DNA TRANSLATION

Proteins that move molecules across cell membranes.

Proteins that provide support and shape to organisms.

Proteins that enable muscle movement.

Proteins that are part of the immune system.

The most diverse protein group; they speed up reactions.

A central carbon atom bonded to a carboxyl group, an amino group, a hydrogen atom, and a side chain (R group) that varies between amino acids.

The R group (side chain) of each amino acid determines its unique properties, including whether it is nonpolar (hydrophobic), polar (hydrophilic), or charged.

A covalent bond formed between the carboxyl group of one amino acid and the amino group of another amino acid, releasing a water molecule.

All polypeptide chains have an N-terminus (with a free amino group) at one end and a C-terminus (with a free carboxyl group) at the other.

Some amino acids can be chemically modified after protein synthesis, creating new amino acids with unique properties.

The set of rules that translates a sequence of DNA or RNA nucleotides into a sequence of amino acids during protein synthesis.

A three-nucleotide sequence within mRNA that specifies a particular amino acid or a stop signal during protein synthesis.

The way in which nucleotides are grouped into codons during translation, determining the sequence of amino acids in a polypeptide.

The genetic code is almost identical in all living organisms, meaning that the same codons specify the same amino acids across different species.

Genes can be moved from one species to another and still be correctly transcribed and translated because of the universality of the genetic code.

The first codon in a messenger RNA (mRNA) sequence that initiates translation, signaling the ribosome to start protein synthesis. In all organisms, the start codon is AUG, which codes for the amino acid methionine.

A three-nucleotide sequence in mRNA that signals the end of translation. Stop codons do not code for any amino acid, but instead tell the ribosome to stop adding amino acids to the growing polypeptide chain. There are three stop codons: UAA, UAG, and UGA.

The genetic code is redundant because multiple codons can specify the same amino acid. This means that a single amino acid can be coded for by more than one triplet sequence of nucleotides.

Another term for 'redundant genetic code', meaning that a single amino acid may be specified by more than one codon.

Each codon specifies only one amino acid. It's a one-to-one relationship between a three-nucleotide codon and its corresponding amino acid.

There are three stop codons: UAA, UAG, and UGA. They don't code for amino acids, but signal the end of protein synthesis.

A single base change in a codon, altering the DNA sequence.

A point mutation that doesn't change the amino acid specified by the codon.

A point mutation that changes the amino acid specified by the codon.

A point mutation that changes an amino acid codon into a stop codon, terminating protein synthesis early.

A nonsense mutation often leads to a nonfunctional protein because it truncates (shortens) the protein before it's complete, making the protein unable to carry out its normal function.

A mutation caused by insertion or deletion of nucleotides, altering the reading frame of codons and changing the amino acid sequence from the point of the mutation.

A mutation resulting from the insertion or deletion of one or more nucleotide pairs within a gene.

InDel mutations can dramatically alter the reading frame and amino acid sequence, usually leading to a non-functional protein.

InDel mutations can drastically alter the reading frame and amino acid sequence, leading to a non-functional protein.

Frameshift mutations often result in a non-functional protein due to a shift in the reading frame and subsequent incorrect amino acid sequence.

Translation is the process of converting the genetic code carried by mRNA into a chain of amino acids, forming a protein.

A codon is a three-nucleotide sequence within mRNA that specifies a particular amino acid or a stop signal during protein synthesis.

Translation requires amino acids, mRNA, tRNA, ribosomes, and enzymes.

Translation involves three main steps: initiation, elongation, and termination.

The start codon is AUG, which codes for the amino acid methionine and signals the ribosome to begin protein synthesis.

tRNA has a cloverleaf structure with four stems: anticodon, amino acid acceptor, T stem & D stem. This shape is maintained by hydrogen bonds between complementary bases.

tRNA molecules act as adapters, carrying specific amino acids to the ribosome where they are added to the growing polypeptide chain according to the mRNA sequence.

The anticodon loop of a tRNA molecule contains a three-nucleotide sequence that is complementary and antiparallel to a specific mRNA codon, ensuring the correct amino acid is added to the growing polypeptide chain.

Each tRNA molecule carries a specific amino acid attached to its 3' end, specifically at the CCA sequence, via a covalent bond. The amino acid is determined by the tRNA's anticodon.

tRNA plays a crucial role in protein synthesis by delivering the correct amino acid to the ribosome based on the mRNA sequence, allowing for the creation of the protein.

The process of attaching a specific amino acid to its corresponding tRNA molecule.

An enzyme responsible for catalyzing the attachment of a specific amino acid to its corresponding tRNA molecule during aminoacylation.

Aminoacylation occurs at the 3' end of tRNA, specifically at the CCA sequence.

Aminoacylation is crucial for protein synthesis because it ensures that the correct amino acids are delivered to the ribosome based on the mRNA sequence.

Each aminoacyl tRNA synthetase recognizes and binds to only one specific type of amino acid. This ensures that the correct amino acid is attached to its corresponding tRNA.

The first two mRNA codon bases pair strictly with tRNA anticodon bases, but the third base can pair loosely, allowing some flexibility in the genetic code.

The third base in a mRNA codon is less spatially constrained, allowing it to form less strict base pairs with the tRNA anticodon.

A modified tRNA base that can pair with adenine (A), cytosine (C), or uracil (U) at the wobble position, expanding the flexibility of the genetic code.

The wobble hypothesis explains why the genetic code is flexible, meaning multiple codons can specify the same amino acid. This is due to the less strict base pairing rules at the third codon position.

A non-standard base pairing between the third mRNA codon base and the first tRNA anticodon base, contributing to the flexibility of the genetic code.

Ribosomes are essential for protein synthesis, translating the genetic code carried by messenger RNA (mRNA) into a chain of amino acids, forming a protein.

Ribosomes are composed of two subunits: a large subunit and a small subunit. Each subunit consists of ribosomal proteins and ribosomal RNA (rRNA).

Prokaryotic ribosomes have a 70S sedimentation coefficient (50S + 30S), while eukaryotic ribosomes have an 80S sedimentation coefficient (60S + 40S).

The A site (aminoacyl site) on a ribosome is where tRNA molecules carrying amino acids arrive, ready to be added to the growing polypeptide chain.

The P site (peptidyl site) on a ribosome is where the peptide bond is formed between the newly arrived amino acid and the growing polypeptide chain.

A short sequence in mRNA (AGGAGG) recognized by the 16S rRNA in the 30S ribosome subunit, facilitating mRNA binding and initiation of translation in bacteria.

A protein that binds to the A site of the 30S ribosome subunit in bacteria, preventing premature entry of tRNA.

A protein that binds to the 30S ribosome subunit, preventing premature binding of the 50S subunit and facilitating mRNA binding.

A protein that binds to fMet-tRNA and helps it deliver to the 30S subunit in bacteria, along with GTP.

The complete assembly of the 30S subunit, mRNA, fMet-tRNA and the 50S subunit, ready for protein synthesis.

The Kozak sequence is a specific sequence in eukaryotic mRNA (5'-GCCRCCAUGG-3') that helps align the mRNA with the small ribosomal subunit (40S) for translation initiation. It acts as a signal for the ribosome to identify the start codon (AUG) and begin protein synthesis.

eIF2 (eukaryotic initiation factor 2) is a protein that binds to the initiator methionine tRNA (Met-tRNA) and guides it to the start codon (AUG) in the P site of the ribosome. It also helps with GTP hydrolysis, a process required for initiation complex formation.

After the mRNA binds to the 40S subunit and the initiator tRNA (Met-tRNA) binds to the start codon, the 60S subunit joins the complex, creating a functional ribosome ready for protein synthesis.

eIF1 (eukaryotic initiation factor 1) helps to form the initiation complex by preventing premature binding of tRNA to the A site of the ribosome. It also promotes dissociation of the small ribosomal subunit (40S) from the large subunit (60S) after translation termination.

eIF3 (eukaryotic initiation factor 3) is a protein that binds to the 40S ribosomal subunit and helps to recruit mRNA. It also contributes to the dissociation of the 80S ribosome into its subunits during translation termination.

In prokaryotes, the initiator tRNA (fMet-tRNA) binds to the P site of the ribosome. In eukaryotes, the initiator tRNA (Met-tRNA) also binds to the P site, but the start codon is preceded by a Kozak sequence. Both use different initiation factors.

After the peptide bond is formed between the amino acid in the A site and the growing polypeptide chain in the P site, the ribosome shifts one codon position to the left. The tRNA in the A site moves to the P site, and the empty tRNA in the P site moves to the E site and exits the ribosome.

Peptidyl transferases are a type of ribozyme found in both prokaryotes and eukaryotes that catalyze the formation of peptide bonds between amino acids during translation. They are part of the large ribosomal subunit and transfer the growing peptide chain to the tRNA in the A site.

Elongation factors are proteins that play essential roles in the elongation phase of translation. They help to recruit charged tRNAs to the A site, facilitate peptide bond formation, and promote the translocation of the ribosome along the mRNA. Specific elongation factors exist in prokaryotes and eukaryotes.

23S rRNA in prokaryotes and 28S rRNA in eukaryotes are found in the large ribosomal subunit. They act as ribozymes called peptidyl transferases, catalyzing peptide bond formation between amino acids in the ribosome during translation.

The final stage of protein synthesis where the ribosome reaches a stop codon on the mRNA, halting the addition of amino acids and releasing the newly formed polypeptide.

Proteins that bind to the ribosome when it encounters a stop codon. They stimulate the release of the polypeptide from the tRNA and the disassociation of ribosomal subunits.

Release factors require GTP (guanosine triphosphate) for their activity, just like many other proteins involved in cellular processes. GTP hydrolysis provides the energy for the release process.

The process of breaking the bond between the last amino acid in the polypeptide chain and the tRNA, releasing the finished polypeptide from the ribosome during termination.

A group of ribosomes simultaneously translating the same mRNA molecule, allowing for the rapid production of many identical protein molecules.

The presence of polyribosomes suggests that a cell is actively producing a particular protein because multiple ribosomes translating the same mRNA molecule means a large amount of the protein product is being made.

As a ribosome moves along an mRNA molecule during translation, it leaves the mRNA free to associate with another ribosome, allowing multiple ribosomes to translate the same mRNA simultaneously.

After a ribosome has moved along a segment of mRNA, the mRNA becomes available for another ribosome to attach and start translation, facilitating the efficient production of multiple protein molecules.

Polyribosomes enable cells to produce large quantities of a specific protein quickly and efficiently, meeting the cell's demand for that particular protein.

The first amino acid in a protein can be removed or modified after translation. This can change the protein's function.

Individual amino acid residues in a protein can be chemically modified after translation. This can alter the protein's structure, stability, or activity.

Carbohydrate chains can be added to proteins after translation. These are called glycosylation and can affect protein folding, stability, and signaling.

Parts of a polypeptide chain can be removed after translation. This creates a functional protein by removing unnecessary or potentially harmful segments.

Proteins can bind to metal ions, forming a complex that is essential for the protein's function.