Alternative splicing is the process where different exons may be spliced, resulting in a single gene producing multiple different mRNA strands.
A molecule added to the 5’ end of pre-mRNA during RNA processing.
Translation involves reading and converting the information in the mRNA molecule into a polypeptide chain.
Nucleic acids are polymers made out of nucleotide monomers.
The production of functional gene products such as proteins or non-coding strands of RNA.
Transcription, RNA processing, and Translation.
The 5’ end of mRNA binds to the ribosome; the start codon (AUG) is recognized; tRNA with anticodon (UAC) delivers methionine to initiate translation.
Initiation, elongation, and termination.
The sequence of amino acids in a polypeptide chain.
The polypeptide chain is released by the ribosome into the cytosol or endoplasmic reticulum, where it is folded and modified into a fully functional protein.
The mRNA molecule can be reused to produce more polypeptides.
The genetic code relies on the grouping of adjacent nucleotides into groups of 3, which are essential for transcription and translation.
The operator region serves as the binding site for repressor proteins, which can inhibit gene expression.
Hormones are chemical messengers used to communicate and induce changes in cells.
Gene expression is the process of reading the information stored within a gene to create a functional product, typically a protein.
The repressor protein, when activated by high levels of tryptophan, binds to the operator region of the trp operon, blocking RNA polymerase and inhibiting transcription.
Transcription of structural genes necessary for tryptophan synthesis is prevented, conserving energy for the cell.
Disulphide bonds can form between cysteine amino acids to further stabilize the 3D structure.
RNA processing, also known as post-transcriptional modifications, involves the modification of the pre-mRNA molecule into an mRNA molecule that can be used in translation.
After post-transcriptional modifications, pre-mRNA exits the nucleus through a nuclear pore and travels to a ribosome in the cytosol or attached to the rough endoplasmic reticulum.
Non-coding regions of DNA that do not code for proteins and are spliced out during RNA processing.
Antiparallel describes how the two strands of DNA run in opposite directions; one runs 3' to 5' and the other runs 5' to 3'.
DNA consists of two polynucleotide chains that run antiparallel to each other.
Translation continues until a stop codon on mRNA is reached, signaling the end of translation, and the polypeptide chain is released.
The functional 3D shape of a protein, formed when secondary structures further fold and interact.
The bonding of multiple polypeptide chains together.
Monomers.
Insulin regulates blood sugar levels.
A structural gene is a segment of DNA that codes for proteins that play a role in the structure or function of a cell or organism.
Ribose
A terminator hairpin loop forms in the mRNA due to specific folding via hydrogen bonds.
An activator protein is coded for by a regulatory gene and increases gene expression.
RNA, or ribonucleic acid, is a single strand of nucleotides.
RNA contains ribose sugar instead of deoxyribose sugar and uses uracil instead of thymine. RNA is also single-stranded.
Catalase: Breaks down hydrogen peroxide into water and oxygen.
Precursor messenger RNA (pre-mRNA) is the immediate product of transcription of a DNA sequence, which requires modifications before it can undergo translation.
The two strands of DNA are bonded together via complementary base pairing.
The promoter region serves as a binding site for RNA polymerase, initiating transcription of the associated gene.
Primary, Secondary, Tertiary, and Quaternary.
A protein signaling molecule that regulates physiological behavior.
Introns are regions of non-coding DNA that do not contribute to the final protein and are removed during RNA processing.
Exons are regions of coding DNA that are transcribed and translated into the final protein.
Transcription ends at the termination sequence, RNA polymerase detaches, and pre-mRNA is released and processed into mRNA.
Polypeptide chains or proteins.
Amino acids
Structural genes are responsible for producing proteins involved in the structure or function of a cell, such as enzymes, transport proteins, receptors, or peptide hormones.
Low levels of tryptophan initiate the transcription of the trp structural genes to increase the amount of tryptophan available.
Activator proteins initiate or increase the expression of structural genes.
Ferritin acts as a storage reserve for iron.
Multiple chains
The leader region is the section of DNA just upstream of the coding region and downstream of the promoter and operator.
Alternative splicing allows for a single gene to give rise to many different mRNA strands and code for many different proteins.
rRNA serves as the main structural component of ribosomes within cells.
A molecule that is the smallest building block of a polymer.
The process where introns are cut out of a pre-mRNA molecule, and exons are joined together.
Stop codons signal for the termination of translation and do not code for a specific amino acid.
The chemical bond linking two amino acids.
Transcription is the process whereby a sequence of DNA is used as a template to produce a complementary sequence of mRNA.
Transfer RNA (tRNA) recognizes specific codons on the mRNA strand and adds the corresponding amino acid to the polypeptide chain during protein synthesis.
Active transport is the movement of molecules across a semipermeable membrane that requires an energy input.
An enzyme is an organic molecule, typically a protein, that catalyzes (speeds up) specific reactions.
3 bases
Structural genes are often found downstream (towards the 3’ end) of the regulatory gene that controls them.
A regulatory gene produces proteins that control the expression of other genes.
A repressor protein is coded for by a regulatory gene and prevents gene expression by binding to its operator.
Regulatory proteins can turn gene expression off or on and can increase or decrease the rate of gene expression by promoting or hindering transcription.
The ribosome pauses because there is no tRNA-bound tryptophan in the cell.
When the operator region is not bound with a repressor protein, RNA polymerase is free to move downstream from the promoter region, allowing for the transcription of the gene.
A prosthetic group is a non-protein group bound to a protein, such as a vitamin or ion.
Polypeptides
The sugar molecule present, the nitrogenous bases present, and whether they form single or double strands.
Transcription is the process whereby a sequence of DNA is used as a template to produce a complementary sequence of mRNA.
Regions of DNA that code for proteins and are not spliced out during RNA processing.
Messenger RNA (mRNA) carries genetic information from the nucleus to the ribosomes and is produced during transcription.
Transcription occurs entirely within the nucleus.
Bulk transport is a type of active transport that uses vesicles to move large molecules or groups of molecules into or out of the cell.
A common promoter sequence in eukaryotes is 'TATAAA', known as the TATA box.
Transcription factors bind to the promoter region, RNA polymerase binds, DNA unwinds, and transcription begins.
RNA polymerase moves along the DNA template, adding complementary RNA nucleotides to form pre-mRNA.
Each polypeptide chain is folded and modified into a fully functional protein, which can either remain in the cell or be exported out via exocytosis.
Monomers join together to form polymers through condensation reactions, resulting in peptide bonds between adjacent amino acids.
The structural genes in the trp operon are trpE, trpD, trpC, trpB, and trpA.
tRNA-bound tryptophan is delivered to the ribosome and incorporated into the growing protein.
The mRNA dissociates from the DNA template, and RNA polymerase detaches, halting transcription before structural genes are transcribed.
The chain of amino acids
Alpha helix and beta sheet
RNA polymerase continues along the DNA template.
The quaternary structure is formed when two or more polypeptide chains with tertiary structure join together.
tRNA delivers specific amino acids to the ribosome after recognizing specific nucleotide sequences on mRNA.
A chain of adenine nucleotides added to the 3’ end of pre-mRNA during RNA processing.
They are responsible for carrying genetic information and synthesizing proteins.
The start codon (AUG) codes for the amino acid methionine.
A reaction where two monomers join to form a larger molecule, producing water as a by-product.
They stabilize the mRNA molecule, preventing degradation and allowing it to bind to ribosomes during translation.
Collagen provides support in connective tissues such as the skin.
mRNA is fed through the ribosome; codons are matched to tRNA anticodons; tRNA delivers amino acids, forming peptide bonds; tRNA is released for the next amino acid addition.
The protein secretory pathway involves various organelles, primarily ribosomes, rough endoplasmic reticulum, Golgi apparatus, and transport and secretory vesicles, that produce, fold, modify, and package proteins for export.
It is formed when a polypeptide chain folds and coils by forming hydrogen bonds between amino acids, resulting in structures like alpha-helices and beta-pleated sheets.
Exocytosis can eliminate waste from the cell, preventing toxin build-up by releasing waste products into the extracellular environment.
mRNA carries the message for protein synthesis to the ribosomes.
Trp operon attenuation stops transcription by prematurely ceasing translation.
Transcription and translation begin simultaneously.
High levels of tryptophan stop the transcription of the trp structural genes to prevent unnecessary production of tryptophan.
5 carbon atoms
Attenuation occurs when transcription of the trp structural genes begins but is stopped early before any proteins are made, in response to the amount of tRNA-bound tryptophan.
An operon is a group of multiple structural genes that share a common purpose and are controlled by a single promoter and operator.
The attenuator sequence contains two consecutive trp codons.
Transcription and translation continue.
The leader region plays a critical role in regulating gene expression in prokaryotes.
Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
All the proteins that are expressed by a cell or organism at a given time.
A nucleotide includes a phosphate group, a five-carbon sugar, and a nitrogen-containing base.
The fluid nature of the plasma membrane facilitates exocytosis by enabling it to fuse with vesicles, allowing for the release of substances from the cell.
A triplet is the sequence of three nucleotides in DNA coding for one amino acid.
The termination sequence signals for the end of transcription.
Transcription and translation are allowed to proceed, facilitating increased tryptophan production.
The trp operon regulates the expression of structural genes that code for proteins involved in the production of the amino acid tryptophan.
Receptors receive signals from the environment.
Antibodies are involved in the immune system by recognizing and destroying pathogens.
The operator is a short region of DNA that interacts with repressor proteins to alter the transcription of an operon.
An operon is a cluster of linked genes that all share a common promoter and operator and are transcribed at the same time.
mRNA carries genetic information from the nucleus to the ribosomes for protein synthesis.
A phosphate group, a five-carbon sugar, and a nitrogenous base.
During the translation of mature mRNA, a sequence of amino acids is formed, ultimately creating a polypeptide chain.
A large molecule that is made up of small, repeated monomer subunits.
The stages of exocytosis include: 1. A vesicle containing secretory products is transported to the plasma membrane. 2. The membrane of the vesicle fuses with the plasma membrane. 3. The secretory products are released from the cell into the extracellular environment.
The creation of pre-mRNA by converting genetic information from DNA into RNA.
Translation is the process where an mRNA sequence is read to produce a corresponding amino acid sequence to build a polypeptide.
The enzyme that removes introns from the pre-mRNA molecule and joins exons together during RNA processing.
Translation is the process where an mRNA sequence is read to produce a corresponding amino acid sequence to build a polypeptide.
Ribosomal RNA (rRNA) is a key structural component of ribosomes, which assemble proteins.
A codon is the sequence of three nucleotides in mRNA coding for one amino acid.
Each R group has its own chemical properties, affecting interactions between proteins.
In prokaryotes, transcription occurs directly in the cytoplasm, while in eukaryotes, it occurs in the nucleus.
Regulatory genes code for proteins that influence the expression of structural genes.
Deoxyribose
Polypeptides
The attenuator sequence is found at the end of the leader region of the trp operon.
3D Structure
The trp operon contains genes involved in the production of the amino acid tryptophan, which can be used in protein production.
Enzymes are organic catalysts that speed up chemical reactions by reducing the activation energy.
Exocytosis is the process by which contents of a vesicle are released from a cell, allowing for the movement of large substances such as proteins out of the cell.
Transport proteins control the entry and exit of substances from a cell.
Initiation, elongation, and termination.
Keratin: A tough protein found in skin, hair, and nails.
A protein produced by plasma cells during immune response that is specific to an antigen and combats pathogens in various ways; also known as immunoglobulin.
Amino acids, which have a chemical structure composed of a central carbon atom, carboxyl group, amino group, an R-group, and a hydrogen atom.
The antiterminator hairpin loop prevents mRNA dissociation from the template strand.
Gene regulation is the control of gene expression, typically achieved by switching transcription on or off.
The ribosome translating the mRNA reaches the attenuator sequence, which codes for two tryptophan amino acids.
Acetylcholine receptors are an example.
Repressor proteins inhibit or decrease the expression of structural genes.
Myosin and actin work together to enable muscle contractions.
The promoter is the sequence of DNA to which RNA polymerase binds.
Kinesin moves along microtubules, enabling mitosis and vesicular transport.
Different somatic cells express different genes to produce the appropriate proteins, even though they are genetically identical.
An enzyme is an organic molecule, typically a protein, that catalyzes specific reactions.
When the operator region is bound with a repressor protein, RNA polymerase cannot move downstream from the promoter region, inhibiting transcription of the gene.
The formation of an antiterminator hairpin loop in the mRNA prevents termination.
