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The molecule of life, proteins and heredity.  DNA is a complex macromolecule that contains the genetic information that act as blueprints for making.

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Presentation on theme: "The molecule of life, proteins and heredity.  DNA is a complex macromolecule that contains the genetic information that act as blueprints for making."— Presentation transcript:

1 The molecule of life, proteins and heredity

2  DNA is a complex macromolecule that contains the genetic information that act as blueprints for making all the components of a cell  It contains the complete instructions for making all the proteins for an organism  Every part of an organism contains proteins, and their shape and functions determine what an organism looks like, what actions it does, what it can eat, even how it thinks!

3  Acts as a long-term storage molecule for information that codes all organisms  DNA is composed of long strings of nucleotides bound together  A Nucleotide has 3 parts ▪ 1. A simple sugar (deoxyribose) ▪ 2. A phosphate group ▪ 3. A nitrogenous base

4  There are 4 different nitrogenous bases that found in DNA:  1. Adenine (A)  2. Guanine (G)  3. Thymine (T)  4. Cytosine (C)  All the information of DNA is stored in the pattern of these bases in the DNA strand

5  DNA bases pair up with each other, this leads to 2 complementing strands  Adenine bonds to Thymine (A-T)  Guanine bonds to Cytosine (G-C)

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7  The long strands of nucleotides pairing with each other lead to a ladder like structure called a double helix The nitrogen bases form the zipper like middle and the phosphate/sugar group of the nucleotide serve as the backbone

8  If you break down any organism to its DNA they all have the same bases of A, T, G and C.  However the order these bases are arranged in is what separates snails from frogs and from humans etc.  Humans have just over 3 billion base pairs!

9  DNA is replicated during interphase before mitosis and meiosis  Is it important that the DNA that is replicated is identical?

10  Starts when the 2 strands of DNA separate  Each strand serves as a template for incoming bases  Since A only pairs with T and G only pairs with C

11  So nucleotide bases will come in and pair with the appropriate counterpart and begin forming 2 strands of identical DNA

12 There are Many enzymes which allow for DNA replication 1. DNA Polymerase 2. Helicase 3. Primase 4. DNA ligase

13  This enzyme is what finds and attaches the complementary base to the forming strand of DNA  It can only attach bases in a 5’ to 3’ direction

14  Because DNA polymerase can only add bases in a 5’ to 3’ direction it forms both leading and lagging strands  The leading strand can start and continue along as the DNA is unwound  The lagging strand must replicate in chunks, called okazaki fragments, because the DNA polymerase must run in the opposite direction of the unwinding

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16  DNA polymerase is extremely accurate, however it does also fix mistakes to increase the fidelity of DNA  This means that DNA replication is extremely accurate!

17  This enzyme is responsible for opening up the strands of DNA to allow replication to begin

18  Is an enzyme that binds initially to allow DNA polymerase to bind the strand and begin matching base pairs

19  Is an enzyme that comes in and seals the nicks left in the lagging strand

20  Complete the complementary strand of DNA if the template strand is ATTCGTTCGTAGC


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