Covalent and Non-Covalent Flashcards
What is a covalent bond?
Bond formed when two atoms share a pair of elections
What is a non-covalent bond?
An attraction between positive and negative charges
How is covalent bonds shown in skeletal form?
Straight solid line
What is a glycosidic bond?
A bond coalently joined by two sugar molecules
How is non-covalent bonds shown in skeletal form
Dashed lines
What is the stucture of sugar phosphat backbone?
5’ end to 3’ end, antiparallel
What are Phosphodiester bonds?
Coavlent bond joining a hydroxyl group to a phosphate
What creates electrostatic interaction?
Attraction between opposite charges
What are the two types of electostatic interactions?
- Intermolecular interactions (between molecules)
- Intramolecular interactions (Within a molecule)
What is ionic bonding?
Electrostatic attraction between oppositely charged ions
How does ionic bonding affect the 3D structure of a protein?
- Maximising interactions between oppositely charged side chains
- Minimising interactions between similarly charged side chains
Why is DNA negatively charged?
Negative charge on each phosphate grop in the sugar-phosphate backbone
What occurs between phosphate groups in the DNA stucture
They repel each other
What is the Van der Waals distance?
DIstance at which two molecules are attracted to each other
What happens if the Van der Waals (London forces) distances reduces?
Electrons of the two molecules overlap due to replusion, causing rigid DNA structure
What is hydrogen bonding?
Interaction between H+ and electronegative atom (O or N)
What does a negative dipole O cause?
Draws shared electrons towards itself
How hydorgen bonds is bonded between Adenine and Thymine?
2
How many hydrogen bonds is between Guanine and Cytosine?
3
What does water do instead of forming bonds with non-polar molecules?
Forms hydrogen bond around the non-polar molecule
What happens in hydrophobic interaction when non polar molecules come together?
Water molecules are released
What benefit does Gd3+ (Gadolinium Cation) have for being highly paramagnetic
Great MRI constrast agent
What downside does Gd3+ (Gadolinium Cation) have
Highly toxic.
Gd3+ can replace what ion in the body?
Ca2+ (calcium) - due to similar charge density
What is DNA?
Polymer of nucleotides
What is a codon?
3 adjoining nucleotides
What is a gene?
The sequence of codons that code for a protein
What is a genome?
Complete set of DNA
What is DNA analysis?
Short tandem repeat analysis and mitochondrial DNA seqencing
What is mtDNA sequencing?
Samples with limited chromosomal DNA (e.g bone, teeth)
What is mitochondrial genome?
Maternally inherited
