Bio and Chem Flashcards
What are selectins?
Bind to carbohydrate molecules that project from other cell surfaces
Repetitive DNA
Found near centromeres of chromosomes. May contain genes that are transcribed and translated. Higher mutation rate than single copy DNA
Function of Motor proteins?
Display enzymatic activity by acting as ATPases that power the conformational change necessary for motor function
What are selectins, integrins, and cadherins categorized as?
Cell Adhesion Molecules (CAMs)
What are Integrins?
A group of proteins that all have two membrane-spanning chains called Alpha and Beta that bind to and communicate with the extracellular matrix
Small Nuclear RNA (snRNA)
- Primary function is in processing of pre-mRNA in the nucleus. They also aid in regulation of transcription factors or RNA polymerase II, and maintaining telomeres.
- can be associated with a specific set of proteins that form complexes called snRNPs
- There’s a special snRNP complex called spliceosome (snRNA + snRNP = spliceosome), which removes introns during processing of pre-mRNA. Spliceosomes work by binding to ends of an intron and performing two sequential trans-esterification reactions that splice out introns and ligate exons to form mature mRNA.
Micro RNA (miRNA)
- functions in transcriptional and post-transcriptional regulation of gene expression by base pairing with complementary sequences within mRNA molecules
• This usually results in gene silencing. The mRNAs to which miRNAs bind are prevented from translation or sent through a pathway for degradation.
Cofactors
Participate directly in catalysis usually by stabilizing the substrate along with the enzyme (ex. DNA Polymerase)
What are Cadherins?
A group of glycoproteins that mediate calcium-dependent cell adhesion
Single-copy Genes
Holds the organism’s most important genetic information and those that are actively transcribed
Highly Repetitive DNA
Contain no genes. Not transcribed or translated.
Transfer RNA (tRNA)
links codons in mRNA strand to corresponding amino acid for polypeptides
Small Nucleolar RNA (snoRNA)
class of small RNA molecules that guide covalent modifications of rRNA, tRNA, and snRNA through methylation or pseudouridylation (addition of an isomer of nucleotide uridine). Also relevant during translation
Non-Coding RNAs
functional RNA molecule that is not translated into a protein. It performs vital functions in the cell still as RNA
Solvation Layer
describes the structured organization of a solvent (e.g. water) around a solute (e.g. a polypeptide or protein). In the case of a protein which displays hydrophobic residues on its surface, the surrounding water will orient into a highly structured organization to optimize hydrogen bonding among water molecules (as hydrogen bonding with the presented hydrophobic side chains is not an option). This highly ordered rearrangement has a much lower entropy and is less favorable than if polar side chains were present on the surface of the protein. Thus, a conformation that buries its hydrophobic residues inside the protein leads to less disruption of water’s hydrogen bonding, allowing for less structure and higher entropy, which increases the protein’s conformational stability.
Ionization Energy (Potential)
With less electronegativity, there is also less ionization energy. This means for metals, it is easier to lose the electrons. When it is easier to lose the electrons, the metal becomes more reactive because it uses less energy to fulfill its goal; to gain a full outer shell.
