Biology Chapter on Biomolecules and Transcription

A molecule that stores the genetic information of an organism, encoding for proteins. It is a double-stranded helix made up of nucleotides.

A molecule that carries the instructions for protein synthesis from DNA to the ribosomes. It is a single-stranded molecule made up of nucleotides.

The fundamental principle of molecular biology that describes the flow of genetic information from DNA to RNA to protein.

The process of converting genetic information encoded in DNA into a functional product, typically a protein.

The process of copying genetic information from DNA into RNA. It occurs in the nucleus of the cell.

The process of using RNA to build a protein. It occurs in the ribosomes of the cell.

A type of RNA that carries instructions for protein synthesis from DNA to ribosomes. It is a messenger molecule.

A type of RNA that links mRNA code to amino acids during protein synthesis. It acts as a connector.

A molecule with uneven distribution of charge, creating slightly positive and negative regions.

An attraction between the slightly positive hydrogen of one water molecule and the slightly negative oxygen of another.

Substances that attract water and dissolve in it, like sugar or salt.

Substances that repel water and don't dissolve in it, like oil.

Carbon forms the backbone of organic molecules, creating diverse chains, rings, and branched structures by bonding with hydrogen, oxygen, and nitrogen.

The first step in transcription where RNA polymerase binds to the DNA template at the promoter region, initiating the synthesis of RNA.

Proteins that bind to the promoter region and help RNA polymerase initiate transcription in eukaryotes.

Proteins that bind to enhancer sequences, which are DNA regions that boost transcription of the gene.

The region of DNA that is unwound during transcription, allowing RNA polymerase access to the template strand.

A protective structure added to the beginning of a newly transcribed RNA molecule in eukaryotes.

A string of adenine nucleotides added to the end of a newly transcribed RNA molecule in eukaryotes.

The process of removing introns (non-coding sequences) from a primary RNA transcript in eukaryotes.

The stage of transcription where RNA polymerase moves along the DNA template, adding complementary RNA nucleotides to the growing RNA chain.

Sigma factors are proteins that bind to RNA polymerase, enabling it to recognize and attach to specific promoter regions on DNA, initiating the transcription process.

RNA polymerase is an enzyme responsible for building RNA molecules using DNA as a template. It separates DNA strands, creates a hybrid RNA-DNA structure, and releases the newly synthesized RNA molecule.

In prokaryotes, transcription and translation occur simultaneously in the cytoplasm. This is possible because there is no nuclear envelope to separate these processes.

The primary transcript in prokaryotes is mRNA, directly translated into protein. It can also contain information for multiple genes, leading to polycistronic mRNA.

A single mRNA molecule that carries information for multiple genes. This is common in prokaryotes and allows them to efficiently express several genes at once.

Organic molecules are compounds containing carbon atoms bonded to hydrogen atoms and often other elements, like oxygen, nitrogen, and phosphorus. They are the building blocks of living organisms.

Sodium (Na) and Magnesium (Mg) share the same number of electrons in their outermost shell, called valence electrons. This influences their reactivity.

Hydrogen bonds form between a slightly positive hydrogen atom of one water molecule and a slightly negative oxygen atom of another water molecule.

Amino acids are the building blocks of proteins. Each amino acid has a central carbon atom, an amino group, a carboxyl group, and a unique R group.

Electronegativity is an atom's ability to attract electrons in a chemical bond. Highly electronegative atoms are located on the right side of the periodic table.

Isomers are molecules with the same chemical formula but different arrangements of atoms, leading to different properties.

The strength of hydrogen bonds between water molecules influences water's ability to move within plants, affecting their height. Stronger hydrogen bonds lead to taller plants.

Peptide bonds form between the carboxyl group of one amino acid and the amino group of another amino acid, linking them together to form a protein chain.

The initial RNA molecule produced during transcription before any processing, containing both introns and exons. It is a precursor for mRNA in eukaryotes.

The process of adding a tail of adenine nucleotides (poly-A tail) to the 3' end of a primary transcript in eukaryotes, protecting it from degradation and facilitating its export from the nucleus.

A process in eukaryotes where different combinations of exons can be joined together from a single primary transcript, generating multiple mRNA variants from a single gene.

The attraction between the nonpolar flat nitrogenous bases of nucleotides, leading to the stacking of bases on top of each other in DNA, providing stability and contributing to the double helix structure.

Proteins are made up of chains of amino acids linked together by peptide bonds.

The R group, also known as the side chain, is a variable part of an amino acid that gives it its unique structure and chemical properties.

Proteins fold into complex 3D shapes due to interactions between amino acids, including hydrophobic interactions, hydrogen bonding, and disulfide bridges.

The primary structure of a protein refers to the linear sequence of amino acids in the polypeptide chain.

An alpha helix is a secondary structure in proteins where the polypeptide chain coils into a right-handed helix, stabilized by hydrogen bonds.

A beta sheet is a secondary structure in proteins where polypeptide chains run parallel or antiparallel to each other, forming a sheet-like structure stabilized by hydrogen bonds.

The tertiary structure of a protein refers to its overall 3D shape, determined by interactions between R groups, secondary structures, and hydrophobic/hydrophilic interactions.

The tertiary structure of a protein is crucial for its function. It determines how the protein interacts with other molecules and performs its specific role in the cell.

The specific three-dimensional shape of a protein determines its function. This shape arises from the sequence of amino acids (primary structure) and influences how the protein interacts with other molecules.

Changes in environment (heat, pH, chemicals) can disrupt the delicate bonds maintaining protein structure, causing it to unfold and lose its function. This process is called denaturation.

Specialized proteins that help other proteins fold correctly and prevent them from denaturing in stressful conditions.

Ribosomes are cellular structures responsible for protein synthesis. They bind to mRNA and tRNA, providing a platform for translating the mRNA code into a polypeptide chain.

The first step in gene expression, where a DNA gene is copied into a messenger RNA (mRNA) molecule.

The second step in gene expression, where the mRNA code is read by ribosomes, and tRNA delivers amino acids to build a polypeptide chain based on the mRNA instructions.

The set of rules that determines how a sequence of three mRNA nucleotides (codon) specifies a particular amino acid during translation.

Translation is the process of converting the genetic information encoded in mRNA into a protein. It occurs in ribosomes and involves reading the mRNA sequence in codons (three-base sequences) and linking the corresponding amino acids together to form a polypeptide chain.

A codon is a three-base sequence in mRNA that codes for a specific amino acid or signals the start or stop of translation.

The start codon (AUG) signals the beginning of translation and codes for the amino acid methionine (Met).

Transfer RNA (tRNA) molecules act as adapters, bringing specific amino acids to the ribosome according to the mRNA codons. Each tRNA has an anticodon that recognizes a specific mRNA codon.

Translation has three stages: initiation, elongation, and termination.

Initiation involves bringing the mRNA, ribosome, and initiator Met-tRNA together. The ribosome binds to the 5' cap of mRNA and scans for the start codon (AUG), where the initiator tRNA binds and the large ribosomal subunit joins the complex.

Elongation involves the repeated addition of amino acids to the polypeptide chain. A tRNA carrying the correct amino acid binds to the A-site of the ribosome, a peptide bond forms between the amino acids, the ribosome moves along the mRNA, and the empty tRNA exits the ribosome.

Termination occurs when the ribosome encounters a stop codon. A release factor binds to the stop codon, causing the polypeptide chain to be released from the ribosome and the ribosome subunits to dissociate from the mRNA.

The first stage of translation where the ribosome binds to mRNA, the initiator tRNA carrying methionine attaches to the start codon (AUG), and the large ribosomal subunit joins the complex.

The process of adding amino acids to the growing polypeptide chain. tRNA carrying amino acids enter the A site, peptide bonds form, and the ribosome moves along the mRNA.

The final step of protein synthesis. A stop codon on the mRNA is reached, a release factor binds to the A site, and the polypeptide chain is released from the ribosome.

tRNA molecules act as adaptors, bringing specific amino acids to the ribosome based on the mRNA codons. They link the mRNA code to the amino acid sequence.

Specific three-nucleotide sequences (UAA, UAG, or UGA) on mRNA that signal the termination of protein synthesis.

Proteins that bind to the A site when a stop codon is reached, triggering the release of the polypeptide chain from the ribosome.

Changes made to a protein after it has been synthesized. Examples include folding, chemical modifications, and cleavage.

The process where the genetic information encoded in mRNA is converted into a sequence of amino acids forming a protein. It essentially translates the language of DNA into the language of proteins.