DNA PART 1 THE BLUEPRINT OF LIFE DNA

DNA PART 1: THE BLUEPRINT OF LIFE

DNA – The Blueprint of life

How would you describe DNA ? ?

DNA stands for … Deoxyribo. Nucleic Acid

DNA Facts Establishes by James Watson and Francis Crick Spape of a double helix

Codes Made for your genes (traits) of repeating subunits called nucleotides Nucleotides are held together by Hydrogen bonds.

What is a nucleotide? Has three parts: 1. Deoxyribose (sugar) 2. Nitrogen base (A, T, G, C) 3. Phosphate Group

Base- Pair Rule Adenine – Thymine Guanine – Cytosine The sides of the DNA ladder are phosphate & sugar Held together by hydrogen bonds

Base Pair Rule One side: A T C A T G C G A G Other Side: _ _ _

What exactly is a Gene? ?

What exactly is a gene? A segment of DNA that codes for a protein, which in turn codes for a traits ( eye color, freckles, …) A gene is a stretch of DNA

How the Code Works The combination of A, T, G, C determines what traits you might have …. C A T = purple hair T A C T A G = yellow hair

Think of the bases of DNA like letters. Letters form words … Words form sentences … v Endless combinations

Let‘s Review What We Know About DNA 1. DNA stands for: De_______ribo_____ acid 2. What is the shape of DNA? _________ 3. Who established the structure of DNA? ________ and _______ 4. Adenine always pairs with ________ 5. Guanine always pairs with ________. 6. The sides of the DNA ladder are deoxyribose and __________.

7. What is the complementary sequence: C A T T A G 8. The two sides of DNA are held together by _____________ bonds. 9. DNA is composed of repeating subunits called ____________. 10. What are the 4 bases that make up the rugs of the DNA ladder? _____________________

Part 2: DNA Replication

DNA Replication The process by which DNA makes a copy of itself (cell division) Why does DNA need to copy? § Cells divide for an organism to grow, heal or reproduce, § every new cell needs a copy of the DNA or instructions to know how to be a cell. § DNA replicates right before cell division.

DNA Replication Enzyme Heliase opens the DNA molecule by breaking the Hydrogen bonds. DNA replication is semi-conservative: That means that half of the old strand is saved. § This helps to reduce errors. §

DNA Replication

Part 3: From DNA to making a Protein

RNA - messenger DNA stays in the nucleus, but in order for it to get its instructions translated into proteins, it must send a message The message is send to the Ribosome, where Proteins are made. The chemical used to carry the message is the messanger RNA § m. RNA

RNA - messenger RNA = ribonucleic acid RNA is similar to DNA except: 1. Has one single strand instead of two strands 2. Has Uracil instead of Thymine 3. Has Ribose instead of deoxyribose Follows base pair rule: A -> U DNA: A T A G C G RNA:

The Job of m. RNA: RNA carries the „message“ to the ribosome, where proteins are made

How does DNA make a protein?

DNA RNA Proteins (traits) are the building blocks of the organism

Transcription – process where RNA is made from DNA Translation – process where proteins are made from RNA

Let‘s draw …

DNA transcription

Part 4: How Proteins are made by the Cell This section thrives to answer the following question: What is a protein, how is it made and why is it important for living systems?

Your body is made up of trillions of cells, of all different kinds: muscle cells, brain cells, blood cells, and many more. Inside those cells, proteins are allowing our body to do what it does: v break down food to power your muscles, v send signals through your brain that control the body, v and transport nutrients through your blood. Proteins are building blocks they make up all that you are.

Transcription 1. One of the strands of DNA is used as a template to create a strand of m. RNA. 2. The enzyme RNA polymerase makes the m. RNA. 3. Transcription always starts at a region called the promoter.

4. 2 Sections of genes: Introns are segments of DNA that do not contain genes. • Exons are segments that contain genes. • 5. Each 3 bases on m. RNA make up a codon, it corresponds to an amino acid (see codon chart)

Translation 1. Takes the message on m. RNA and converts it into an amino acid chain 2. Individual amino acids will join to form a protein. Shapes and structure of the protein determine its function: (hair, enzymes, skin, muscles etc)

Let‘s draw ….

The steps in translation are: 1. 2. 3. 4. 5. The Ribosome binds to m. RNA. The Ribosome starts matching t. RNA anticodon sequences to the m. RNA codon sequence. Each time a new t. RNA comes into the Ribosome, the amino acid that it was carrying gets added to the growing protein chain. The Ribosome continues until it hits a stop sequence. The Protein chain forms into its assigned shape and starts acting as a functional protein in the cell.

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