Nucleic acids and gene expression Flashcards
Ribo and deoxyribo Nucleotides
- what do they make up
- structure of a nucleotide
- DNA and RNA
- 5 carbon pentose sugar (RNA ribose sugar. DNA deoxyribose sugar- no oh group)
- Bases- 2 ring purines adenine and guanine. 1 ring pyrimidines thymine (uracil in RNA) and cytosine). Nitrogen 9 of the base bond with carbon 1 of sugar.
- Phosphoryl group - o2 of phosphate group binds to carbon 5 of sugar
primary structure-
- how are nucleotides joined
- what part of the nucleotide varies
- what is the primary structure
- structure of DNA vs RNA
- why is primary structure important
- by phosphodiester bonds between adjacent carbons of deoxyribose sugars (3’ and 5’)
- the bases
- the base sequence
- DNA has double helix secondary structure, RNA is single stranded
- codes for different proteins
what are histone proteins
- they anchor and support DNA to allow dense packing within cells as chromosomes
dna replication-
- what it allows
- how does it happen
- allows cells to divide an duplicate its genetic material during mitosis/cell cycle
- DNA helicase breaks hydrogen bonds to unzip/separate DNA molecule
- Small strip of RNA primer binds and kick starts replication
- DNA polymerase adds complemetary base pairs in the 5’ to 3’ direction building a new DNA molecule to wrap round the parental strand
- Exonuclease removes the original primers and the bases are then readded to complete a new DNA double helix
dna mutations-
- how do they occur
- how do mutations and evolution link
- impact of training on genes
- Bases can be inserted, deleted or substituted incorrectly resulting in change in protein formed
- Advantageous mutations are basis of darwins theory of evolution (mutation increasing chance of survival)
- can increase the expression of specific genes and therefore make particular proteins more abundant
3 types of RNA
○ Messenger RNA- decodes DNA
○ Ribosomal RNA- Decodes mRNA
○ Transfer RNA- facilitates protein formation during translation
transcription-
- what is the end result
- process of transcription
- what is a promoter region
- what is an enhancer region
- what are transcription factors
- Process of creating a single mRNA strand from DNA
- DNA helicase unwinds DNA and RNA polymerase replicates DNA template to form mRNA primary transcript (5’ to 3’)
- next to transcription site that docks RNA polymerase
- attract the transcription factor complex proteins
- proteins that regulate the rate of mRNA formation
impact of exercise on gene expression
- Different types of exercise can result in different regions of the gene being copied forming different mRNA and therefore proteins, eg.
- PGC-1a4 - activated following strength training resulting in hypertrophy and strength.
- PGC-1a1 - activated following endurance training resulting in oxidative muscle
mRNA splicing-
- what happens to primary mRNA transcript
- what is alternate splicing
- non coding regions (introns) are spliced out leaving the coding regions (exons) which form the mature mRNA.
- exons from the same gene are joined in different combinations in mature mRNA leading to different isoforms of proteins
translation-
- what is it basically
- process of translation
- formation of a polypeptide chain from a mature mRNA transcript
- mRNA binds to the small subunit of ribosome
- A 3 base sequence on mRNA (codon) is complementary to a 3 base sequence on transfer RNA (anti-codon) which binds to the large subunit of rRNA holding a specific amino acid
- This occurs down the mRNA in the 5’ to 3’ direction and each amino acid joins by a peptide bond forming a polypeptide chain
quality control of proteins-
- role of the ER
- role of the golgi apparatus
- what happens to the proteins
- contains various proteins that fold the protein to form its tertiary structure
- governs post-translational modifications (eg. Glycolysation, phosphorylation)
- released from the cell or trafficked to organelles or cell membranes
