LECTURE: CHEMISTRY FOR BIOLOGY
LECTURE: CHEMISTRY FOR BIOLOGY KIRSTIN BROWN
Lecture: CHEMISTRY FOR BIOLOGY Outline: 1. Covalent bonds o What are covalent bonds? o Electronegativity o Bond polarity
2. Non-covalent bonds o Ionic bonds o Other intermolecular interactions
3. Bonds in protein structure
What are covalent bonds? When two atoms share valence electrons ▪ What are valence electrons? ➢ Electrons located in the outermost orbitals ▪ The octet rule
➢ Molecules are most stable when they share
enough electrons to fill their outermost shell.
H
C
N
O
H
C
N
O
Electronegativity The tendency of an atom in a covalent bond to pull the electrons of the bond towards itself.
Atom 1
Atom 2
Electronegativity The tendency of an atom in a covalent bond to pull the electrons of the bond towards itself.
Atom 1
Atom 2
▪ When there is a large electronegativity
Common polar covalent bonds:
difference between two atoms in a bond, the bond isN-H said N-C to be polar O-H O-C O-P S-H δ+
δ-
▪ The atoms in a polar bond have partial charges
and are called permanent dipoles
Non-covalent bonds Ionic bonds form as a result of the attraction between oppositely charged ions
Na+
Cl-
Non-covalent bonds Ionic bonds form as a result of the attraction between oppositely charged ions
Na+
Cl-
Non-covalent bonds Van der Waals interactions involve the attraction between atoms with partial charges
H
H
O H H
PD-PD
H O H
H O H C
C H H C H
PD-ID
ID-ID
Covalent vs. non-covalent bonds
Weakest
Covalent Ionic (two charged atoms interacting) Ion – Permanent Dipole (I – PD) Permanent Dipole – Permanded Dipole (PD – PD) Permanent Dipole – Induced Dipole (PD – ID) Induced Dipole – Induced Dipole (ID – ID)
Non-covalent
Strongest
Bond strength
Common polar covalent bonds: N-H N-C O-H O-C O-P S-H What is the strongest type of non-covalent interaction that can form between these 2 molecules?
Bonds in protein structure ▪ Proteins are made up of amino acids
▪ The 20 different R groups interact with each
other to give tertiary protein structure
Bonds in protein structure ▪ There are 20 different R groups
Bonds in protein structure
o
Which non-covalent interactions stabilizing the ADP molecule are the strongest?
Bonds in protein structure
o
Which non-covalent interactions stabilizing the ADP molecule are the strongest?
o
What type of non-covalent interaction is occurring between the Glutamate side chain and the ADP molecule?
Bonds in protein structure
o
Which non-covalent interactions stabilizing the ADP molecule are the strongest?
o
What type of non-covalent interaction is occurring between the Glutamate side chain and the ADP molecule?
o
Which side chain is the most important for stabilizing the adenine of the molecule, and what interaction(s) are occurring?
Bonds in protein structure
o
Which non-covalent interactions stabilizing the ADP molecule are the strongest?
o
What type of non-covalent interaction is occurring between the Glutamate side chain and the ADP molecule?
o
Which side chain is the most important for stabilizing the adenine of the molecule, and what interaction(s) are occurring?
o
What would happen if the Tyrosine was changed to a Lysine? Would ADP be more or less stabilized by the protein?
Chemistry for Biology - summary ▪ ________________ involve the sharing of electrons ▪ ________________ involve attraction between to
charged atoms
▪ _________________________ involve attraction
between partially charged atoms
▪ A large difference in __________________
between two atoms in a covalent bond causes the bond to be _______________
▪ The atoms in a polar covalent bond have
_________________________
▪ The three types of Van der Waals interactions are
called:
➢ _______________________ ➢ _______________________ ➢ _______________________
UP NEXT:
Unit 2: Cells
Lecture: CHEMISTRY FOR BIOLOGY Outline: 1. Covalent bonds o What are covalent bonds? o Electronegativity o Bond polarity
2. Non-covalent bonds o Ionic bonds o Other intermolecular interactions
3. Bonds in protein structure
What are covalent bonds? When two atoms share valence electrons ▪ What are valence electrons? ➢ Electrons located in the outermost orbitals ▪ The octet rule
➢ Molecules are most stable when they share
enough electrons to fill their outermost shell.
H
C
N
O
H
C
N
O
Electronegativity The tendency of an atom in a covalent bond to pull the electrons of the bond towards itself.
Atom 1
Atom 2
Electronegativity The tendency of an atom in a covalent bond to pull the electrons of the bond towards itself.
Atom 1
Atom 2
▪ When there is a large electronegativity
Common polar covalent bonds:
difference between two atoms in a bond, the bond isN-H said N-C to be polar O-H O-C O-P S-H δ+
δ-
▪ The atoms in a polar bond have partial charges
and are called permanent dipoles
Non-covalent bonds Ionic bonds form as a result of the attraction between oppositely charged ions
Na+
Cl-
Non-covalent bonds Ionic bonds form as a result of the attraction between oppositely charged ions
Na+
Cl-
Non-covalent bonds Van der Waals interactions involve the attraction between atoms with partial charges
H
H
O H H
PD-PD
H O H
H O H C
C H H C H
PD-ID
ID-ID
Covalent vs. non-covalent bonds
Weakest
Covalent Ionic (two charged atoms interacting) Ion – Permanent Dipole (I – PD) Permanent Dipole – Permanded Dipole (PD – PD) Permanent Dipole – Induced Dipole (PD – ID) Induced Dipole – Induced Dipole (ID – ID)
Non-covalent
Strongest
Bond strength
Common polar covalent bonds: N-H N-C O-H O-C O-P S-H What is the strongest type of non-covalent interaction that can form between these 2 molecules?
Bonds in protein structure ▪ Proteins are made up of amino acids
▪ The 20 different R groups interact with each
other to give tertiary protein structure
Bonds in protein structure ▪ There are 20 different R groups
Bonds in protein structure
o
Which non-covalent interactions stabilizing the ADP molecule are the strongest?
Bonds in protein structure
o
Which non-covalent interactions stabilizing the ADP molecule are the strongest?
o
What type of non-covalent interaction is occurring between the Glutamate side chain and the ADP molecule?
Bonds in protein structure
o
Which non-covalent interactions stabilizing the ADP molecule are the strongest?
o
What type of non-covalent interaction is occurring between the Glutamate side chain and the ADP molecule?
o
Which side chain is the most important for stabilizing the adenine of the molecule, and what interaction(s) are occurring?
Bonds in protein structure
o
Which non-covalent interactions stabilizing the ADP molecule are the strongest?
o
What type of non-covalent interaction is occurring between the Glutamate side chain and the ADP molecule?
o
Which side chain is the most important for stabilizing the adenine of the molecule, and what interaction(s) are occurring?
o
What would happen if the Tyrosine was changed to a Lysine? Would ADP be more or less stabilized by the protein?
Chemistry for Biology - summary ▪ ________________ involve the sharing of electrons ▪ ________________ involve attraction between to
charged atoms
▪ _________________________ involve attraction
between partially charged atoms
▪ A large difference in __________________
between two atoms in a covalent bond causes the bond to be _______________
▪ The atoms in a polar covalent bond have
_________________________
▪ The three types of Van der Waals interactions are
called:
➢ _______________________ ➢ _______________________ ➢ _______________________
UP NEXT:
Unit 2: Cells
