AOS1 Flashcards
Biomacromolecule
Proteins are biomacromolecules;
- A large organic molecule (in organisms) and are composed of smaller subunits.
Polymer
Proteins can also be defined as a polymer.
- A polymer is a large molecule composed of a chain of repeating similar smaller molecules (monomers)
Monomers
A simple molecule with 2 or more binding sites (to form a macromolecule).
Proteome
Is more diverse than a genome.
- It is the entire complement of proteins in a cell or organism.
Amino acid subgroups:
- Amino group (2 hydrogens + a nitrogen).
- Central carbon (H - C).
- R group (changes)
- Carboxyl group (C =O - O - H)
Polymerisation of amino acids:
- The hydroxyl group is broken off the carboxyl of one amino acid to form a covalent bond with the hydrogen from the other amino group to form a water molecule.
- Amino acid residues are joined together in a peptide bond. (condensation reaction).
( 100 or more chain = poly peptide )
( 20 or less = peptide )
4 levels of protein structure
- Primary.
- Secondary.
- Tertiary.
- Quaternary.
Primary
The sequence of amino acids in a protein.
Secondary
3D form of segments of a polypeptide chain; due to the interactions between nearby amino acids including the Alpha Helices and Beta Pleated Sheets.
Tertiary
The overall 3D shape of a protein (polypeptide).
(The shape of the protein determines its function).
- Folded into shape by chaperone proteins.
- When folded it is held by a hydrogen bond or a disulfide bond between cysteine amino acids.
Quaternary
- Only occurs if the protein is made of more than 1 polypeptide chain.
- When a polypeptide joins to another biomacromolecule.
Purines:
2 nitrogen-containing carbon ring.
- Adenine.
- Guanine.
Pyrimidines:
1 nitrogen-containing carbon ring.
- Cytosine.
- Thymine.
- Urical.
Proteins
Biomacromolecule made up of amino acid chains folded into a 3D shape.
Nucleic acids:
Information molecules that encode instructions for the synthesis of proteins.
- Pentose (5 carbon) sugar.
- Nitrogenous-containing base.
- Phosphate group.
3 main forms of RNA:
- Messenger RNA.
- Transfer RNA.
- Ribosomal RNA.
Messenger RNA
(mRNA).
Carries genetic code from DNA in the nucleus to the ribosome.
Transfer RNA
Carries specific amino acids from the cytoplasm to the ribosome and pairs with complementary code carried by mRNA.
Ribosomal RNA
The main structural component of ribosomes within cells.
RNA polymerisation.
RNA built by enzyme; RNA polymerase.
- Polymerase built on a 5’-3’ direction adding new nucleotides to 3’ end.
Structure of genes:
Exons, Introns, promoter and operator regions
Introns
Contain non-coding DNA.
- Transcribed regions of eukaryotic genes that are REMOVED from RNA before translation.
(Occurs in RNA processing).
- Not found in prokaryotic
Exons
Are EXPRESSED
- Transcribed regions of a gene that are translated.
- Coding DNA.
5’ UTR (untranslated region).
3’ UTR
“the leader”
- upstream; front of gene.
“the trailer”
- downstream.