DNA->RNA-> Protein

The Central DogmaReplication-> Transcription-> Translation

Modified from Kim Foglia

Bodies are made up of cells All cells run on a set of

instructions spelled out in DNA ( deoxyribonucleic acid)

Bodies Cells DNA

How does DNA code for cells & bodies? DNA synthesized ( REPLICATION)->RNA-> proteins->cells

DNA Cells Bodies

DNA has the information to build proteins genes

DNA Proteins Cells Bodies

proteinscells

bodiesDNA gets all the glory,Proteins do all the work

cytoplasm

nucleus

Cell organizationDNA

DNA is in the nucleus▪ genes = instructions for making proteins

want to keep it there = protected▪ “locked in the vault”

Building the polymer

Nitrogenous bases 2 types of nucleotides

different nitrogen bases purines▪ double ring N base ▪ adenine (A)▪ guanine (G)

pyrimidines▪ single ring N base ▪ cytosine (C)▪ thymine (T)▪ uracil (U)

Purine = AGPure silver!

Base Pairs Nucleotides bond between

DNA strands H bondsphosphodiester bonds purine :: pyrimidine A :: T▪ 2 H bonds

G :: C▪ 3 H bonds

Matching bases?Why is this important?

Passing on DNA information

Need to get DNA gene information from nucleus to cytoplasm need a copy of DNA messenger RNA

nucleus

cytoplasm

ribosome

mRNA

buildproteins

aa

aa

aa

aa

aa

aa

aa

aaaa

aa

DNA vs. RNADNA

deoxyribose sugar nitrogen bases

G, C, A, T T : A C : G

double stranded

RNA ribose sugar nitrogen bases

G, C, A, U U : A C : G

single stranded

Transcription ( DNA->RNA)

Making mRNA from DNA DNA strand is the

template (pattern) match bases▪ U : A▪ G : C

Enzyme RNA polymerase

RNA structure

Ribonucleic acid RNA nucleotide ( ribose, phosphate,

AUCG) Phosphodiester bonds Synthesis ( transcription) nucleolus

Types of RNA

Messenger RNA: carries coded instruction for protein synthesis

Transfer RNA: carries specific amino acids to ribosomes during protein assembly

Ribosomal RNA: part of ribosomes

How does mRNA code for proteins

mRNA leaves nucleus mRNA goes to ribosomes in

cytoplasm Proteins built from instructions on

mRNA

aa aa aa aa aa aa aa aa

mRNA

U C CCCCCA A U G U G A A A A AG G G GU U

Cell organization Proteins

chains of amino acids made by a “protein factory” in cytoplasm protein factory = ribosome

nucleus

cytoplasm

ribosome

aa

aa

aa

aa

aa

aa

aa

aaaa

aa

buildproteins

How do proteins do all the work

Proteins proteins run living organisms enzymes▪ control all chemical reactions in living

organisms structure▪ all living organisms are built out of proteins

Proteins

Building block =

aminoacid

aminoacid–

aminoacid–

aminoacid–

aminoacid–

—N—H

H

H|—C—|

C—OH

||O

variable group

amino acids

20 different amino acids

Amino acid chains Proteins :amino acids chained into a

polymer, primary structure held by peptide bonds

Each amino acid is different some “like” water & dissolve in it some “fear” water & separate

from it

amino acid amino acid amino acid amino acid amino acid

Protein structure

Primary structure: chain of amino acids held by peptide bonds

Sensitive to temperature, pH and ionic conditions

Protein synthesis occurs on ribosomes

DNA Replication

mRNA

From nucleus to cytoplasm

DNA

transcription

nucleuscytoplasm

translation

trait

aa

aa

aa

aa

aa

aa

aa

aaaa

aa

protein

From gene to protein

transcriptiontranscription

translationtranslation

proteinprotein