Nucleic Acids

• Organic molecules to store genetic information and transmit genetic information for future generations

DNA and RNA

DNA - DEOXYRIBONUCLEIC ACID

• blueprint of life (has the instructions for making an organism’s proteins)

• established by James Watson, Francis

Crick & Rosalind Franklin• codes for your genes • shape of a double helix • made of repeating

subunits called nucleotides

• Nucleotide - consists of a sugar, phosphate and a base- A,G,T,C

•Gene - a segment of DNA that codes for a protein, which in turn codes for a trait (skin tone, eye color..etc), a gene is a stretch of DNA.

ReplicationMaking new DNA from existing DNA.

•Happens during the S phase of Interphase.•Ensures each daughter cells is an exact copy of the parent cell.•Assisted by enzymes called DNA polmerase.

Uses DNA base pairing rules.

RNA - RIBONUCLEIC ACID3 types ~mRNA, tRNA & rRNA

• RNA is similar to DNA except:

1. has one strand instead of two strands.2. has uracil instead of thymine3. has ribose instead of deoxyribose

Transcription & Translation

Transcription is making the mRNA to be used in protein synthesis Translation

is the actual synthesis of the protein needed to build the organism

Transcription

• Happens in the Nucleus• Creates mRNA that can leave the nucleus• Uses base pairing rules of:

A-U, T-A, C-G & G-C

Translation

RNA Reunion

• Happens at the ribosomes (in cytoplasm & the rough ER).

• ALL 3 RNA types are involved.• Uses 20 amino acids as the ingredients for EVERY

LIVING THING on our planet!!• Actual synthesis of the polypeptide (protein)

Amino acids 1.Every 3 bases on the mRNA is called a codon.

2.Each codon is the “code” for 1 particular amino acid out of 20.

3.Amino acids are the monomers of proteins!

• Codon UUU is ____?

Codon GGG is ____ ?

Codon UGA is ____ ?

Codon AGT is ____ ?

PRACTICE!!Page 303 in your book!

• DNA STRAND:TAC TTC CGA GCG CCT CAT

ACT• mRNA Strand (transcription):

_______________________________

• Amino acid sequence (translation):

_________________________________

PRACTICE ANSWERS!!

• DNA STRAND:TAC TTC CGA GCG CCT CAT ACT

• mRNA Strand (transcription):

AUG AAG GCU CGC GGA GUA UGA

• Amino acid sequence (translation):

Methionine-Lysine-Alanine-Arganine-Glycine-Valine- STOP

mRNA is the messenger RNA that holds the “recipe” to put the protein together.

tRNA transfers the correct amino acid from the cytoplasm to the ribosome

rRNA physically makes up part of the rbosomes – the “factory” of protein synthesis

polypeptide Amino acid

tRNA

anti-codon

codon

mRNA

rRNA(ribosome)

Nucleic Acid Processes

MutationsANY change in the DNA.

ChromosomalMutations involve chromsomes in part or whole.

Inversion

Translocation

Deletion

Duplication

Mutations

Gene mutationsHappen with individual nucleotides!

Substitution

Frameshift mutations are caused by adding 1 nucleotide or deleting 1 nucleotide. Changes the “reading frame” of the codons!!