Nucleic Acids & Proteins Units 5 & 6. Nucleic Acids Nucleic Acids are Polymers made of...

Nucleic Acids & Proteins

Units 5 & 6

Nucleic AcidsNucleic Acids are Polymers made of Nucleotides

3 Parts:

a)Phosphate groupb)5-Carbon Sugarc)Nitrogen base

2 Types: DNA & RNA

b) 5-Carbon Sugar

a) Phosphate Group

c) Nitrogen Base

THYMINE URACIL

Nitrogen Bases Pyrimidines = C, T, & U

Purines = A & G

Pyrimidines ALWAYS bond to Purines

G bonds to CA bonds to T or U

Single ring

Double ring

Pyrimidines

Purines

RNA Sugar = Ribose

RNA is Single Stranded

RNA has Uracil

Sugar & phosphate backbone

Nitrogen Bases

DNA Sugar = Deoxyribose

DNA is Double Stranded

DNA has Thymine

Sugar & phosphate backbone

Nitrogen Bases

Hydrogen Bonds

A bonds to T; G bonds to C

Hydrogen bonds hold Nitrogen bases together to form the Double helix

DNA

DNA is found in the Nucleus of eukaryotic cells in the form of

Chromosomes 

Sections of DNA that code for a protein are

called Genes Chromosomes are made of DNA wound around proteins called

Histones 

Homologous chromosomes have

the same Genes (possibly different

alleles) 

DNA ReplicationOriginal strands are used as a

Pattern/Template to build new Complimentary DNA strands

Enzymes help with this process:

Helicase breaks the hydrogen bonds between the complimentary strands

DNA Polymerases build the new strands and then proofread the nucleotide sequence

2 Identical DNA molecules are

produced.

Each molecule is made of one

ORIGINAL strand and one NEW strand.

Semi-conservative DNA Replication

ENZYMES of DNA Replication

UNZIPS STRANDS

ADDS NEW NUCLEOTIDES

Leading strand (3’ end)

Lagging strand (5’ end)

DNA polymerase can only move towards the 5’ end of the

original DNA molecule

(New DNA is built 5’ to 3’)

This means the Lagging strand is built in small sections

called Okazaki fragments. 

Central Dogma

DNA RNA Protein

Protein Synthesis

Transcription Translation

Protein Functions: Transport of substances, Enzymes that control the rate of reactions, provide Support, build Tissues, & fight Infections

3 Central Carbon

4 Amino Group5 Hydrogen

6 Carboxyl Group

7 R Group

Proteins are Polymers made of Amino Acids

4 Parts:

Central Carbon

Amino group

Hydrogen

Carboxyl group

& R group

3 Types of RNA• mRNA = Copy of gene/DNA (instructions for making the

protein)• tRNA = Translates/Decodes mRNA and Transfers/Delivers

amino acids to the ribosome in the correct sequence• rRNA = Ribosomes are made of rRNA which Bond amino

acids together to build the Polypeptide (protein)

a) Messenger RNA b) Ribosomal RNA c) Transfer RNA

Transcriptionthe process of Copying DNA into the complimentary sequence of mRNA

The enzyme that copies the DNA (gene) into mRNA is

RNA polymerase

No T in RNA so A bonds to U

RNA Polymerase

Works just like DNA polymerase EXCEPT it adds RNA nucleotides

Transcription

occurs in the Nucleus

TranslationBegins when the mRNA leaves the nucleus and goes to the

Ribosome

tRNA decodes the mRNA 3 bases at a time

Codon = 3 base sequence on mRNA

Codons are complimentary to the Anticodons on the tRNA

rRNA forms Peptide bonds between Amino Acids to form the

Polypeptide (protein)

Translation

 Anticodon

 Amino Acid

 Codon

Transcribe the following DNA into mRNA

DNA: TAC – CCG – GAT – TAG – ATC

mRNA: ____ - ____ - ____ - ____ - ___

Translate the above mRNA into the correct sequence of Amino Acids using

the Codon Chart

Protein: ____ - ____ - ____ - ____ - ____ 

AUG GGC CUA AUC UAG

Met Gly Leu Ile STOP

1 DNA = Template

2 mRNA built by RNA polymerase

3 Codons on mRNA

4 mRNA goes to ribosome

5 tRNA carries amino acids

6 tRNA Anticodon decodes mRNA codons

7 Amino acid bonded to Polypeptide

8 tRNA goes to pick up another Amino Acid