overview of bcor 11
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Overview of BCOR 11
(These are just some of the many themes we have talked about this semester.)
Structure and Function
Water1.1. Cohesion/surface tensionCohesion/surface tension2.2. Temperature moderationTemperature moderation3.3. Solvent AbilitySolvent Ability
• HydrophilicityHydrophilicity – dissolves – dissolves polar things & ionspolar things & ions
• HydrophobicityHydrophobicity – herds away – herds away nonpolar thingsnonpolar things
4.4. Ionization abilityIonization ability (pH) (pH)
H
Hydroniumion (H3O+)
H
Hydroxideion (OH–)
H
H
H
H
H
H
+ –
+Figure on p. 53 of water dissociating
Incr
easi
ngly
Aci
dic
[H+ ]
> [O
H– ]
Incr
easi
ngly
Bas
ic[H
+ ] <
[OH
– ]
Neutral[H+] = [OH–]
pH Scale
Figure 3.8
Various forms of Carbon molecules and functional
groups
CC
C
C
CC
HCCCCC=OO
N H
HH
HHHHH
HH
=C
Amino Acids and Proteins
LipidsCarbohydrates
monomers and polymers
Membrane Functions
3. transport
4. Signal detection
5. Cell-cellcommunication
2. Localize specific functions
1. boundaries6. Cell-cell
adhesion
A. Transport – channels and pumps
B. Links to structural proteins
C. Receptors - doorbells
D. Enzymes – localized biochemical rxns
E. Energy Generation – utilize gradient
Voltage Ligand Mechanosensitive
Proton pump
Sucrose-H+
cotransporter
Diffusionof H+
Sucrose
ATP H+H+
H+
H+
H+
H+
H+
++
+
+
++–
–
––
–
–
Rough ER Smooth ER
Centrosome
CYTOSKELETON
Microfilaments
Microtubules
Peroxisome
Lysosome
Golgi apparatus
Ribosomes
In animal cells but not plant cells:LysosomesCentriolesFlagella (in some plant sperm)
NUCLEUS
Intermediate filaments
ENDOPLASMIC RETICULUM (ER)
Mitochondrion
Plasma membrane
Figure 6.9
endoplasmic reticulumnucleus
mitochondrion lysosome
Golgi apparatus
cytosol
ribosomes
Animal CellAnimal Cell
Bacterial and Viruses
Storage and Transfer of Energy
GG = = HH - - TTSS
-
HOOH
HO
OH
+
HOOH
Enzymes bring substrates together to lower the activation energy of a reaction
Free
ene
rgy
Progress of the reaction
∆G < O
EA
Figure 8.14
A BC D
Reactants
AC D
B
Transition state
A BC D
Products
LIGHTREACTOR
NADP+
ADP
ATP
NADPH
CALVINCYCLE
[CH2O] (sugar)STROMA(Low H+ concentration) Photosystem II
LIGHTH2O CO2
Cytochromecomplex
O2
H2O O21
1⁄2
2
Photosystem ILight
THYLAKOID SPACE(High H+ concentration)
STROMA(Low H+ concentration)
Thylakoidmembrane
ATPsynthase
PqPc
Fd
NADP+
reductase
NADPH + H+
NADP+ + 2H+
ToCalvincycle
ADP
PATP
3
H+
2 H++2 H+
2 H+
Figure 10.17
Proton gradients power reactions to create high energy
ATP
NADPHNADPH and ATPATPcan be used to can be used to transfer transfer energyenergy
Fatty Acid Oxidation (Fatty Acid Oxidation (-oxidation) -oxidation)
Energy is captured in many small steps in this metabolic pathway
-captures Reducing potential NADH + H+
FADH2
Saturatedhydrocarbon
unsaturatedhydrocarbon
2e-2 H+removed
alcoholKetone2e-
2 H+removed
Ester(acid)
PrimingStep
Signaling, Information transfer, and feedback
loops
TRANSCRIPTION RNA is transcribedfrom a DNA template.
DNA
RNApolymerase
RNAtranscript
RNA PROCESSING In eukaryotes, theRNA transcript (pre-mRNA) is spliced andmodified to producemRNA, which movesfrom the nucleus to thecytoplasm.
Exon
Poly-A
RNA transcript(pre-mRNA)
Intron
NUCLEUSCap
FORMATION OFINITIATION COMPLEX
After leaving thenucleus, mRNA attachesto the ribosome.
CYTOPLASM
mRNA
Poly-A
Growingpolypeptide
Ribosomalsubunits
Cap
Aminoacyl-tRNAsynthetase
AminoacidtRNA
AMINO ACID ACTIVATION
Each amino acidattaches to its proper tRNAwith the help of a specificenzyme and ATP.
Activatedamino acid
TRANSLATION A succession of tRNAsadd their amino acids tothe polypeptide chainas the mRNA is movedthrough the ribosomeone codon at a time.(When completed, thepolypeptide is releasedfrom the ribosome.)
Anticodon
A CC
A A AUG GUU UA U G
UACE A
Ribosome
1
Poly-A
5
5
3
Codon
2
3 4
5
Information stored in DNA is used to build proteins
DNA
mRNA
polypeptide
DNA -> mRNA -> Protein
DNA structureSugar-phosphate
backboneNitrogenous
bases
5 endO–
O P O CH2
5
4O–
HH
OH
H
H3
1H O
CH3
N
O
NH
Thymine (T)
O
O P O
O–
CH2
HH
OH
HH
HN
N
N
H
NH
H
Adenine (A)
O
O P O
O–
CH2
HH
OH
HH
HH H
HN
NN
OCytosine (C)
O
O P O CH2
5
4O–
H
O
H
H3
1
OH2
H
N
NN H
ON
N HH
H H
Sugar (deoxyribose)3 end
Phosphate
Guanine (G)
DNA nucleotide
2
NC
T
A
A
T
CG
GC
A
C G
AT
AT
A T
TA
C
TA0.34 nm
3.4 nm
G
1 nm
G
T
Amino end Growing polypeptide
tRNA
mRNA
Codons
3
5
Ribosomes translate the RNA message into a polypeptide
Second mRNA baseU C A G
U
C
A
G
UUUUUCUUAUUG
CUUCUCCUACUG
AUUAUCAUAAUG
GUUGUCGUAGUG
Met orstart
Phe
Leu
Leu
lle
Val
UCUUCCUCAUCG
CCUCCCCCACCG
ACUACCACAACG
GCUGCCGCAGCG
Ser
Pro
Thr
Ala
UAUUAC
UGUUGC
Tyr Cys
CAUCACCAACAG
CGUCGCCGACGG
AAUAACAAAAAG
AGUAGCAGAAGG
GAUGACGAAGAG
GGUGGCGGAGGG
UGGUAAUAGStop
Stop UGAStopTrp
His
Gln
Asn
Lys
Asp
Arg
Ser
Arg
Gly
UCAGUCAGUCAGUCAG
Firs
t mR
NA
bas
e (5
end
)
Third
mR
NA
bas
e (3
end
)
Glu
• Mitosis produces an exact copy of the parent cell. – Used for growth and asexual reproduction.
• Meiosis produces reduced (haploid) gametes, which are genetically unique.– Necessary for sexual reproduction.
Meiosis generates variation through:- independent assortment of chromosomes- crossing over
Mitosis vs Meiosis
Homologs pair in meiosis 1
Sister chromatids separate in meiosis 2
haploid
Not paired diploid
Information must be copied exactly eqch time a cell divides
DNA replication machine
DNA sequences are determined by “poisoning” a synthesis reaction with dideoxy nuclotides
PCR is just repeated cycles of DNA synthesis in a test tube
DNA is always synthesized 5’ to 3’
Cells detect signal & respond
Signal transduction pathways AMPLIFY the signal
1º messenger
2º messengers
EffectorEnzymes Target
Enzymes
Genes of operon
Protein
Operator
Polypeptides that make upenzymes for tryptophan synthesis
Regulatorygene
RNA polymerase
Promoter
trp operon
5
3mRNA
trpDtrpE trpC trpB trpAtrpRDNA
mRNA
E D C B A
The trp operon: regulated synthesis of repressible enzymes
Figure 18.21a
5
Tryptophan absent -> repressor inactive -> operon “on”
Cell type–specific transcriptionEnhancer Promoter
Controlelements
Albumin gene
Crystallin gene
Liver cellnucleus
Lens cellnucleus
Albumin geneexpressed
Albumin gene not expressed
Crystallin genenot expressed
Crystallin geneexpressed
Liver cell Lens cell
Fig 19.7
All cells have the same genes, but only certain genes are expressed in each tissue
Different set of activator proteins in the two cell types
Cell Cycle Regulators and Cancer
Thank you!
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