Transcription, Translation, Mutation

what are polymer of proetins

Nucleic acid

What si proteins made up of

polypeptide chain

What are some of the main functions of proteins

acts as enzyme, transport, regulate cell, communicate

where are proteins made

in ribosomes at the rough ER

Where is DNA found

Nucleus

why does DNA never leave the Nucleus

DNA is too valuable and too large so instead mRNA transportants the genetic info

How is DNA important to the synthesis of proteins

Indirectly codes for proteins as OG sequence determines mRNA sequence which will eventually be translated into amino acids to make the polypeptide

Template strand

Template strand is used for making complentry strand of RNA and runs 3’ to 5’

coding strand

the strand not used in transcription

What is the make up of DNA

Nitrogenous base, Deoxyribose 5 carbon sugar, phosphate group

how do nitrogen bases, phosphates, ect get into nucleus

through nuclar pores in lipid bilayer (cell membrane)

Differences of DNA and RNA

DNA has : Double stranded, deoxyribose sugar, thymine

RNA has : Single stranded, 5  carbon sugar ribose, uracil 

Gene definition

a segment of DNA the codes for a specific protein

Redundancy of Amino acids and codons

20 amino acids and 64 codons so some amino acids have multiple codons

What is RNA made up of

Nitrogen base, ribose 5 carbon sugar, phosphate group

what direction is RNA read and synthesized

5’ to 3’

true or false RNA strand is complementary to coding strand

FALSE RNA is complemnetry to TEMPLATE strand

what are the 3 main types of RNA

mRNA, tRNA, Ribosomal RNA

function of mRNA

carries info from DNA in nucleus to cytoplasm 

function of tRNA

Carries amino acids to the ribosome during translation to help synthesize polypeptide chain

ribosomal RNA

structural component of ribosomes

What is Transcription

process where genetic info from DNA is copied into synthesized complementary strand of RNA

where does transcription occur

Nucleus

Whats a promoter do in transcription

acts as a binding spot for RNA polymerase and marks start of teh gene

RNA polymerase

Unzips DNAs double helix, and synthesizes a complementary strand of RNA (builds 5’ to 3’)

Coding sequence

the part of the gene that is transcribed

terminator

signals the transcription to stop

3 phases of transcription

initiation, elongation, termination

What happens in transcriptions initiation

RNA polymerase binds to the promoter and unzips the double helix

What happens in transcriptions elongation

mRNA is synthezised 5’ to 3’ by RNA polymerase based off of template strand

What happens in transcriptions termination

terminator signals RNA polymerase to unbind, double helix rezips

Post Transcriptioin modifactions importance

Eukaryotic cells modify to make a mature mRNA

where does post transcription modifictions occur

nucleus

3 post transcription modifcations

splicing, GTP capping, polyadeynaltion

Splicing

removes intron which are non coding segments so they are unnecessary and keeps and fuses exons which ARE coding segments important to the RNA

GTP capping

adding a guanine triphospahte to the 5’ end of the RNA to prevent degrading and help ribsomes bind to the mRNA

Polyadenylation

Adding poly adenine tail to 3’ end to add stability and help move out of nucleus

what is translation

the process of synthezing a polypeptide

where does translation occur

at the ribsome/cytoplasm

what is the function of the small ribosomal unit

reads the mRNA codons and matches w tRNA anticodons to form amino acids

what is teh function of the large ribosomal subunit

 forms peptide bonds between the amino acids to make polypeptide chain

How many nucleotodes long is tRNA

About 100 nucleotides long 

functions of the tRNA

has amino acid bonding site w anticodon at bottom th euses hydrogen bonds to attach to matching codon

codon

3 nucleotides non overlaping

shape of tRNA

lowk t shape

what do codons reprsent

amino acid, start codon, stop codon

how many amino acids are there

20

how many codons are there

64

what are codons

specof info for amino acids

how are codons read

non overlapping fashion

how does P-site, A-site, E-site work

starts when a tRNA enter A-site and is moved down to P-site when others tRNA goes to A-site and when anther is added, Aminoacid chain is shofted to teh tRNA at P-site and the excess tRNA is moved to E-site where it exits.

what happens in translations initiation

mRNA binds to small ribosomal subunit and initiator tRNA is base paired w start codon MET/AUG, Large ribosomal subunit binds to small ribosomal subunit 

what happens in translations elongation

 small subunit reads codons and matches them w tRNA anticodons to form amino acids, peptide bonds are formed so that the amino acids are covalently attached to each other aka forming the polypeptide chain w P-site and A-site to form the peptide, and tsrabsloaction where the ribosome moves along tRNA strand and releases the P site at tRNA 

what happens in translation termination

stop codons have a release factor that signals the stop of translation and teh polypeptide is released and teh ribsomes subunits disassemble 

Post translation modifications

chemical change and addition of functional grousp such as phosphate and carbohydtate, specfic amino acids are cut through the clevage of exsiting elemnets

what are mutations

pernamnet changes in DNA

how do mutations occur

through error in DNA replication or enviromental factors such as UV exporuse, radiotion, amd chemicals

what cells do mutations affcet

somatic cells (body cells) and gamet cells (sperm and egg cells)

what mutation cells passes on mutations to off spring

gammets/de nova

Point mutations

change in one nucleotide resulting in larger change

substition

when 1 nucletodide is subsited for a differnet nucleotode

3 type of subsition

missense, silent, nonsesnse

Missense mutation

when a nucleotide changes an enitre amino acid reulting ina differnt protein

silent mutation

when a nuclotide cjanges but due to redudnacy, amino acid doesnt change

nonsense mutation

when a nuclotide changes and teh codon becomes a stop codon leading to an unfunctional proetin as the amino acid chain stopped too soon.

Frame Shift mutations

where an entire segment is inserted or deleted causing the sequence to shift forwrad or back wards

2 tyeps of frame shift mutations

insterion and deletion

insertion

when an entire nuclotide is added causing teh frame to shiftward, chaing entri eprotein

deletion

when an entire nuclkotide si deleted causing frame to shift nbackwards.