What is Life Made of?Everything is made up of atoms.

Living things are made up of cells.

Cells are made up of atoms.

Lecture 2: Bio-moleculesLecture 2: Bio-molecules

Bio-moleculesBio-molecules

1.1. Structure of WaterStructure of Water

1.1. Organic molecules Organic molecules الجزيئات العضويةالجزيئات العضوية Carbohydrates Carbohydrates الكربوهيدراتالكربوهيدرات LipidsLipids الدهونالدهون ProteinsProteins البروتيناتالبروتينات Nucleic acidsNucleic acids األحماض النوويةاألحماض النووية

Life exists on Earth because of the abundant Life exists on Earth because of the abundant liquid waterliquid water..

Water has been referred to as the Water has been referred to as the universal universal solventsolvent..

Aqueous solutions:Aqueous solutions: are solutions are solutions that have materials dissolved in water)that have materials dissolved in water)

So, it has slightly So, it has slightly positivepositive and a slightly and a slightly negativenegative sides sides..

II- Water- Water

Hydrophilic Hydrophilic محب للماءمحب للماء (Glucose)(Glucose):: Is any substance that has an affinity for waterIs any substance that has an affinity for waterتحب الماءتحب الماء ..

Hydrophobic Hydrophobic كاره للماءكاره للماء (Lipid)(Lipid):: Is the substances that have no affinity for water ال تح%ب الماءال تح%ب الماء . Because

they have non-ionic and non-polar covalent bonds.– Thus, water molecules cannot form hydrogen bonds with these

molecules. AmphipathicAmphipathic كاره ومحب% للماءكاره ومحب% للماء (Phospholipid)(Phospholipid):: Has end with affinity for water and the other end with no affinity Has end with affinity for water and the other end with no affinity

for waterfor water

The Hydrophobic molecules are the major ingredients of cell membranes.

Types of solutionsTypes of solutions

Organisms are sensitive to changes in pHOrganisms are sensitive to changes in pHThe acid:The acid: Is a substance that increasesincreases the hydrogen ion

(H+) concentration in a solution. When hydrochloric acid is added to water,

hydrogen ions dissociate تنفصل from chloride ions: HCl H+ + Cl-

Addition of an acid makes a solution more Addition of an acid makes a solution more acidic.acidic.

The base:The base: Is any substance that reducesreduces the hydrogen ion

concentration in a solution. Some bases reduce H+ directly by accepting

hydrogen ions. Other bases reduce H+ indirectly by releasing

OH- that combines with H+ to form water. NaOH → Na+ + OH- OH- + H+ →

H2O

Solutions with more OHOH-- than HH++ are basic solutions.

2. Biomolecules

1. Carbohydrates2. Lipids3. Proteins4. Nucleic Acids

4 main molecules 4 main molecules involved in lifeinvolved in life

(Carbohydrates, Lipids, Proteins and nucleic acids)

Mono-mer Di-mer Poly-mer

PolymerPolymer is a long molecule consists of a chain of is a long molecule consists of a chain of similar building molecules (similar building molecules (monomersmonomers) ) covalently bounded together.covalently bounded together.

Polymer can be broken down Polymer can be broken down إلى إلى يُـكَسـًـر to its to its يُـكَسـًـرmonomers by hydrolysis (adding Hmonomers by hydrolysis (adding H22O).O).

PolymerPolymer can be can be built upbuilt up يُـبْـنَىيُـبْـنَى by linking its by linking its monomersmonomers by dehydration (removing H by dehydration (removing H22O).O).

أحادى

ثنائى

عديد

Monomers

MacromoleculeCarbohydrates

Lipids

Proteins

Nucleic acids

MonomerMonosaccharide

(sugar)

Hydrocarbon chains

Amino acids

Nucleotides

Carbohydrates

Made of: carbon, hydrogen, and oxygen atoms

Job: provide living things with energy

Examples: sugars and starches (corn, rice, potato, bread)

Consisted of few Consisted of few hundredshundreds to few to few thousandsthousands of monosaccharides. of monosaccharides.

They are two types:They are two types:1- Storage1- Storage تخزينيةتخزينية. . Provide sugarProvide sugar for cell by hydrolysis for cell by hydrolysis ماء ماء إضافة . .إضافة

asas Starch ( Starch (in plantsin plants) ) النشاالنشا and and GlycogenGlycogen (in animals) الجليكوچ%ينالجليكوچ%ين

2- Structural 2- Structural تركيبية. . Serve as Serve as building materialsbuilding materials for the organism. for the organism.

as as Cellulose in Cellulose in plants (cell wall) and plants (cell wall) and Chitin Chitin الكيتينالكيتين in the in the

cuticle الُجـلَيد of insects

Polysaccharides Polysaccharides العديد العديد السكر السكر

Lipids

Made of: long chains of carbon and hydrogen atoms (with some oxygen).

Job: store energy, repel water

Examples: fats and oils (butter, cheese, oil)

•The Fatty acid components are saturated (there is no double bonds between The Fatty acid components are saturated (there is no double bonds between the carbons. All the carbons. All CC are linked with are linked with HH. .

•Thus, it is saturated with Thus, it is saturated with HH. .

•Most animal fats are saturated. Most animal fats are saturated. •They are solid at room temperature.They are solid at room temperature.

•* Saturated fats-rich diet results in * Saturated fats-rich diet results in AtherosclerosisAtherosclerosis الشريانى الشريانى التصلب ..التصلب

•These double bonds are formed by the removal of These double bonds are formed by the removal of H H atoms.atoms.

•Most vegetable fats (oils)Most vegetable fats (oils) and and fish fatsfish fats are unsaturated. are unsaturated.

* They are liquid at room temperature.* They are liquid at room temperature.

•They can be synthetically converted to saturated (solid) by adding They can be synthetically converted to saturated (solid) by adding HH ( (Hydrogenation Hydrogenation الَهدَْرچَـةالَهدَْرچَـة). ).

B)- Un-saturated FatsB)- Un-saturated Fats الدهونالدهون مشبعة مشبعة الغيرالغير

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PhospholipidsPhospholipids have two fatty acids attached to have two fatty acids attached to glycerol and a glycerol and a phosphate groupphosphate group at the third position. at the third position. The phosphate group carries a The phosphate group carries a negativenegative chargecharge.

PhospholipidsPhospholipids Are major components of cell membranesAre major components of cell membranes

• The fatty acid The fatty acid tailstails are are hydrophobichydrophobic, but the , but the phosphate group and phosphate group and its attachments form a its attachments form a

hydrophilichydrophilic headhead..

• Thus, it is Thus, it is amphipathicamphipathic

Proteins

Made of: Nitrogen, Carbon, Hydrogen, and other atoms

Job: Many different jobs in our bodies include include structural support, storage, transport of other structural support, storage, transport of other substances, intercellular signaling substances, intercellular signaling اإلشارات بين اإلشارات بين.movement, and defense against microbes., movement, and defense against microbes ,الخلويةالخلوية

Examples: enzymes, muscles, hair

Nucleic Acids

Made of: Phosphorous, Carbon, Nitrogen, Oxygen, and Hydrogen atoms

Job: Store genetic information

Examples: DNA, RNA