In this lecture you will learn:
DNA (Deoxyribonucleic acid) is made form 3 basic units:
SUGARS (backbone) note different sugars in DNA and RNA
|BASES (coding) note 1 different base in RNA than in DNA|
|When each unit is assembled it is called
This one is ATP (adenosine triphosphate)
The sugars and phosphates are in the backbone which then winds around in a double helix due to the angles of the chemical bonds
The bases are attached to the sugars and "stick out" from the backbone to the INSIDE of the double helix
|The bases hydrogen
bond with each other to form "BASE PAIRS". There are two rules:
1. A single ring only bonds with a double.
This maintains a uniform spacing within the double helix.
2. A base that needs 3 hydrogen bond can only bond with another base that needs 3 hydrogen bonds, the same is true for those that use 2 hydrogen bonds.
A only bonds with T
Hydrogen bonds are weak individually, but
strong collectively. The hydrogen bonds are protective of the DNA
bases but the closed DNA can be opened easily by enzymes, like helicase.
NOW GO WATCH THE MOVIE
FUNCTION of DNA
DNA is the master copy of all the genes
that build and run each cell. Every cell in the body has its own
copy of DNA. When it is time for a cell to split into daughter cells,
a new copy of DNA must first be made and that process of duplicating the
DNA is called REPLICATION
What is the function of DNA?
What are the three components of DNA?
Which components form the backbone of DNA?
Which component forms the rungs of the ladder?
What holds the rungs of the ladder together?
What are the two rules of DNA pairs?
Which of the following bond with each other and why?
A = adenine
C = cytosine
G = guanine
T = thymine
Be sure to know the parts of DNA on sight.