Unit 4: Translation And Protein Structure Flashcards
Alpha Carbon
The central carbon atom of an amino acid
Amino Group
NH2
Carboxyl Group
COOH
Side Chain/R Group
Differs from one amino acid to the next and makes the amino acid unique
Peptide Bond
The bond formed between two amino acids
Carboxyl End
One end of a peptide that has a free carboxyl group
Polypeptide
A polymer of amino acids connected by peptide bonds
Protein
A polypeptide chain that has folded into a stable three-dimensional confirmation
Residues
Amino acids that are incorporated into a protein
Primary Structure
The sequence of amino acids in a protein
Secondary Structures
Interactions between stretches of amino acids in a protein
Tertiary Structure
Longer range interactions between secondary structures that support three-dimensional shape of the protein
Quaternary Structure
The interactions of several individual polypeptides
Alpha Helix
The polypeptide backbone that is totally twisted in a a right handed coil with 3.6 amino acids per turn, stabilized by hydrogen bonds between the carbonyl and amide groups
Beta Sheet
A polypeptide that folds back and forth on itself, forming a sheet that is stabilized by hydrogen bonds between carbonyl groups in one chain and amide groups in the other chain.
Denatured
Proteins that lose their functional activity
Chaperons
Evolved proteins in cells that help protect slow-folding or denatured proteins until they can attain their proper three-dimensional structure
Transcription
The sequence of base pairs along part of a DNA strand is used as a template in the synthesis of a complementary sequence of bases in a molecule of RNA.
Translation
The sequence of bases in an RNA molecule known as mRNA is used to specify the order in which successive amino acids are added to a newly synthesized polypeptide chain
Messenger RNA (mRNA)
The RNA molecule that combines with a ribosome to direct protein synthesis
Ribosomes
Complex structures of RNA and protein
Transfer RNA (tRNA)
Noncoding RNA that carries individual amino acids for use in translation
A (Aminoacyl Site)
One of three binding sites for tRNA on the large subunit of a ribosome
P (Peptidyl) Site
One of three binding sites for tRNA on the large subunit of a ribosome
E (Exit) Site
One of three binding sites for tRNA on the large subunit of a ribosome
Codon
Codes for a single amino acid in the polypeptide chain
Reading Frames
A consecutive sequence of codons for amino acids
Aminoacyl tRNA Synthetases
Connect specific amino acids to specific tRNA molecules
Genetic Code
The correspondence between codons and amino acids, in which 20 amino acids are specified by 64 codons
Initiation
The initiator AUG codon is recognized and Met is established as the first amino acid in the new polypeptide chain
Elongation
Successive amino acids are added one by one to the growing chain
Termination
The addition of amino acids stops and the completed polypeptide chain is released from the ribosome
Initiation Factors
Proteins that bind to mRNA that initiate translation
Elongation Factors
Proteins that break the high-energy bonds of the molecule GTP that help in ribosome movement
Release Factor
A protein that binds to the A site of the ribosome, causing the bond connecting the polypeptide to the tRNA to break, which completes the chain.
Polycistronic mRNA
mRNA in prokaryotes that contains open reading frames for one then one protein.
Operon
A type of gene organization in which functionally related genes are located in tandem along the DNA and transcribed as a single unit from one promoter
Protein Families
Proteins that are structurally and functionally related
Folding Domain
A region of a protein that folds in a similar way relatively independently of the rest of the protein
Mutation
A change in the sequence of a gene
Selection
Random mutations that are retained or eliminated among individuals based on their ability to survive and reproduce
