DNABlueprints of life

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WHAT IS DNA? DNA stands for: DeoxyiriboNucleic Acid Code that stores a cell’s hereditary

materialContains info for cell’s growth and function

DNA is copied during passed on to daughter cells during cell division

BrainPop

STRUCTURE OF DNA 1952: Scientist Rosalind Franklin

discovers the Double HelixTwo chains of molecules in a spiral formSimilar to a twisted ladder

Referred to as “Twisted Ladder” Each side of the ladder is made up of

sugar-phosphate molecules Each molecule consists of the sugar

called dioxyribose and a phosphate group

STRUCTURE OF DNA The “rods” of the ladder are made up of

other molecules called nitrogen bases Nitrogen bases occur in pairs

Adenine (A)- Thymine (T)Guanine (G) – Cytosine (C)

How does DNA replicate?

Ladder “un-zips” Each side becomes a pattern for the

new DNA strand to build off of New DNA has bases that are identical to

the original DNA

Video Clip

DNA REPLICATION

GENES DNA contains “instructions” for making

the proteins that determine a person’s characteristics

Gene – section of DNA on a chromosome where the instructions are found

Proteins are composed of amino acids Genes determines the order of the amino

acids Each cell of your body only uses a portion

of the thousands of genes in your DNA

Where are genes found?

Video Clip

PROTEIN SYNTHESIS Made in the ribosomes of a cell RNA – RiboNucleic Acid

code for making proteins

RNA Structure is similar to ½ of a ladder Ribose - sugar phosphate molecule in

RNA RNA nitrogen bases occur in pairs

Adenine (A) - Uracil (U)Guanine (G) -Cytosine (C)

BrainPop

TYPES OF RNA

Type Description

Messenger(mRNA)

- Begins protein Synthesis- Provides code that directs sequences for amino acids

Ribosomal(rRNA)

- What Ribosomes are composed of

Transfer(tRNA)

- Serves as the “link” between mRNA and amino acids sequence of

proteins

MUTATIONS Mutation: any permanent change in

the DNA Sequence Occurs when DNA is not copied exactly Examples: extra chromosome, missing a

chromosome X-rays, sunlight, and some chemicals

can also cause mutations

BrainPop

RESULT OF A MUTATION May or may not be life threatening If mutation occurs in a sex cell, then all

cells that form from that cell will also be mutated

Mutations add variety to speciesSome mutation are harmful, some are

beneficial

What disease is a result of a mutation?