Transcription, Translation & Gene Regulation

What is the Central Dogma of molecular biology?

It describes the flow of genetic information from DNA to RNA to protein.

What sugar is found in DNA?

Deoxyribose.

What sugar is found in RNA?

Ribose.

What are the two main groups of bases in nucleic acids?

Pyrimidines and purines.

what nucleic acids belong to purines

Adenine and Guanine

what nucleic acids belong to pyrimidine

uracil, thymine, and cytosine

What is the role of transcription factors?

initiate gene transcription by recruiting RNA polymerase.

What is the function of RNA polymerase?

transcribes DNA to produce a complementary mRNA copy.

What is mRNA splicing?

The process of removing non-coding introns from the mRNA.

Where does mRNA translation occur?

In the cytoplasm at the ribosomes.

What is the start codon for translation?

AUG.

what is the stop codon for translation

UAA

What is the function of tRNA?

transports specific amino acids to the ribosome.

How many different tRNAs exist?

20 different ones

What is the role of the Golgi Apparatus in protein processing?

It processes proteins and directs them to the plasma membrane or internal organelles.

What is the secretory pathway?

The pathway through which proteins for export are synthesized in the rough ER and processed in the Golgi

What are enhancers in gene regulation?

Regions of DNA that increase the rate of transcription when bound by activators.

What are silencers in gene regulation?

Regions of DNA that decrease the rate of transcription when bound by repressors.

What is epigenetics?

The study of external modifications of genes that affect gene expression without changing the DNA sequence.

What is DNA methylation?

The addition of methyl groups to histones which changes the conformation of chromatin making it more compact, which can silence gene expression.

What is histone acetylation?

The addition of acetyl groups to histones, resulting in loosely packed chromatin and increased transcriptional activity.

How can diet influence epigenetic modifications?

Diet can modify epigenetic patterns, affecting gene expression and phenotype.

What is the significance of the agouti gene in mice?

It influences coat color and obesity; DNA methylation can switch it off.

What is the function of the rough endoplasmic reticulum (RER)?

It synthesizes proteins that are packaged into vesicles for export.

What happens to proteins in the Golgi apparatus?

They undergo post-translational modifications and are sorted for transport.

What are some of the post translation modifications of proteins

formation of disulfide bonds, proper folding, addition and processing of carbohydrates

What is gene regulation

how a cell controls which genes are expressed. it allows different cell types to express different sets of genes, leading to diverse functions.

what is gene regulation responsible for

spatial and temporal expression

what is spatial expression

not every gene product is needed in every cell

what is temporal expression

different genes are expressed at different times in response to a wide range of factors such as, heat, growth factors, hormones

What is the effect of environmental factors on the epigenome?

Environmental factors can lead to dynamic changes in the epigenome, influencing disease susceptibility.

how are genes regulated in the rate of transcription

enhancers and silencers

what do enhancers do in gene regulation

when an activator binds to the region it increases the rate of transcription

what does a silencer do in gene regulation

when a repressor binds to the region it depresses the rate of transcription

How is gene processing regulated?

alternative mRNA splicing to produce more than one protein product from a single gene

How is gene stability regulated?

Long lived mRNA are stable but short lived mRNA are unstable and are rapidly degraded