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Chem-231 Foundation Biochemistry
• Sameh Sarray-Hlaoui Lectures 1 – 11 (Proteins & enzymes)
• Hayder Ahmed Lectures 12 – 23 (Carbohydrates)
• Wassim Y Almawi Lectures 24 – 32 (Lipids)
• Deeba S Jairajpuri Lectures 33 – 44 (Nitrogen metabolism)
Chem-231 Classes Schedule
• Lectures (L.H. 3) – Group : 08:30 – 09:30 Mon, Tue, Wed – Group : 09:30 – 10:30 Mon, Tue, Wed
• Tutorials (L.H. 3)
– Group A + Group B: 13:30 – 14:30 Sunday
Chem-231 Assessments
• Mid-term Exam: 2 April, 2017
• Final Exam: 28 May 2017
Chem-131 Attendance
• A minimum of 75 % attendance is required
• Tutorial attendance is compulsory
• No changing of GROUP is accepted without written authorization from the Vice-Dean for Students Affairs
CHM-231 Assessments
• All questions will be MCQ type-A – A stem followed by FIVE choices
– There is only ONE BEST choice
– Time allowed is about approx. 2.0 minutes/MCQ
• Mid-term: 70 - 75 MCQs = 150 minutes
• Final Exam: 100 = 180 minutes
CHM-231 Assessments
• Grades: – Assessment: 30 % – Final exam: 70 % Total 100 %
Textbook to use
Onedrive.live.com [email protected] Password: Student.2014
Matter Anything that has mass and volume (occupies space)
States of matter:
Solid: definite shape and volume Liquid: definite volume and takes the shape of the container Gas: takes the shape and volume of the container Plasma: indefinite shape and volume and composed by electrically charged particle (ions, electrons)
Properties of matter: Physical properties: characteristics of substance that can be measured or observed without changing the identity of the substance. Exp: color, odor, solubility, hardness, density, melting point or boiling point… Chemical properties: characteristics of substance that can not be observed without altering the substance (substance undergo a chemical reaction to form new substances)
The state of matter changes as you add more energy
Matter is composed of elements: Six elements are commonly found in living things:
H, C, N, O, P, S
Elements contain atoms An atom is the smallest piece of an element that can exist. Everything is made of atoms. All atoms have a: - Nucleus (the big bit in the middle). The nucleus contains protons and neutrons
Protons: positively charged particles (electrical charge of +1) with a mass of 1 atomic mass unit (amu). Neutrons: These have no charge; Same mass than the protons: 1 amu.
- Electrons which are negatively charged (electrical charge of -1). Particles and moves around the nucleus in orbits called shells or energy levels: labeled K, L, M, N, O, P, and Q; or 1, 2, 3, 4, 5, 6, and 7; going from innermost shell outwards.
Ion: If an atom loses or gains electrons Isotope : Same elements with same number of protons but different number of neutrons.
Exp: 12C, 13C and 14C are isotopes of carbon, all composed by 6 protons but the number of neutrons is different: 6 neutrons for 12C, 7 neutrons for 13C and 8 neutrons for 14C
When the outer shell has the maximum nb of electrons, the electron shells are said to be full. The inner shells of an atom are always full.
What are Electron Shells?
Electron structure of potassium 2,8,8,1
Electron structure of iron; 2,8,14,2
Electrons in atoms are in shells (shown as circles around the nucleus). The inner-most shell (K Shell) contains up to two electrons; Additional shells (outer shells) can contain eight electrons or more
An atom that has the maximum number of electrons in its outer
shell will be stable: This means that it will not react with other
atoms. Noble gases belongs to this group of atoms: Radon, Xenon,
Krypton, Argon, Neon, Helium.
nucleus
If the outer shell of an atom has less than its maximum number
of electrons then it will not be stable: It will react with other
atoms to get a full outer shell:
Octet rule: states that elements gain or lose electrons to
attain an electron configuration of the nearest noble gas)
Molecules & Bonds
Are (electrically) neutral group composed of two elements or more, held together by chemical bonds.
Why the elements stick together?
To achieve an octet!
Chemical Bonds
- Covalent Bonds - Non Covalent Bonds
Any time when element lose, gain or share electrons in order to get their octet, then you will have chemical bonds
Covalent Bonds
- A very strong bond; called also primary bonds
-To achieve a noble gas configuration (the octet rule), rather than losing or gaining electrons, the octet is achieved by SHARING electrons pairs. A shared electron pair is called a bonding pair.
A COVALENT BOND IS THE SHARING OF ELECTRONS BETWEEN TWO ATOMS This is covalent binding (Co= together; valent =electrons).
We use a dash as an abbreviations of the single bond X-Y In case of double bond: 2 pairs of electrons are shared
– Does not involve the sharing of electrons
– Classified into 4 categories:
Ionic bonds, Hydrophobic interactions Hydrogen bonds and Van der Waals forces,
Non-covalent Bonds
Non-Covalent Bonds
• Hydrogen Bonds – The attractive interaction of hydrogen atom with an electro-negative atom (nitrogen,
oxygen, fluorine). H bond occurs: – Stronger than a Van der Waals interaction, but weaker than covalent or ionic bonds.
• Ionic Bonds: - In ionic bond, electrons are lost or gained to achieve the octet, resulting in the formation of ions, which are attracted to each other due to having opposite charge. - These bonds are harder to break than covalent bonds (because there is a strong
electrostatic interaction between oppositely charged ions.)
• Hydrophobic interactions – Occurs when non-polar molecules (not water soluble) aggregate in aqueous
solutions in order to separate from water. – Relatively weak bond compared to normal chemical bonds
• Van der Waals forces: – Relatively weak compared to normal
chemical bonds – Depend on the relative orientation of the
molecules:
– The charge in the molecules may separate
forming a dipole.
– The dipole of one molecules does only form in
the presence of another particle.
– Each molecule will form a plus and minus pole
at the same time. The (+) side of one dipole is
attracted towards the minus side (-) of another
dipole: the molecules attract each other
THE END!
