Amino Acids: Derivatives and Chemical Modifications Flashcards
What is an axon?
Output from neuron.
What is dendrite?
The input of a neuron.
What is a neurotransmitter?
Compounds which travel across the “synaptic cleft” between neurons.
Precise: from axon of the presynaptic neuron to the dendrite of the postsynaptic neuron.
Example, dopamine.
What is a disulfide bridge?
A covalent bond.
It is a chain modification of Amino Acids.
Can occur within one polypeptide chain and also between 2 different polypeptide chains.
Cystine tho amino acid with the S group!
What is “Protein Kinase”?
It attaches phosphoryl groups to specific Ser, Thr, and Tyr side chains.
What are “Protein phosphates”?
They remove phosphoryl groups.
How does the phosphorylation of a protein affect it?
May change the properties of the protein.
What is the key mechanism of phosphorylation?
Allows cells to respond to external stimuli.
What is Glycosylation?
A very common type of modification of side chains on the protein surface.
When one or more sugars attach to one or more specific protein residues.
What is glycosylated in eukaryotic organisms?
Almost all secreted and membrane-associated proteins.
What function helps form the extracellular matrix(ECM)? What is the ECM?
Glycosylation.
ECM is a mixture or proteins and oligosaccharides between cells.
ECM is key for positioning cells properly.
ECM crucial for A LOT, ex: Developmental Biology, wound healing.
What are the two major types of Glycosylation?
- O-glycosylation: The oligosaccharide is attached to side chain O of a Ser, or Thr
- N-glycosylation: The oligosaccharide is attached to the side chain N of an Asn
Describe the process of Protein Glycosylation. You need to explain the antenna and core specifically.
- Attach oligosaccharide to Asn(or Amino Acid that can be glycosylated).
- Enzyme comes down and trims the glycan to a pentasaccharide core.
Note: All N-linked glycans in all eukaryotes are built up initially from this core! - More trimming occurs after that (specialized).
Make FC: Be able to look at these molecules and know what amino acid it was derived from and what was added. Also know that these are NOt incorporated into the poly peptide chains of protiens.
Make FC: Be able to look at these molecules and know what amino acid it was derived from and what was changed in the side chain. Can these be in the polypeptide chain?
