Lecture 2: WHAT IS BIOCHEMISTRY? Flashcards
What things depend on biochemistry?
How cells:
- sense and respond to their environment
- make and break molecules
- access and use energy in food
What does the central dogma show?
DNA + DNA Replication
Transcription of DNA to form RNA
Translation of RNA to form proteins
What are the informational molecules?
DNA and RNA
What are the functional molecules?
RNA and proteins
What does the sequence of amino acids determine?
How the protein folds
Why is the structure of a protein important?
Because it determines the proteins function
What is the primary structure?
The sequence of amino acids
What is the secondary structure?
Alpha helices and beta sheets formed by side chain interaction
What is tertiary structure?
3D structure of secondary structure interacting. Parts further apart in molecules may be brought closer together
What is quaternary structure?
Protein structures interacting
How is tertiary structure stabilised?
By ionic bonds, hydrogen bonds, hydrophobic interaction and disulphide bridges
What are ionic bonds?
Between positively and negatively charged amino acid side chains (sometimes called salt bridges)
What are hydrogen bonds?
Between hydrogen and oxygen
What are hydrophobic interactions?
Between hydrophobic side chains of amino acids
What are disulphide bridges?
Occurs between neighbouring cysteine residues
What is the first step of making and isolating proteins?
Genes of interest are inserted into the plasmid
What happens after genes of interest are inserted into the plasmid?
Transfection into host cell
What happens after transfection into host cell?
Protein expression in host cell
What happens after protein expression in host cell?
Host organism expansion in bioreactor
What happens after host organism in bioreactor?
Protein purification
What happens after protein purification?
Soluble protein
What can we do by solving protein structures?
We can understand how molecules interact which allow the synthesis of mimic molecules which can be used
How do cells respond to the outside environment?
Using receptors on the cell surface
What does stimulation of cell surface receptors do?
Cause a relay of interactions of molecules (transduction) which ends in a cellular response to the initial stimuli
What is a dehydration reaction?
Removal of water for polymer formation
What is a hydrolysis reaction?
When water is added to break a bond
Why is breaking molecules important?
It breaks down a complex molecule into its individual components
What is the energy currency of a cell?
ATP
Where is ATP generated?
In the electron transport chain of the mitochondria
How is ATP made?
Through the oxidation of fuel molecules (mainly glucose and fats but also proteins)
What synthesises ATP?
A protein (ATP Synthase)
