1. CELLS Basic unit of life (except virus)
Prokaryotic, w/o nucleus, bacteria
Eukaryotic, w/ nucleus
Various cell types specialized for particular function. Differentiation.
Over 200 human cell types

3. Cells 56% of body is fluid Similar to sea water
Intracellular & extracellular
Exchange regulated by cell membrane (plasma membrane)
Passive transport (with gradient)
Active transport (requires energy)

4. Cells
Cell life supported by extracellular fluid containing: Ions: Calcium, Potassium, Sodium, … Nutrients: Glucose, Oxygen, Amino Acids, Vitamins, ... Regulatory chemicals: Steroids, Hormones, Paracrin/Autocrin factors, ...

5. Biochemistry Monomer Polymer Nucleic Acid Amino Acid Fatty Acid Sugar
RNA, DNA
Peptide, Protein
Lipid
Polysaccharide, Carbohydrate
Genes
Gene products
Not coded by genes

6. Biochemistry
Molecules or molecular regions (domains) are hydrophilic/hydrophobic
Water is polar (+ and - charged sides)
Charged and polar molecules are soluble in water
Nonionic, nonpolar molecules are insoluble in water

7. Fig 1

8. Biochemistry
C-C and C-H (hydrocarbons) bonds are nonpolar & hydrophobic
In water, hydrophobic molecules and nonpolar regions of molecules aggregate to “hide” from water

9. Biochemistry Amino Acid H O H2N C C OH Carboxyl Amino R
Side Chain (20)

10. Biochemistry Biochemistry H O H O H2N C C OH H2N C C OH R R +H2O H O H
Amino end N-Terminus
Carboxyl end
C-Terminus R R

11. Biochemistry Enzymes - Catalyze reactions (not metabolized).
All enzymes are proteins, but not all protein are enzymes.
“Structural” proteins provide physical rather than chemical function.

12. Cells
Cellular substructures called organelles made from membranes with similar structure floating in cytoplasm
Membranes consist of bi-layer of phospholipid.

13. Membranes Phosphate rich protein head Charged - hydrophilic Lipid tail
Hydrophobic

15. Membranes 2D Fluid, “oil slick”
Semipermeable depending on size & charge
Suspended proteins “float” in membranes. Hydrophobic regions w/in membrane, hydrophilic regions exposed
Ion channels, pumps, transporters, exchangers, receptors

19. Organelles Endoplasmic Reticulum, smooth & rough
SER - Site of lipid metabolism
RER - Contiguous with outer nuclear membrane. Site of protein synthesis (translation), storage, post-translational modification, sorting, and transport. Many tubular and vesicular membranes.

20. Organelles Ribosomes - Contained in RER
Responsible for translation of mRNA into protein.
Made up of protein and specialized structural RNA called ribosomal RNA (rRNA)

21. Organelles
Golgi Complex - Specialized portion of RER. Storage and sorting of protein vesicles prior to transport to membrane & secretion.

22. Organelles
Mitochondria - “Engines” of the cell. Convert glucose to ATP. Number in the hundreds to thousands. Contain own DNA.

23. Organelles
Lysosome - Lytic enzymes breakdown organic compounds and are sequestered lysosomes from rest of cell for protection. Proteins  Amino Acids Carbohydrates  Sugars

24. Cytoskeleton
Give cell structure, motility, intracellular vesicular trafficking, and ability to replicate.
Microfiliments 7-9nm
Intermediate filiments 10nm
Microtubules 24nm

25. Cytoskeleton Monomer Role Motor
MF Actin Stiffen plasma membrane Myosin
Provides motility by
depolymerizing & A-M
interaction
IF Vimentin Strictly structural None
Keratins One end attached membrane
Others Integrates cells w/ other cells
and into tissues
MT Tubulin “Track” for vesicle transport Dynein
Cilia and flagella motion Kinesin
Alignment/separation
of chromosomes

28. Organelles
Nucleus - Repository of DNA. Site of RNA synthesis (translation). Double membrane, outer continuous with RER. Large channels for export of mRNA to cytoplasm. Nuclear matrix proteins give nucleus structure.
Nucleolus - Large nuclear organelle where rRNA is synthesized and coupled with protein to form partial ribosomes.

31. Protein Synthesis
RNA polymerase bind to gene promoter and converts DNA to complementary mRNA (transcription). Binding to promoter regulated by transcription factors.
Non-coding mRNA is cleaved. Alternative splicing. Export of “mature” mRNA to ER
Ribosome converts mRNA sequence to AA sequence by attaching tRNA+AA subunits in groups of three mRNA bases (codons).

32. Protein Synthesis
Multiple ribosomes may be translating each mRNA over time or simultaneously
This cannot occur for rRNA, so 80%-90% of DNA codes for rRNA.
Post-translational modification - addition of lipids & carbohydrates, assembly of subunits. Intracellular and extracellular.

33. Ribosome (rRNA+Protein) ER
Translation AA AA AA AA AA
tRNA C U A G C T G U A G A C C G U C A U C U G G A U
mRNA
Ribosome (rRNA+Protein) ER
Nucleus
Transcription
Export
RNA
Polymerase
mRNA C G U C A U C U G G A G C A G T A G A C C T G G G G C
DNA