DNA Basics

1
DNA Basics

• Michael A. Johnson
• Scott Robison

2
Cell Nucleus

• Nucleus - Location of the chromosomes in the
  eukaryote cell
• Has a double semi-permeable membrane designed to
  keep DNA in check.

3
Chromosomes

• Chromosomes organized pockets of DNA that is
  comprised of chromatin.
• Chromatin complex of DNA tightly coiled around
  proteins.

4
Genes

• Genes sequence of specialized DNA that codes
  for specific amino acids to form one protein.
• There may be thousands of genes per chromosome
  pair in both plant and animals.

5
Viruses

• Viruses are not cells but, they are important to
  understand in the context of DNA and cells.
• Viruses parasites that enters cells and uses
  compounds in the cell to replicate. Viruses
  consist of DNA or RNA surrounded by a protein
  coat.

6
Viruses

• Viruses can not live or reproduce on their own.
  They must use their host for these basic
  processes.
• They are much smaller and simpler than bacteria.
• They contain little more than the information
  needed to assemble more viruses.

BV Virus
7
Viruses

• Viruses can be useful in that
• When they attack bacteria, the bacteria produces
  a restriction enzyme as a chemical defense.
  These enzymes cleave DNA making it more difficult
  for the virus to reproduce.

Foot and Mouth Disease
8
Viruses

• Viruses can be useful in that
• Scientists can insert useful foreign DNA into the
  virus, so when it attacks plants the plant will
  produce more virus and the desirable useful
  compounds
• Dozens of pharmaceuticals have been produced this
  way.

http//www.alphavax.com/newalphavax/html/technolog
y.html
9
DNA Basics

• DNA is the genetic blueprint for all humans,
  plants and animals.
• Each person has a unique DNA profile, like a
  fingerprint.

10
DNA Basics

• An individuals DNA profile remains the same
  throughout life.
• Each persons DNA is the same
• in every in cell.
• DNA has a net negative charge

11
DNA Basics

• DNA varies from person to person. Only exception
  identical twins.
• DNA controls all activities inside the human,
  plant, or animal body.
• DNA controls all inheritable traits, hair eye
  color all through proteins

12
DNA Basics

• Two types of cells with DNA importance
• Diploid Cells - contain full pairs of chromosome
  pairs
• Humans 23
• Goldfish 45
• Haploid Cells - contain half of the chromosomes
  (also called sex
• cells)
• Humans 11 chromosomes

13
DNA Basics

• Half of an individuals DNA comes from the
  father, the other half from the mother.
• Only about a tenth of the DNA
• composes genes, the function
• of the remaining has not yet
• discovered

14
DNA Basics

• DNA - Deoxyribonucleic acid
• DNA consists of two strands that wrap around each
  other. Double Helix
• If the strands were tied end to
• end it would stretch more than 5ft
  and less than 1/2 inch wide

15
DNA Structure

• DNA consists of three main parts
• Phosphorus backbone
• Deoxyribose sugar
• Nitrogen Bases

16
DNA Structure

• Nitrogen Bases
• Adenine (A)
• Thymine (T)
• Cytosine (C)
• Guanine (G)

17
DNA Structure

• Nitrogen Bases fit into one of two categories
• Purines
• Large, double ring structures
• Adenine Guanine
• Pyrimidines
• Small, single ring structures
• Cytosine Thymine

18
DNA Structure

• Base Pair Rules
• A purine always pairs with a pyrimidine
• Therefore
• A goes with T
• C goes with G

19
DNA Structure

• The order of the alphabet determines the
  characteristics of the living organism, much like
  the order of letters in our alphabet determines
  the words.
• Each cell in the human body contains gt3 BILLION
  letters.

20
DNA Facts

• In an average meal, you eat approximately
  55,000,000 cells or about 93,205 miles of DNA.

21
DNA Structure

• Nitrogen Bases are joined by weak Hydrogen Bonds
• very important to allow double strand to separate
  and recombine easily

22
Another way of looking at it...
23
Chromosomes

• Chromosomes - physical location of heredity that
  contains many long strands of DNA
• In humans they are arranged in 23 distinct
  chromosomes pairs

24
Karyotypes

• Karyotypes - a display of the chromosomes of a
  single cell. To obtain it, the cell is stained,
  then a picture is taken of it through a
  microscope just before cell division, when the
  chromosomes are easiest to see.

25
Karyotypes
26
Genes

• Each chromosome is comprised of genes.
• There may be as few as three or up to thousands
  of genes per chromosome.