Intro to Cell/ Biochemistry
Without energy input an isolated system will move to disorder.
What is Second Law of Thermodynamics?
Characteristic of secondary structures that allows proteins to interface with both hydrophobic and hydrophilic environments
What is amphiphilic properties?
Binding to this site on an enzyme can change the shape of the active site.
What is an allosteric site? (Competitive inhibitors bind the active site not the allosteric site)
These proteins are the main components around which eukaryotic DNA is wrapped to form nucleosomes.
What are histones?
A phospholipid has a hydrophilic head and hydrophobic tails. A term used to describe molecules which contain both hydrophilic and hydrophobic regions.
What is amphipathic?
Bond formed from a condensation reaction between the carboxyl group of one amino acid with the amino group of the adjacent amino acid.
What is peptide bond?
Agreement in the binding of two ligands to a specific conformation
What is cooperative binding?
Eukaryotes wrap DNA tightly around histones into nucleosomes forming this form of DNA
What is chromatin?
(The phosphate backbone is - charged, histones are + charged, these bind together to form the nucleosomes)
This interaction occurs when oppositely charged atoms or molecules attract each other and helps stabilize biological molecules.
What is an ionic interaction?
Two cysteine side chains are oxidized creating a covalent bond that helps stabilize a proteins folded structure.
What is a disulfide bond?
Regulatory enzyme found as a single protein or as a protein complex with interchangeable parts diversifying it's functionality
What is ubiquitin ligase?
The three specialized nucleotide sequences on the chromosomal DNA molecule required for replication
What are replication origin, centromere, and telomere?
This type of reaction joins monomers, removes water, and requires energy.
What is dehydration synthesis? (Condensation, an -OH group and a H are removed (H2O), -the opposite of this reaction is hydrolysis)
This level of protein structure describes the overall three-dimensional shape of a single polypeptide and is stabilized by interactions between amino acid side chains.
What is tertiary structure?
Inhibitors compete with substrates for binding at an enzymes active site. If you increase the substrate concentration you can overcome the inhibitory effect. Vmax remains unaffected but apparent Km increases.
What is competitive inhibition?
Spreading of heterochromatic state into a region of euchromatic DNA
What is position effect variegation?
Base pairing between these two ensures the width of the DNA double-stranded helix is constant
What is a (double-ring) purine and (single-ring) pyrimidine?
A region in a protein that changes shape to turn a biological process on or off. (Hint: GTP-binding proteins like Ras use this mechanism.)
What is a molecular switch?
(If GTP is bound Ras is active, If GDP is bound Ras is inactive)
This type of protein regulation occurs when a molecule binds to a site separate from the active site and changes the protein's conformation, increasing or decreasing its activity.
What is allosteric regulation?
Acetyl groups are added to lysine residues in histone tails thereby neutralizing their positive charge. Chromatin becomes more accessible for transcription.
What is histone acetylation?