New biophysics Flashcards
What are eukaryotic cells?
Cells with a nucleus that contains genetic material (DNA) (like animals, plants, fungi, protozoa and algae). Can be uni- or multi-cellular
What are prokaryotic cells?
Cells without a nucleus (like bacteria). Always uni-cellular
What are organelles?
Organelles are compartments within a cell with specific specialised functions. They can be membrane bound or membraneless. Each organelle can have completely different protein and ion compositions to those surrounding it.
What are organelle examples?
nuclear membrane, the Golgi Apparatus, the Endoplasmic Reticulum and the Mitochondria
What are structural features of the cell made of and what are examples of them?
The structural features of the cell can be made by lipids or proteins. Outside part of the cell is the plasma membrane (made of lipids) and microtubules and actin filaments are structural features made from proteins.
What is the genome?
entire set of DNA of an organism
What is a polypeptide chain?
A protein
What shape are viruses?
Icosahedra
What can viruses have to make them more complicated?
Lipid bilayers and surface receptors
What is a codon and what does it do?
3 nucleotides and it tells us what amino acid is going to be produced
How many amino acids are there?
20, plus start and stop codons
What is gene expression?
process by which DNA instructions convert into proteins with two key stages: transcription and translation
What are the 4 types of protein structure?
Primary, secondary, tertiary and quaternary
What is the most common type of protein structure?
Tertiary
What is roughly the volume for one base pair?
1 cubic nanometre
The volume of a container (eg a nucleus) is measured in what amounts usually?
Cubic nanometres
What is the Levinthal paradox?
The correct protein folding by a simple random search is very improbable and would take a long time and yet correctly folded proteins are common and happen relatively quickly
What is the solution to the Levinthal paradox?
Folding is not random and protein sequences contain folding pathway information.
How is the helix shape made in alpha helices?
They have a hydrogen bond every 4th amino acid connected to each other (so there’s 2 amino acids between the connected ones)
What is Gibbs free energy?
maximum reversible work that may be performed by a system at constant temperature and pressure
What is enthalpy (H)?
heat absorbed or released
What is entropy (S)?
measure of disorder in a system
What is the hydrophobic effect when considering protein folding?
causes hydrophobic residues to hide in the centre and hydrophilic residues to be pushed outwards
What does the spontaneous back-to back arrangement of a bilayer of lipids for the cell membrane look like?
The hydrophilic head groups on the outside in water (which is where they self-assemble) and the hydrophobic tails in the core of the membrane