1.2: Proteins Flashcards
The entire set of proteins expressed by the genome of an organism.
Proteome
Process that results in many different proteins being synthesised from each gene which may explain why the proteins is much larger than the genome.
Alternative RNA splicing
Various exons of a gene may be included or excluded from the final. mature mRNA.
Alternative RNA splicing
Coding DNA and RNA
AND
Non-coding DNA and RNA.
Exon
AND
Intron
Products of non-coding RNA genes.
Transfer RNA (tRNA) or Ribosomal RNA (rRNA) or RNA that controls expression of other genes
Internal and external factors
that affect the set of proteins
size on the surface area to
expressed by a cell.
Metabolic activity OR Cellular stress OR Signalling molecules OR Disease
Affect of an increase in cell size on the surface area to volume ratio.
Decreases
Network of tubules continuous with the nuclear membrane involved in lipid and protein synthesis.
Endoplasmic reticulum or ER
The sequence in which the amino acids are synthesised into the polypeptide.
Primary protein structure
Series of flattened membrane discs involved in protein modification and secretion.
Golgi apparatus
Vesicles containing hydrolase
enzymes used to digest worn
out organelles and invading
micro-organisms.
Lysosomes
Membrane containers that transport materials around the cell using protein motors and microtubules.
Vesicles
Protein fibres that carry vesicles to the correct destination.
Microtubules
Organelle that synthesises lipids such as phospholipids.
Smooth Endoplasmic reticulum or SER
Translates mRNA to produce proteins.
Ribosomes
Part of cell all proteins start to be translated by ribosomes.
Cytosol
Short stretch of amino acids at the start of a protein that determines the eventual site for complete translation.
Signal sequence
Two parts of a cell involved in the complete synthesises of a transmembrane protein.
Cytosol and Rough ER
Part of RER in which the translation of transmembrane proteins are completed.
Membrane
Part of RER in which the translation of proteins to be secreted are completed.
Lumen
Examples of secreted proteins
Peptide hormones OR Digestive enzymes
Process in which sugars are added to proteins as they pass though the Golgi apparatus.
Post-translational modification
Term for a short section of an inactive precursor enzyme being cut out to activate once secreted into the digestive system.
Proteolytic cleavage
Structural changes which may result in several different forms of the same protein.
Post-translational modification
Change in the shape of a protein which usually results in a change in function or activity.
Conformation change
Polymer composed of many amino acid monomers
Protein
Describes the structure and function of a protein.
Sequence of amino acid’s
Covalent bond joining amino acids in a polypeptide.
Peptide bond
The sequence in which the amino acids are synthesised into the polypeptide.
Peptide bond
Bonds that hold the secondary protein structure together.
Hydrogen
The sequence in which the amino acids are synthesised into the polypeptide.
Primary protein structure
Types of secondary protein structures.
Alpha helixes AND Parallel / anti-parallel beta pleated sheets AND Turns.
Classes of amino acid R groups.
Basic (positively charged), Acidic (negatively charged), Polar and Hydrophobic.
Level of protein structure which is folded and held together by various bonds and interactions between the R groups.
Tertiary
Types of bonds and interactions that hold a folded tertiary protein structure together
Ionic bonds, hydrogen bonds, ldfs, disulphide bridges or hydrophobic interactions.
A non-protein unit which is tightly bound to a protein and is necessary for its function.
Prosthetic group.
What level of protein structure is haemoglobin? It is also the protein structure of an allosteric protein that consists of four subunits.
Quaternary structure
Factors influencing interactions between R groups.
Temperature and pH
Substance that can bind to the protein R groups which are not involved in protein folding.
Ligand
Region of protein with complementary shape and chemistry to a ligand.
Binding site
Consequence of the conformation change once a ligand binds to a protein.
Change of function OR protein activated OR protein deactivated
Proteins that have at least two active sites which are spatially separate.
Allosteric
Term for changes in binding at one subunit alters the affinity of the remaining subunits in allosteric proteins.
Co-operativity
Name for the second binding site on allosteric enzymes.
Allosteric or secondary
Name for molecules that regulate the activity of an enzyme when they bind to an allosteric site.
Modulators
Ligand that binds to a secondary allosteric binding Site increasing the affinity of the enzyme for the substrate.
Positive modulator
Ligand that binds to a
secondary allosteric binding site decreasing the activity of the enzyme.
Negative modulator
Term for the strength of attraction between a protein and its ligand.
Affinity
Quaternary protein found in red blood cells which shows co-operativity in the binding of oxygen.
Haemoglobin
Affect of the first oxygen binding to a haemoglobin subunit on the affinity to the second due to co-operativity.
Increased
Factors which decrease the affinity of haemoglobin for oxygen. Causes a right shift in oxygen dissociation curves.
Increased temperature AND decreased pH
Form of post translational modification where a phosphate group is added to a protein, resulting in a reversible conformation change.
Phosphorylation
Enzyme which adds a phosphate group to protein molecules (phosphorylation).
Protein kinase
Source of the phosphate protein kinase adds to proteins.
ATP
Enzyme which removes a phosphate group from protein molecules (dephosphorylation).
Protein phosphorylase
Affect of phosphorylation on proteins.
Change in conformation or activity.
Examples of cellular proteins who activity is regulated by phosphorylation or dephosphorylation.
Enzymes or receptors.
Charges added to protein by phosphorylation.
Negative
