohydrates

as source of Energy


for structure

Communication

Chemical messengers

Hormones

Steroids Phospholipids Fatty Acids Fatty Acids


Lipids 3

Lipids do NOT dissolve in water

=

HYDROPHOBIC


Lipids

Four main Types

Fatty Acids Phospholipids Triglycerides

3

Steroids




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Lipids

Fatty Acids

3

Chains of Carbon + Hydrogen

ending in COOH (Carboxyl group)

Saturated

Solid at room temperature

Bad for health

Unsaturated

Liquid at room temperature

Good for health


Lipids

Fatty Acids

3

Saturated Unsaturated

Chain of

Carbon + Hydrogen

End in

COOH

Contain double bonds

AMPHIPATIC

Hydrophobic

Hydrophilic


Lipids

Fatty Acids

3

Unsaturated


Polyunsaturated

Saturated

Unsaturated Monounsaturated

Saturated Fat: • Function: tends to increase blood cholesterol levels.

• Sources: found mostly in meat and dairy products, as well as some vegetable oils, such as coconut and palm

oils (tropical oils). Butter is high in saturated fat, while margarine tends to have more unsaturated fat. Most

saturated fats tend to be solid at room temperature, with the exception of tropical oils.

Polyunsaturated Fat: • Function: tends to lower blood cholesterol levels

• Sources: found mostly in plant sources. (safflower, sunflower, soybean, corn, cottonseed)

Monounsaturated Fat: • Function: tends to lower LDL cholesterol (the "bad" cholesterol)

• Sources: found in both plant and animal products, such as olive oil, canola oil, peanut oil, and in some plant

foods such as avocado

Lipids

Fatty Acids

3




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Lipids

Triglycerides

3

One Glycerol Hydrophilic


Lipids

Triglycerides

3

One Glycerol + Three Fatty acids

Hydrophobic


Lipids

Triglycerides

3

One Glycerol + Three Fatty acids

Always the same molecule Not always the same

3 molecules

Saturated or Unsaturated


Lipids

Triglycerides

3




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Lipids

Phospholipids

3

Triglycerides that contain a Phosphate Group

One of the 3 fatty acids is replaced by a phosphate group

Variable


Lipids

Phospholipids

3

Hydrophobic tail Hydrophilic head

AMPHIPATIC Xavier DANIEL, Ph.D. AS IB

Lipids

Phospholipids

3


Lipids

Phospholipids

3

Found in the Cell Membranes




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Lipids

Steroids

3

Basic form = CHOLESTEROL

In animal membranes

Other steroids = derivatives of Cholesterol

Chemical messengers = Hormones


Lipids

Steroids

3

AMPHIPATIC

Hydrophobic

Hydrophilic


Lipids 3


Body Mass Index

Body Mass Index (BMI) is a number calculated from a person's weight

and height. BMI provides a reliable indicator of body fatness for most

people and is used to screen for weight categories that may lead to

health problems.

Lipids 3


http://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/metric_bmi_calculator/bmi_calculator.html

A common method used to assess whether a person is under- or overweight is

Body Mass Index (BMI).

BMI Classification

<20 Underweight

20-24.9 Ideal weight

25-29.9 Overweight

30-40 Obese

>40 Severely obese

Lipids 3




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Proteins

Six main Functions

Movement Structure

Inside the cell

The cell itself Many roles


and lipids

for structure

Enzymes

Speed up

chemical reactions

4

Transport

Inside the cells

Between cells

Long distance

Immunity

Fight diseases

Communication

Chemical messengers

Hormones

Compare to lipids

for communication Keratin

Collagen

Actin

Myosin

Tubulin

Many types

Organelle’s membrane proteins

Membrane proteins

Haemoglobin

Antibodies




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Proteins

The structure of Proteins

4

Monomers = Amino Acids


Proteins


4

Monomers = Amino Acids

Protein = Polymer of Amino Acids

Number of aa

1

2

3-20

Many

Amino acid Dipeptide

Polypeptide Protein


Proteins 4

Amino Acids

Alpha carbon

Radical

=

Side chain

Carboxyl

group

Amine group

Four covalent bonds

Hydrogen atom Xavier DANIEL, Ph.D. AS IB

Proteins 4

Amino Acids


Proteins 4

Amino Acids

ALL amino acids have the same Alpha carbon

ALL amino acids have the same Hydrogen atom

ALL amino acids have the same Amino group

ALL amino acids have the same Carboxyl group

Two different amino acids have different Side chains

Amino acids only differ by their Side chains


Proteins 4

Amino Acids

There are MANY amino acids in the cells

But only 20 can be found in proteins


The 20 amino acids

Proteins 4


Proteins 4

The 20 amino acids

Five groups of amino acids

Five kinds of side chains

Non polar

+ Aliphatic

Polar

+ uncharged

Aromatic Positively

charged

Negatively

charged


Proteins 4

Polar molecule

one end of the molecule has a positive electrical charge

and the other end has a negative charge

Electrons are not distributed symmetrically

Polarity of molecules

Water is polar Serine has a

polar side chain


Proteins 4


Carbon Dioxide (CO2)

is non polar

Non polar molecule

Electrons are distributed symmetrically

Glycine has a non polar

side chain


Proteins 4

Polarity of molecules Polar mixes well with polar


Proteins 4


Non polar mixes well with non polar

Polar and non polar do not mix well


Proteins 4

Aromatic or Aliphatic molecules

Contains one or more

benzene or benzene-like ring

Benzene Phenylalanine has an

aromatic side chain


Proteins 4

Aromatic or Aliphatic molecules

Does not contain any

benzene or benzene-like ring

Serine has an

aliphatic side chain Valine has an

aliphatic side chain


Proteins 4

Positively or Negatively charged molecules

Contains a positive charge

Are called basic molecules Lysine has an

positively charged side chain


Proteins 4

Positively or Negatively charged molecules

Contains a negative charge

Are called acidic molecules

Aspartate has an

Negatively charged side chain


Proteins 4

The 20 amino acids

Five groups of amino acids

Five kinds of side chains

Non polar

+ Aliphatic

Polar

+ uncharged

Aromatic Positively

charged

Negatively

charged

Glycine

Alanine

Valine

Leucine

Methionine

Isoleucine

Serine

Threonine

Cysteine

Proline

Asparagine

Glutamine

Phenylalanine

Tyrosine

Tryptophane

Lysine

Arginine

Histidine

Aspartate

(Aspartic acid)

Glutamate

(Glutamic acid)


Proteins 4

Non polar + Aliphatic amino acids

Hydrophobic

Usually found

in the center

of the protein

In membrane

proteins


Proteins 4

Polar + uncharged amino acids

Can form

hydrogen bonds

Inside a protein

Between two

proteins


Proteins 4


Two Csyteines can form disulfide bonds

Inside a protein

Between two proteins


Proteins 4


Proline has a unique structure

Causes kinks in the protein chain


Proteins 4

Aromatic amino acids


Proteins 4

Positively charged amino acids

Electric charge

depends on the pH


Proteins 4

Negatively charged amino acids

Electric charge

depends on the pH


Proteins 4




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Proteins 4

Polymerization of amino acids = Synthesis of Proteins

Bond between two amino acids = Peptide Bond


Proteins 4

Formation of Peptide Bond


Proteins 4


n amino acids

…………..

n-1 peptide bonds


Proteins 4


First

amino acid

“N-terminal”

“N-ter”

Last

amino acid

“C-terminal”

“C-ter”




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Proteins 4


Four levels

Primary

structure

Secondary

structure

Tertiary

structure

Quaternary

structure

Sequence of aa

in one protein

Folding starts

Hydrogen bonds

between aa

of the same protein

Folding continues

Covalent, Ionic

and Hydrogen bonds

+ Van der Waals forces

between aa

of the same protein

Folding continues

Covalent, Ionic

and Hydrogen bonds

between aa

of several proteins

ONE Molecule Several Molecules Xavier DANIEL, Ph.D. AS IB

Proteins 4

Sequence of aa

in one protein

Hydrogen bonds

between aa

of the same protein

Covalent, Ionic

and Hydrogen bonds

between aa

of the same protein

Covalent, Ionic

and Hydrogen bonds


between aa

of several proteins


Proteins 4


Proteins 4

The primary structure of Proteins

Linear sequence of amino acids of a protein

NH2-First aa, second aa, third aa,………last aa-COOH




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Proteins 4

The secondary structure of Proteins

Alpha helices and beta sheets

Hydrogen bonds between aa of the same protein

R are not involved


Proteins 4

The secondary structure of Proteins

Alpha helices and beta sheets




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Proteins 4

The tertiary structure of Proteins

Covalent, Ionic and Hydrogen bonds


between aa of the same protein

R are involved

Forms many shapes, such as

fibrous elongated proteins and globular compact proteins


Proteins 4

The tertiary structure of Proteins




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Proteins 4

The quaternary structure of Proteins

More than one polypeptide chain grouped together

Covalent, Ionic and Hydrogen bonds + Van der Waals

forces between aa of several proteins

R are involved

Only proteins with more than one subunit

can have a quaternary structure


Proteins 4

The quaternary structure of Proteins


Proteins 4

Sequence of aa

in one protein

Hydrogen bonds

between aa

of the same protein

Covalent, Ionic

and Hydrogen bonds

between aa

of the same protein

Covalent, Ionic

and Hydrogen bonds


between aa

of several proteins




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Proteins 4

Hemoglobin = Haemoglobin

= Hb = Hgb

Made of 4

subunits

2 a chains 2 b chains

Quaternary structure


Proteins 4

Haemoglobin

All four chains

contain a

HAEME group

Haemoglobin is a

globular protein

that contains haemes


Proteins 4

Heme = Haeme

Pyrrolic Group


Proteins 4

Heme = Haeme


Proteins 4

Why is Blood red ?

Haeme fixes Oxygen

Haemoglobin is red

Red blood cells are red

Erythrocytes

Blood is red


Proteins 4

Haemoglobin

Transports oxygen in the red blood cells

of Vertebrates

From Respiratory organs

(lungs or gills)

to other parts of the body

and collects the Carbon dioxide to bring it back

to the respiratory organs


Proteins 4

Haemoglobin and Sickle-cell Anemia A SINGLE amino acid in Haemoglobin is “wrong”


Proteins 4

Haemoglobin and Sickle-cell Anemia


B1: Biological Molecules

Plan

1 Introduction:


1.2 Carbon, Hydrogen, Oxygen and Nitrogen



2 Carbohydrates:

2.1 Functions

2.2Monosaccharides

2.3Disaccharides

2.4 Polysaccharides

2.5 Examples

3 Lipids :

3.1 Functions

3.2 Fatty acids

3.3Triglycerides

3.4Phospholipids

3.5Steroids

2

3

4

1

5

4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Haemoglobin

4.10 Collagen



Proteins 4

Collagen


Proteins 4

Collagen

Quaternary

structure


Top view Side view

Proteins 4

Rubisco ribulose-1,5-bisphosphate carboxylase/oxygenase

Fixation CO2 in photosynthesis


8 large subunits colored blue or cyan,

8 small subunits colored red.

Quaternary

structure

Proteins 4

Insulin Regulates glucose levels in blood


Quaternary

structure

Proteins 4

Immunoglobulin = Antibody Defense against non-self


Quaternary

structure

Proteins 4

Rhodopsin Pigment in retina to perceive light


Opsin

Transmembrane protein

7 transmembrane regions

+

Retinal

Covalently bound cofactor

Quaternary

structure

Proteins 4

Spider silk




2.4 Proteins

Plan






2.3.1.1 Functions




2.3.1.5 Examples

2.3.2 Lipids :

2.3.2.1 Functions

2.3.2.2 Fatty acids



2.3.2.5 Steroids

2

3

4

1

5

2.4 Proteins:

4.1 Functions

4.2 Amino acids







4.9 Hemoglobin

4.10 Collagen



Conclusions and Overviews 5


Conclusions and Overviews 5

Testing for the presence of…

Carbohydrates Proteins Lipids

Reducing/Non-reducing Sugars

Benedict’s test

Starch

Iodine Potassium test

Cellulose

Chlor-Zinc Iodine test

Hydrophobic lipids

Emulsion test

Proteins

Biuret test


Test for Reducing Sugars

(Benedict’s Test)


Is there any colour change in

tubes A and B ?

Ans: Only the mixture in tube

A has a colour change.

A B glucose

solution +

Benedict’s

solution

distilled

water +

Benedict’s

solution

water

bath

Benedict’s Test


What is the sequence of

change when there is a colour

change ?

Ans: The blue solution changes

first to green, then to a

yellow coloration and

eventually a brick-red

precipitate is produced.

A B glucose

solution +

Benedict’s

solution

distilled

water +

Benedict’s

solution

water

bath

Benedict’s Test


Test for Starch

(Iodine Test)


What is the final colour in

tube A ?

Ans: The solution in tube A

changes from brown

to blue black.

iodine solution

starch

solution

distilled

water

A B

Iodine Test


What is the purpose of

setting up tube B ?

Ans: To act as a control.

iodine solution

starch

solution

distilled

water

A B

Iodine Test


Test for Proteins

(Biuret Test)


egg white solution

1 cm3 NaOH solution

Put CuSO2 solution drop by

drop, and shake the mixture

after addition of each drop

Positive result: purple colour

Biuret Test


What colour changes in

tubes A and B ?

Ans: Mixture in tube A

changes from blue

to purple while

mixture in tube B

remains blue

without any change.

copper sulphate solution

egg white +

sodium

hydroxide

solution

water +

sodium

hydroxide

solution A B

Biuret Test


Which substance, oil or water,

leaves a permanent

translucent spot on the filter

paper ?

Ans: Oil.

Spot Test for Fat


Which test tube has an emulsion formed ?

Ans: Test tube A.

2 drops of

cooking oil

2 cm3 of

alcohol

2 cm3 of

distilled

water

after shaking to

form a clear

solution

shake and then

allow to stand emulsion

oil

water

shake and then

allow to stand

shaking

2 drops of

cooking oil 2 cm3 of

distilled

water

2 cm3 of

distilled

water

A

B

Emulsion Test for Fat


What happens to the other tube ?

Ans: The mixture separates into two layers because

fats do not dissolve in water.

2 drops of

cooking oil

2 cm3 of

alcohol

2 cm3 of

distilled

water

after shaking to

form a clear

solution

shake and then

allow to stand emulsion

oil

water

shake and then

allow to stand

shaking

2 drops of

cooking oil 2 cm3 of

distilled

water

2 cm3 of

distilled

water

A

B

Emulsion Test for Fat


ib 2.1 molecules to metabolism + 2.3 carbohydrates and lipids + 2.4 proteins

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