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Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

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Dr. Amina R ELGezeery Biochemistry Dept King Saud
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Page 1: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Dr. Amina R ELGezeery

Biochemistry Dept King Saud University

Page 2: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Continuous Assessment Tests (CAT)

•Two Tests --------------------------40 Marks •Two Quiz --------------------------10

Marks •Final----------------------------------

50 Marks •Dates for CAT:

–1st CAT: … Saturday 22 Dhu-Al-Qadah 1431 – 2nd CAT: Saturday ……… 5 Muharram 1432Time: 12-1.00Lecture Room: To be announced

Page 3: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Ref.Books

•Biochemistry by •Lehninger: Pronciples of

Biochemistry by DL. Nelson and MI. Cox-Biochemistry : Lippincott illustrated reviews . By : Champe P.C & Harvey R.A

Page 4: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Biochemistry can be defined as the science concerned with the chemical basis of lifeThe cell is the structural unit of living

systems. Thus, biochemistry can also be described as the science concerned with the chemical constituents of living cells and with the reactions and processes they undergo.

Biochemistry

Page 5: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

The Aim of Biochemistry Is to Describe &Explain, in Molecular Terms, All Chemical Processes of Living Cells

Page 6: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Biochemistry describes in molecular terms the structures,mechanisms, and chemical processes shared by all organisms and provides organizing principles that underlie life in all its diverse forms, principles we refer to collectively as the molecular logic of life.

Biochemistry provides important insights and practical applications in medicine, agriculture, nutrition, and Industry.

Page 7: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Outline of lectures 1-6

Page 8: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

What is matter?

Page 9: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

What is matter made of?

Page 10: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Common Elements

Page 11: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

What are elements made of?

Page 12: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Atomic Structure

Page 13: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Structure of an Atom

Page 14: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Elements in Living and Non- Living Materials

Page 15: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Living and Non-living

Page 16: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Distinctive Properties of Living SystemsSystems

Page 17: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Properties of Life

Page 18: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 19: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

The hirerarchy in the molecular

organization of cells

Page 20: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 21: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Organization Organismal level

Page 22: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 23: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

The Levels of organization in cells

Page 24: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Structural hierarchy in the molecular organization of cells In this plant cell, the nucleus is an organelle containing several types of supramolecular complexes, including chromosomes. Chromosomesconsist of macromolecules of DNA and many different proteins.Each type of macromolecule is made up of simple subunits—DNA of nucleotides (deoxyribonucleotides), for example.

Page 25: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 26: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

BiomoleculesFour major classes:

Page 27: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 28: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Polymers ands Monomers

Each of these types of biomolecules are polymers that are assembled from single units called monomers.

Page 29: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

BiomoleculeCarbohydrates

Lipids

Proteins

Nucleic acids

Monomer Monosaccharide

Not always polymers; Hydrocarbon chains

Amino acids

Nucleotides

Page 30: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

How do monomers form polymers??

• In condensation reactions (also called

dehydration reaction), a molecule water is removed from two monomers and they are connected together.

Page 31: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Synthesis of Polymer Dehydration

Page 32: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Hydrolysis

Page 33: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

5

60.325.5

10.52.4

Page 34: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 35: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

The four most abundant elements in living organisms, in terms of percentage of total number of atoms, are hydrogen, oxygen, nitrogen, and carbon, which together make up more than 99% of the mass of most cells. They are the lightest elements capable of forming one, two, three, and four coavelent bonds, respectively; . Thus they can react with each other to form a large number of different coavelent compounds .

Page 36: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Strengths of Bonds Common in Biomolecules

Page 37: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Organic substances are made of Carbon

Page 38: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 39: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Examples of ring & long chain carbon compounds

Page 40: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 41: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 42: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.
Page 43: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Biomolecules Are Compounds of Carbon with a Variety of Functional Groups

-The chemistry of living organisms is organized around carbon, which accounts for more than half the dry weight of cells.

Why carbon is special?

-Carbon can form single bonds with hydrogen atoms, and both single and double bonds with oxygen and .nitrogen atoms

-the ability of carbon atoms to form very stable carbon–carbon single bonds. Each carbon atom can form single bonds with up to four other carbon atoms. Two carbon atoms also can share two (or three) electron pairs, thus forming double (or triple) bonds.

Page 44: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Versatility of carbon bonding. Carbon can form covalentsingle, double, and triple bonds (in red), particularly with other carbon atoms. Triple bonds are rare in biomolecules.

Page 45: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Carbon atom posses a significant property; capacity to bond with each other . ( since a carbon atom may either accept or donate four electrons to complete an outer octet , it can form covalent bonds with other four carbon atoms )

In this way covalently linked carbon atoms can form linear or branched or cyclic backbones of different organic molecules .

Page 46: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

- The four single bonds that can be formed by a carbonatom are arranged tetrahedrally, with an angle ofabout 109.5 between any two bonds (Fig.) and anaverage length of 0.154 nm. - There is free rotation around each single bond, unless very large or highly charged groups are attached to both carbon atoms, in which case rotation may be restricted. -A double bond is shorter (about 0.134 nm) and rigid and allows little rotation about its axis . - Thus organic molecules with many single bonds can assume a number of different shapes , called conformation , depending on the degree to which each single bond is rotated .

Page 47: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

Geometry of carbon bonding. (a) Carbon atoms have a characteristic tetrahedral arrangement of their four single bonds.

(b )– , Carbon carbon single bonds have freedom of rotation as shown ) 3 3(. for the compound ethane CH OCH

) ( c D ouble bonds are shorter and . do not allow free rotation The two doubly bonded carbons and the

, , , atoms designated A B X and Y all lie in the same rigid plane.

Page 48: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

As a result , organic biomolecules have characteristic size and three dimensional conformation .

The three dimensional conformation of biomolecules is important in many aspects of biochemistry , eg. :

- In the reaction between the catalytic site of an enzyme and its substrate , the two molecules must fit each other .

- Also hormone and receptor . - Replication of DNA .

Page 49: Dr. Amina R ELGezeery Biochemistry Dept King Saud University.

.To these carbon skeletons are added groups ofother atoms, called functional groups, which conferspecific chemical properties on the molecule. It seemslikely that the bonding versatility of carbon was a majorfactor in the selection of carbon compounds for themolecular machinery of cells during the origin and evolutionof living organisms. No other chemical element can form molecules of such widely different sizes and shapes or with such a variety of functional groups.


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