Lecture notes

Molecular Genetics

0 purchase

Module
Biomedical Sciences

Institution
University Of Chester (UoC)

A brief but heavily detailed document containing the core subjects in molecular genetics, including key words and their meanings. This will give you a good understanding of molecular genetics at a second year biomedical science level, without having to take in too much information about each indivi...

[Show more]

Preview 2 out of 12 pages

View example

Uploaded on December 16, 2021
Number of pages 12
Written in 2020/2021
Type Lecture notes
Professor(s) Laurence seabra
Contains Molecular genetics

molecular
genetics
molecules
molecular genetics
primary structure
secondary structure
tertiary structure
 quaternary structure
chromatography
gas phase
ion phase
blotting techniques
western blotting

£5.49

Add to cart

Save

100% satisfaction guarantee
Immediately available after payment
Both online and in PDF
No strings attached

Molecular genetics

03/10/2019

 Denaturation – disruption of bonds and structures in DNA and protein e.g. turning liquid gelatine
into solid jelly. Caused by environment alterations like pH, salt, temp).
 Renaturation – Proteins return to normal when normal environment is set
 Structure of protein dictates function, and amino acid order determines conformation of
protein.
 Monomers are amino acids; proteins are the polymers.
 Amino acids contain amino group, carboxyl group, hydrogen atom, variable R group (side chain)
 PRIMARY STRUCTURE
 R chains differentiate 20 different amino acids – 4 categories are polar (hydrophobic), non-polar
(hydrophilic), acidic, and basic.
 Nonpolar (glycine, proline), polar (serine, tyrosine, glutamine),
 Acidic (carboxyl acid, negative charge) and basic (hydrogen, positively charged) are electrically
charged
 Amino acids exist as stereoisomers (L or D mirror image forms)
 mammalian proteins made of L-isomers
 Residue or moiety – component amino acid in a polypeptide chain
 1⁴ can mean the 4th amino acid etc. etc. with any other number.
 Carboxyl group and amine cause condensation reaction
 Peptides – links between amino acids.
 SECONDARY STRUCTURE
 Alpha helix (tight coiled polypeptide backbone core)
 Beta pleated sheet formed when two or more polypeptides come side by side
 TERTIERY STRUCTURE
 3-D conformation. Reveals about function and evolution.
 R groups and R groups interact, and R groups and backbones.
 Bonds: hydrogen , ionic, covalent (disulphide bridges), hydrophobic (interior of protein)
 Proline’s R group connects to amino group and forms natural kink in polypeptide. Tertiary
structure, good for making drugs and vaccines.
 X-ray crystallographic studies last years, nuclear magnetic resonance is shorter.
 QUATERNARY STRUCTURE
 4 tertiary structures coming together (e.g. insulin)
 Forms globular and fibrous proteins. not in all proteins.
 Globular – water soluble, compact
 People with anaemia can struggle with these structures
 Fibrous – water insoluble e.g. collagen
 Protein binding examples : antibodies, enzymes, neurotransmitters
 Protein folding occurs spontaneously and are aided by chaperone proteins (chaperonins),
providing ideal environment for folding.
 Conformational change – change in shape once bound to something

 Structural layers in the formation of a protein – primary, secondary, tertiary, quaternary
structures. All build up from amino acids in a condensation reaction to form peptide bonds. Each
amino acid could be polar, nonpolar, acidic, or basic in their R groups. Alpha helices and beta

, pleated sheets join in secondary structure. Tertiary 3-D structure are secondary structures joined
by covalent bonds (disulphide bridges), ionic bonds, hydrophobic bonds (interior), and hydrogen
bonds.

10/10/2019

 Mobile phase – liquid or gas, a transporter
 Stationary phase – impedes different components of the solution to different degrees
 Ion exchange chromatography is separation based on charge. Charged molecules are large
proteins, small nucleotides, amino acids. Relies on charge-charge interactions between the
proteins, the two types are: anion exchangers, cation exchangers
 Ions – the same charged molecules
 Cation exchange chromatography – positively charged molecules are attracted to a
negatively charged solid support. Commonly used resins are: S-resin, sulphonyl group
derivatives,
 Anion exchange chromatography – negatively charged molecules are attached to a positively
charged solid support. Common resins are: Q-resin, a quaternary amine.
 Oligonucleotide – a big stretch of DNA
 Disadvantages of gel flowmetry – proteolysis (the breakdown of proteins) occurs , large size
columns mean large volumes of eluent and higher cost, non-ideal flow around beads
 HIS (X6), GST, FLAG TAGs are all specific unique sequences that do not exist in any human
genomes but, when attached to a protein, it allows us to see where the protein is going.
 Epitope – short sequence of peptides
 Polyclonal antibodies – derived from B cell clones; recognises only a single epitope on an
antigen.
 Affinity chromatography has 3 components; matrix, ligands, spacer or covalent link. Has the
highest costs due to the components being so expensive i.e. antibodies cost lots.

17/10/2019

 Restriction enzymes – cleaves certain DNA sequences at a particular point.
 Dyes to stain DNA will bind to the specific DNA sequences in order to find certain genetic
makeup.
 Southern blotting (DNA) – Detection of DNA molecules with transfer. DNA is cut using Res ->
DNA is denatured -> needs to be separated onto an agarose gel or polyacrylamide gel ->
transferred onto a solid support etc. Uses UV light for detection.
 Northern blotting (RNA)– Detection of RNA (transcript) molecules for blotting and probing.
RNA extracted from cells fractionated on an agarose gel -> transferred to a nylon (or similar)
membrane -> hybridized to a solution of a radiolabelled cDNA probe corresponding to the
mRNA of interest. Measurement in base pairs.
 Western blotting (Proteins) – Detecting proteins following transfer to membranes after
polyacrylamide gel electrophoresis. Proteins extracted through cell lysis, and the proteins
are denatured. Blocking is used to avoid membrane cross-reactions.
 KDAs – kilodalton (atomic mass unit)

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller kaitlynjh1. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £5.49. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

77071 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 15 years now

Start selling