4.2 GENE EXPRESSION: TRANSCRIPTION AND TRANSLATION

what is apart of a DNA nucleotide

deoxyribose, cytosine, thymine, phosphate group, adenine, and guanine

base pair rules for DNA

A:T G:C

base pair rules for RNA

C:G A:U

how the structures of DNA and RNA are different

the sugar in DNA is deoxyribose in RNA it is ribose, DNA has thymine and RNA has uracil, DNA is double stranded and RNA is single stranded

how the locations of DNA and RNA are different within the cell

DNA is only found in the nucleus and RNA is found in both the nucleus and cytoplasm

messenger RNA (mRNA)

long chain of nucleotides that carries genetic instruction for making proteins from the DNA in the nucleus to the ribosome out in cytoplasm

transfer RNA (tRNA)

chain of nucleotides folded into a hairpin structure with amino acid attachment site at top and 3 letter anticodon at bottom that transports and transfers amino acids to the ribosome during protein synthesis.

ribosomal RNA

chain of nucleotides that is folded into a globular shape, shorter small subunit and longer large subunit which has 3 sites A,P,E which come together to form functional ribosome that is able to follow genetic instructions to make proteins

messenger RNA

type of RNA that carries genetic instructions from the DNA to ribosome

transcription

the process of making a molecule of mRNA from a gene in DNA

RNA polymerase

the major enzyme responsible involved in transcription

gene

a sequence of DNA that codes for a particular protein

nucleus

location of the cell containing DNA that controls cell activities

cytoplasm

location of the cell between the nucleus and cell membrane, site of most activities

transcription

the process of transcription occurs in the nucleus of eukaryotic cells occurring in three steps

initiation

the enzyme RNA polymerase finds the promoter region on the DNA and begins separating the DNA strands

elongation

RNA polymerase follows the base-pair rules to match RNA nucleotides with the complementary DNA nucleotide to build the primary transcription

termination

RNA polymerase finds the termination sequence releasing the primary mRNA transcript

messenger RNA

the type of RNA that carries genetic instructions from the DNA to ribosome

transfer RNA

the type of RNA that carries amino acids to the ribosome

ribosomal RNA

the type of RNA that makes up the structure of the ribosome

codon

three letter sequence of mRNA that specifies for a particular amino acid

genetic code

the chart that correlates codons and amino acids

translation

the process of making a protein from a sequence of mRNA

ribosome

organelle that builds proteins

amino acid

the building blocks of proteins

protein

biological macromolecule made from amino acids, performs most cell functions

the modifications to the pre-mRNA that occurs before the mRNA leaves the nucleus

the primary transcript needs to be processed in several ways before leaving the nucleus enzymes cut out the non-coding intron sequences and splice together the coding exon sequences. a GTP is added to the 5’ end of the molecule and a poly-a-tail, a chain of anywhere between 50 to 200 adenine nucleotides, is added to the 3’ end if the molecule

mutation

a mutation is a change in the sequence of DNA nucleotides

how mutations occurs within cells

Mutations can occur due to errors during DNA replication, exposure to environmental factors like radiation or chemicals, or through viral infections. These changes can lead to alterations in gene function, potentially affecting protein synthesis and cellular function.

difference between a point mutation and frameshift mutation

A point mutation involves a change in a single nucleotide, while a frameshift mutation occurs due to the insertion or deletion of nucleotides, altering the reading frame of the genetic code.

difference between a missense and a nonsense substitution mutation

A missense mutation results in the substitution of one amino acid for another in a protein, while a nonsense mutation creates a premature stop codon, leading to a truncated protein.

difference between an insertion and deletion mutation

An insertion mutation adds one or more nucleotides into the DNA sequence, while a deletion mutation removes one or more nucleotides, both potentially leading to frameshift effects.

the process of translation (cytoplasm, ribosome, mRNA, codon, anticodon, tRNA, amino acid, and proteins)

The process of translation is the synthesis of proteins from mRNA in the ribosome, where codons on the mRNA are matched with corresponding anticodons on tRNA, bringing specific amino acids together to form a polypeptide chain.