Kategorier: Alle - division - rna - regulation - proteins

av Ron Chertakovsky 7 år siden

129

Biology Extra Credit

Cells exhibit a high degree of functional and structural complexity, influenced by various mechanisms and components. Key to cellular operation are enzymes like RNA polymerases and DNA polymerases, which drive transcription and replication.

Biology Extra Credit

RON C.

Activator or Repressor Proteins

RNA POL I,III

DNA POL III & I

Proteins Mediate Function

Histone core

potentially prevents condensing

Protein-Protein Interactions

Recognition
Cyclin-CDK Recognition

Regulates whether or not M phase occurrs

Allows for S phase to proceed

Carrier/Channel Proteins

Signal Transduction Pathway

Possible transcription factor cellular response post Signal Transduction Pathway

Ligand- Gated Ion Channel Receptor
Ligand- RTK Receptor
Ligand- G Protein Coupled Receptor

Enzymes: tertiary structure + Active Site exposed R groups

Allosteric?
Enzyme becomes more specific
One Active Subunit activates ALL close proximity subunit active sites
Photosynthetic Efficiency
Positioning of primary e- acceptor

right next to highly energetic a pair e- result: maximizing oxidative power

Light harvesting complex

Phostosystems are Integral Proteins!

Integrins facilitate ECM>cytoplasm contact

pigment molecules positioned in a cluster maximize e- energy release in order to truly excite P680/700 of reaction complex

photosynthetic chemiosmosis

Stroma>Thylakoid space>Stroma direction of ATP formation

ATP deposited where needed the most by stroma occurring Calvin Cycle

Metalloenzyme Breaking H20

constant supply of e- to PSII

PEP Carboxylase's exclusive CO2 Affinity

minimizing photorespiration

movement

motor protein
kinetochore movement

kinetochore microtubule + motor protein separation of homologs & chromatids

kinetochore microtubule + motor protein separation of chromatids

microtubule + cytoplasmic dynein = lysosomal movement to fuse w/ plasma mem for exocytosis

Structure affects function & vice versa

Cell Compartmentalization = Increased Complexity/Specifity

Photosynthesis
Uncoupled Transcription/Translation
transcription @ Nucleus
translation @ Cytoplasm

All Genetic Information is expressed/transferred in a Regulated Manner

Cell Division

Meiotic Division: Result= haploid division of germ cells

Mitotic division: Result= diploid division of somatic cells

eukaryotic regulation

transcription factor-control sequence

eukaryotic coordinated control

Parallels to

chromatin folding @ nucleus

prokaryotic regulation

prokaryotic operon

plenty of space for 1. alternative splicing 2. polyribozymatic translation

Cristae folds
maximize space for # of ETC per mitochondria
lysosomes
risky acidic pH environment kept away from cell interior