DID YOU KNOW?????

DID YOU KNOW?????Elephants

have been known to remain standing after they die.

DNA, RNA and Protein Synthesis

Chapters 12

PROTEIN REVIEW Proteins are large molecules formed by

smaller molecules called amino acids. Amino acids are known as the building

blocks of proteins. In your body, proteins aid in muscle

contractions, give structure to cells and act as enzymes.

GENES A segment of DNA that codes for a

protein. DNA is organized into units called

genes. Found in the nucleus. Contain instructions on how to make

proteins.

Nucleic AcidsBoth DNA and RNA are known

as nucleic acids.Just like the building block for

proteins are amino acids, the building blocks for nucleic acids are NUCLEOTIDES.

Who discovered DNA? In 1953, Watson

and Crick were the first to identify the structure of DNA.

Won a noble prize in 1962.

DNA Deoxyribonucleic acid Fundamental building block of all

living things. Passes on information from

generation to generation by duplicating itself.

The Structure of DNAShaped like a

double helix – two strands twisted around each other like a winding staircase.

NUCLEOTIDES Building blocks of DNA. Subunits that make up DNA. Each consist of 3 parts:

1. Five carbon sugar called deoxyribose

2. Nitrogen base3. Phosphate group

NUCLEOTIDE Make sure you know how to draw and label

this!

Phosphate group

Nitrogenous base

5 Carbon Sugar: DEOXYRIBOSE

NITROGENOUS BASES Four different nitrogen bases in DNA:

1. Adenine Purines2. Guanine3. Thymine Pyrimidines4. Cytosine

NUCLEOTIDE The only part that changes in a DNA

molecule is the nitrogenous base!

Phosphate group

Nitrogenous base

5 Carbon Sugar: DEOXYRIBOSE

1. ADENINE2. THYMINE3. GUANINE4. CYTOSINE

Warm Up

1. What are the building blocks of DNA?

2. Name one thing proteins do in your body.

3. What is a gene?

ANSWERS 1. What are the building blocks of

DNA? NUCLEOTIDES2. Name one thing proteins do in your

body. AID IN MUSCLE CONTRACTIONS.

3. What is a gene? SEGMENT OF DNA LOCATED ON A CHROMOSOME.

Did you know??????????????????? A cockroach can live

for several weeks without it’s head!

Complementary Base Pairing ONLY CERTAIN BASES CAN LINK

TOGETHER. THESE BASES ARE CALLED “COMPLEMENTARY”.

A always pairs with TC always pairs with G

* Bases are held together by hydrogen bonds.

Complementary StrandsFill in the blanks:One side of DNA: ACTGGCTATGC

Other side : TGACCGATACG

DNA ReplicationProcess of making a copy of DNA.

One DNA strand serves as a template tobuild the other.

1st the DNA strand “unzips” or splits down the middle.2nd Complementary nucleotides attach to the single strands

What if there are mistakes?Sometimes the wrong nucleotides are added.

An enzyme called DNA polymerase proof reads the strand and checks for errors in the nucleotide pairings.

The chance in a mistake is reduced to 1 error per every billion nucleotides!

FROM GENES TO PROTEINS: Decoding the information in DNA

Traits such as eye color as encoded in DNA.

How are these traits passed on from generation to generation?

This job takes both DNA and something called RNA.

FROM GENES TO PROTEINS: RNA

Like DNA, RNA is a nucleic acid, ribonucleic acid. RNA differs from DNA in 3 ways.

DNA RNA

Double stranded Single stranded

Sugar is deoxyribose

Sugar is ribose

Nucleotides ACTG

Nucleotides ACUG

Warm Up 1. The sugar in DNA is called

______________, while the sugar in RNA is called____________________.

2. What are the two steps of DNA replication?

WARM UP ANSWERS 1. The sugar in DNA is called

DEOXYRIBOSE, while the sugar in RNA is called RIBOSE.

2. What are the two steps of DNA replication? 1. DNA MOLECULE UNZIPS 2. NUCLEOTIDES ATTACH TO THE NEW STRAND.

DID YOU KNOW?????????????

IF YOU HAVE HAD YOUR PILLOW

FOR OVER 5 YEARS, ONE TENTH OF IT’S TOTAL WEIGHT IS DUST MITES AND

THEIR POOP!

FROM GENES TO PROTEINS: Uracil instead of Thymine

No thymine bases are found in RNA, instead uracil pairs with adenine.

DNA RNA A-T A-U C-G C-G

From DNA to RNAOriginal DNA strand

ATTACGAAGGCTA

UAAUGCUUCCGAU

New RNA strand

THREE TYPES OF RNA

1. mRNA- messenger RNA2. tRNA- transfer RNA3. rRNA- ribosomal RNA

We will learn more about these later.

FROM GENES TO PROTEINS: The Big Picture

2 STEP PROCESS:1st. TRANSCRIPTION- from DNA to

RNA2nd. TRANSLATION - from RNA to

proteins.

FROM GENES TO PROTEINS: Transfer of Information, From DNA to RNA

TRANSCRIPTION – process of taking information found in DNA and transferring it to a RNA strand. RNA is produced. Genetic information encoded in DNA is transferred to an RNA molecule.

Occurs in the nucleus, where DNA is found.*******THIS IS NOT THE SAME AS DNA REPLICATION*********

Transcription vs. Replication

FROM GENES TO PROTEINS: Results of Transcription

FORMATION OF ONE SINGLE-STRANDED

RNA MOLECULE

FROM GENES TO PROTEINS: mRNA

-The type of RNA that carries out transcription is called mRNA.

-mRNA will deliver the new strand to the site of translation.

WARM UP 11/151. NAME THE THREE TYPES OF RNA.2. WHAT IS THE RESULT OF

TRANSCRIPTION?

Warm up Answers 11/151. NAME THE THREE TYPES OF RNA.

1. Messenger RNA2. Transfer RNA3. Ribosomal RNA

1. WHAT IS THE RESULT OF TRANSCRIPTION? The formation of one single stranded RNA molecule.

DID YOU KNOW????????????The average human

produces a quart of saliva a day!! That’s about 10,000 gallons in a lifetime!

Why do we need mRNA? Remember, DNA is only found in the nucleus of the

cell. mRNA is needed to carry information out of the

nucleus to other parts of the cell.For example,

Imagine that your name is DNA and you areon house arrest. If you need McDonalds you mustsend someone else with your message (order) toMcDonalds.

FROM GENES TO PROTEINS: The Genetic Code, Codons

The mRNA instructions are written as three nucleotide sequences called CODONS.

Each nucleotide triplet in mRNA specifies for a particular amino acid.

Each codon along the mRNA strand corresponds with a specific amino acid.AUC GGA UUA CCC CODON CODON CODON CODON

mRNA codes for Specific Amino Acids

mRNA AUC GGA UUA CCC

CODON CODON CODON CODON

Isoleucine Glycine Leucine Proline

Now you try…………… UAA Stop UGU Cysteine GAU Aspartic acid

FROM GENES TO PROTEINS: RNA’s Roles in Translation

Takes place in the cytoplasm at the ribosomes. In order for translation to occur, mRNA must migrate to the ribosomes.

tRNA and ribosomes help in the synthesis of proteins. Proteins are made from mRNA.

The mRNA moves out of the nucleus to the ribosomes. There tRNA carries the amino acid to it’s correct codon. The sequence is then converted into an amino acid sequence.

FROM GENES TO PROTEINS: Translation

tRNA consists of a single strand of RNA with an amino acid linked to the end.

Each tRNA contains an anticodon – three nucleotide sequence that is complementary to an mRNA codon.

From DNA mRNA tRNA ProteinsDNA Strand ATCGATCCG

mRNA Strand UAGCUAGGC codons

tRNA Strand AUCGAUCCG anti-codons

Proteins Isoleucine, etc

What happens when there is a mistake? Normally process is very accurate, but

occassionaly they make a mistake known as a mutation.

ex. THE DOG BIT THE CAT THE DOG BIT THE CAR

**One change can make a huge difference!

3 Types of Mutations1. Point mutation – only a single nucleotide

changes. (Only changes one protein)ATCGAA Serine, ArginineATGGAA Stop, Arginine

2. Deletion mutation – base is removed or entire segments.

THE CAT ATE THE ATA TE

3. Frameshift mutation – base is added or deleted, causes a change in all of the amino acids after the mutation. Causes the gene to be read wrong. Ex. Include deletion and addition mutations.

Warm UpSTUDY FOR YOUR QUIZ –

WHICH WILL BEGIN 10 MINUTES AFTER THE BELL!