(beans)
Monocots Eudicots (grasses)
2 1 seed leaf (cotyledons)
seed leaves (cotyledons)
MM ultiple of 3 flower partsStudy Guide:
ultiple of 4 or Chapter 12
5 flower parts
Branched root
Fibrous root
Pollenpore or slit or then
One replicated
Central Dogma: DNA ishas 3 poresandslits transcribed to RNA, which is translated to
protein.
the main purpose of genetic material is to encode the production of
proteins in the correct cell, at the proper time, and in suitable amounts.
Structural genes encode the information for specific proteins
Transcription:
* rate of transcription depends on the affinity of polymerase to the promoter.
1. Initiation
1. Sigma factor binds to RNA polymerase
2. Complex (RNA Polymerase) binds to promoter
3. DNA strands unwind = open complex
2. Elongation
4. Sigma factor released
5. RNA polymerase synthesizes RNA
a. Synthesizes the complimentary single strand RNA in 3 direction
b. Uracil substituted for thymine
c. Open complex 10-15 bp
3. Termination
6. RNA polymerase reaches termination sequence
7. RNA polymerase and newly made RNA transcript dissociates from RNA.
Eukaryotes and Prokaryotes:
-
Promotor
-
RNA poly merase
-
Transcription factors
In Eukaryotes,
- p ro motor more complex,
- m ore poly merases and factors,
- a nd RNA extensively processed.
- -Capping 5 end
--Splicing (re moval of introns and ligation of exons) spliceosome
- -Polyadenylation of 3 end. (Poly A Tail)
Introns m ust be re moved with spliceosome before translation happens.
o Poly A tail keeps the message stable
o 5 cap- protects the message
Translation:
3 nucleotides = 1 codon
-61 codons specify a mino acid
- 1 start codon (AUG)
-3 stop codons
Reading Frame: defined by start codon- read in groups of three until -stop codon
Every message has untranslated region near 3 end and 5 end
Major Players:
1 . mRNA contains the code for the polypeptide sequence
2. tRNA has anticodon and proper amino acid attached to it
3. Ribosomes location where mRNA and tRNA can properly interact with each other
( 30s + 50s = 70s)
4. Translation Factors
1 . Bind Ribosome 30 s AUG
tRNA (charged tRNA in p site)
50s
2. P site peptidyl site
A Site aminoacyl site
E Site exit site
Peptidyl transfer reaction- amino acid transfers from P site to A site tRNA rRNA
catalyzed the peptide bond formation
3. Release factor in A site
Eukaryote Scanning to start binding site
Chapter 13: Gene Regulation
Constitutive Genes: always turned on
Regulated Genes: Sometimes expressed, sometimes not. Turned on or off for energy
conservation expression level varies
Physiology: genes can be turned on or off
Mechanism how that happens
Negative Control: promotor binds to turn gene off inhibits something
Positive Control Promotor activates
Genes organized into operons = regulatory region of DNA
Lac operon
If lactose is not present, repressor will bind to Lac O
IF lactose is present-which forms alloctose- it will inactivate the lac
repressor. will prevent it from binding to lac O and transcription can
happen. Negative control
If glucose is low, cAMP will be produced and bind with CAP protein at
CAP site. The bends DNA and allows transcription.
If glucose is high, cAMP will not be produced and nothing will bind to
CAP which site, prevents transcription.
In Eukaryotes:
Transctription Regulation:
-
Core pro motor: series of other ele ments called response elements
-
Promotor in Eukaryotes is larger and more co mplex and has m ore binding
s ites
1 . General Transcription Factors: Promotor and Regulatory Sequences
1. Regulatory transcription factors: activators and repressors
-Activators bind to enhancers
- Repressors binds to silencers
2. Regulatory sequence elements: enhancers and silencers
3 ways transcription factors bind to regulatory sequence elements:
1 . Bind to GTFs
2 . Bind to mediator
3. Recruit Proteins that influence DNA packaging
- modify histones or re model chro matin
2 . Alternative Splicing: use of different exons
3. RNA interference or mRNA silencing : MicroRNAs silence the expression of mRNAs
w idely found in plants and animals
-
Degrades RNA or inhibits translation
Translation: Iron binding protein binds to mRNA and does not allow ribosome to
t ranslate (eg. Ferritin)
Plants:
-
Alteration of Generations:
3 o rgans in plants:
1. Roots provide efficient anchorage in soil for the uptake of water and m inerals
2 . Stem produce leaves and branches and bare the reproductive structures
3 . Leaves flattened and specialized for photosynthesis
Each organ has 3 t ypes of tissues:
Vascular: xyle m (water) and phloem (organic ma terials)
Herbaceous Plants: Primary vascular tissue
Woody Plants: Primary and Secondary vascular as herbaceous plants)
(begin tissue
-Vascular Cambium: xylem to interior phloem to exterior
- Cork Cambrium produces cork cells dead when mature.
Dermal: Epidermis
Ground: Everything Else
Viruses and Bacteria:
Archaea: - l ike Eukaryotes because
1. DNA binding proteins
2. Transcription machinery
3. Translation Factors
Bacteria:
4 shapes:
1. Spheres (cocci)
2. Rods (bacilli)
3. Comma (vibrio)
4. Spiral (spirliia)
Gram Negative vs. Gram Positive
(+)= purple = thicker peptidoglygocan wall
(-) = pink= (LPS) lippopolysaccharides
Live in communities
o Biofilms community of one or more microbial groups
Can communicate through quorum sensing
4 steps of Microbial Infection: virulence factors
1. Adhesion capsule, pili, fimbriae, biofilms
2. Invasion
3. Colonization and Growth
-
nutrient availability:
o micronuteirnts tranferrir and aerobactin bind iron
o breakdown of cells : cell lysis
-
Enzymes tha t promote colonization
o Breakdown proteins, lipids, nucleic acids
o Break down collgen
o Dissolves fibrin
o Causes blood to clot
o
-
Temp
-
Oxygen Content
4 . Tissue Damage and Disease (Toxins)
- Exotoxins- secreted by cells
- cause da mage at a specific site
- B otulinu m b locks nereo signals for m uscles to relax
( difficult to breath because m uscles cant contract)
-Tetnus inhibits relaxation
Viruses: mall particles that consist of nucleic acids in a protein coat
S
- can have DNA or RNA
Structure:
- Envelope derived from host plasma me mbrane
- Genome DNA or RNA
- All viruses have outer capsid protein coat wi th nucleic acid inside.
- Require host cell
Steps of Viral Infection:
1 . Attach men t
2. Entry
3. Integration (Not Always)
4. Synthesis of viral components
5. Assembly
6. Release
- Endotoxins LPS of Gram negative
- c ause general symp to ms