DNA: the blueprint of life

Where do you get your DNA? DNA is passed from parent to offspring. Where do we find DNA? DNA is in the nucleus of every cell. DNA makes up our chromosomes. Humans have 46 (23 pairs).

What is DNA? DNA is the genetic code. DNA is called the “blueprint” for living things. What does the code “code for”? DNA codes for the building of PROTEINS. DNAProteinTraits Gene – enough DNA to make 1 protein

Important Note  All cells carry out protein synthesis, each making their own proteins.  Each organism makes its own specific proteins, those proteins make an organism different from other organisms.

The “NA” in DNA stands for ? Nucleic Acid Deoxyribonucleic Acid DNA

What is a nucleic acid? Nucleic acids may be polymers made up of chains of many nucleotides. What is a nucleotide? A three part unitcomposed of: A three part unit composed of: a sugar a phosphate a base Nucleic acids are made of nucleotides.

Nucleic acids are named for the type of sugar that they contain. DNA – Deoxyribose sugar RNA (which we will discuss later) – Ribose sugar Nucleic acids are named for the type of sugar that they contain. DNA – Deoxyribose sugar RNA (which we will discuss later) – Ribose sugar

DNA’s shape? A double helix It looks like a twisted ladder or spiral staircase or spiral staircase ** The structure of DNA was discovered by James Watson and Francis Crick

If DNA is compared to a twisted ladder, the sides of the ladder are... The rungs (or steps) are... sugars and phosphates the bases There are 4 bases...

4 Base Nucleotides Adenine - A Thymine – T Guanine - G Cytosine - C

Each base can only pair with one other base Adenine - A Thymine – T Guanine - G Cytosine - C

The base pairing is: AT C G Why? Bases will always pair this way because: Size (number of rings) Size (number of rings) Number of bonds Number of bonds *** The order of these bases codes for different proteins / traits.