ch.2 and 3 Flashcards
(41 cards)
covalent bond
strong chemical bond where two atoms share electrons with eachothother
nonpolar covelant bond:
equal sharing between atoms, atoms have approximately the same size of nucleus
polar covalent bond
unequal sharing of electrons. creates partial postive and partial negative regions around the molecule
ionic bond
bonds formed form the electrical attraction between two oppositely charged ions
hydrogen bonding
weak electrostatic attraction between an electronegative atom and a hydrogen atom covalently linked to a second electronegative atom
hydrogen bond
-surface tension
created by hydrogen bonds. electronegative charges pull on water molecules.
-hold DNA together
-weak individually but can be strong with more than one
-can form bonds on different molecules or on itself
hydrophilic
polar, interacts with water
hydrophobic
nonpolar, doesn’t interact with water
amphipathic
have hydrophilic and hydrophobic regions
macromolecules
-nucleic acids
-proteins
-carbs
-lipids
proteins primary strucure
amino acid sequence
protein secondary structure
interaction of h bonds between the backbone of amino acids
-forms alpha helix and beta pleated sheets
protein tertiary structure
secondary structure of the same molecule that interact, gives 3d shape
-form ionic or h bonds
-stable
-hydrophobic effect
protein quaternary structure
interaction between two or more individual amino acid subunits to form a structural protein
-held by noncovalent bonds
what are the factors that affect protein ligand binding
-specificity
-affinity
-competition
-saturation
-modulation
-environment
what are the factors that affect protein ligand binding
1. specificity
how they bind in terms of shape
-influenced by shape and charges
what are the factors that affect protein ligand binding
2. affinity
how tight the bonds are
- dictated by how many hydrogen and ionic bonds are present
what are the factors that affect protein ligand binding
3. competition
may bind more than 1 particular ligand
what are the factors that affect protein ligand binding
4. saturation
caused by higher ligand numbers than proteins
-all binding sites are filled
what are the factors that affect protein ligand binding
5. modulation
can be controlled, regulation of proteins
what are the factors that affect protein ligand binding
5. modulation
-allosteric modulation
-allosteric modulation: ligand bonding in second binding site changes energy and binding affinity for the primary binding site. caused mainly from protein flexing
-activation: ligand binding to the second site causes bond energy to change which then causes the protein to flex. allows another ligand to bind to the primary binding site
-inhibition: binding at the secondary site turns off protein and does not allow binding at the primary binding site
what are the factors that affect protein ligand binding
5. modulation
-covalent modulation
-covalent modulation: uses covalent bonds from phosphorylation at the second site, which flexes and changes shape.
-activation: phosphorylation allows protein to bind to indicated ligand at primary site. removing the phosphate would cause the protein to return to its initial shape and cannot bind at its primary site
-inhibition: phosphorylation changes shape to turn protein off, changes primary site. removing the phosphate returns the protein to its initial shape and can bind to ligand
what are the factors that affect protein ligand binding
6. environment
temp:
-low temp: protein ligand binding interaction is low, little movement.
-high temp: many interactions between protein and ligands. proteins have optimum temperatures to avoid denaturing.
ph:
-increasing ph: basic solution with an access of OH-, which often interactions with electrostatic attraction between oppositely charged ions, causing denaturation
-low ph: have an access of H, acids interrupt and interact with charges and denature a protein
-have optimum ph
membrane
tissues that line a cavity
