B. Bruce - Central Dogma of Biology1

Possibly the earliest life used RNA:RNA can both store information and perform

enzymatic activities.

B. Bruce - Central Dogma of Biology2

Although early life probably used only RNA:Most life now uses DNA +

RNA + Proteins.

B. Bruce - Central Dogma of Biology3

The classic view of the central dogma of biology states:

"the coded genetic information hard-wired into DNA is transcribed into individual transportable cassettes,

composed of messenger RNA; each mRNA cassette contains the program for synthesis of a particular protein"

B. Bruce - Central Dogma of Biology4

The central dogma of biology is all about:Information Storage/Information Translation/

Information Conversion/Biological Action

Data storage/CDs/DNA

Printed information/Assembly Instructions/mRNA

Assembled Machine/Wheat Harvest/Protein

Biological Product/Food/Carbohydrate

Digital Printer/RNA Polymerase

Instructions to build/Ribosomes

Wheat Harvest/Enzyme Activity

Transcription Translation Protein Action

B. Bruce - Central Dogma of Biology5

DNA is folded into Chromosomes!

B. Bruce - Central Dogma of Biology6

Humans have 22 sets of chromosomes (from father and mother) plus Sex Chromosomes; XX or XY.

B. Bruce - Central Dogma of Biology7Figure 1-9 Essential Cell Biology (© Garland Science 2010)

Transcription goes from a stable 2-stranded DNA to a single stranded RNA

8Figure 7-2 Essential Cell Biology (© Garland Science 2010)

Having two steps allows much better control of the output, even amplification.

Lots of Protein A

Little of Protein A

B. Bruce - Central Dogma of Biology9

RNA Polymerases is a bio-machine that makes RNA from DNA- like a loom that makes cloth

from fiber.

B. Bruce - Central Dogma of Biology10

Nucleus

Organelles

Linear DNA

CellsCell membrane

ribosomes

nucleoid

circular DNA

Prokaryotes(bacteria)

Eukaryotes(plants and animals and fungi)

Structural differences between bacteria and eukaryotic cells

B. Bruce - Central Dogma of Biology11

Ribosomes are very big machines that assemble different amino acids together-

like different beads in jewelry.

B. Bruce - Central Dogma of Biology12

TEM of many Ribosomes making proteins from one mRNA

B. Bruce - Central Dogma of Biology13

Ribosomes make proteins; Proteins make Products; Enzymes are Catalyst

In chemistry. a substance that causes or accelerates a chemical reaction without itself being affected.

B. Bruce - Central Dogma of Biology14

Proteins start out unstructured- Like Origami. Then they FOLD into special shapes!

B. Bruce - Central Dogma of Biology15

Proteins shape gives them their activity!

B. Bruce - Central Dogma of Biology16

All the millions of proteins on earth are build from two secondary structures:

alpha-helix and Beta-sheet!