disaccharides = two mono-s linked together e.g. lactose = glucose + galactose sucrose = glucose + fructose

Transcription

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2 involved in the degradation of molecules found in animal cells membrane limited varies in shape and size contains acid hydrolases (phosphatase, nucleases, proteases, etc.), enzymes that work only at acid ph levels acid ph level maintained through H+ pumps if contents spill into the cytosol no degradation takes place (ph in [ ]) it degrades membranes and organelles that have outlived their usefulness it plays role in the degradation of extracellular macromolecules (endocytosis: exterior -> cell) Tay-Sachs disease: inherited, recessive neurodegenerative disease, leads to death by age 5 defective lysosome is missing an enzyme (b-n-hexosaminidase-a) needed to degrade continuously accumulating constituent of plasma membrane of mamalian cells (particularly nerve cells)

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4 general formula: [ CH(OH) ] n disaccharides = two mono-s linked together e.g. lactose = glucose + galactose sucrose = glucose + fructose O C n H 2n+1 - C - H aldehyde or O C n H 2n+1 - C - C m H 2m+1 ketone and two or more hydroxyl groups

5 biomembranes separate a cell from its surroundings lipids are the structural elements of biomembranes fatty acids are the principal components of lipids general formulas for acids: O C n H 2n+1 - C - OH saturated O C n H 2n-1 - C - OH unsat. / single double bond O C n H 2n-3 - C - OH unsat. / 2 double-1 triple

6 O ffaattyy aaccyyll - C - O - CH2 O ffaattyy aaccyyll - C - O - CH O O ffaattyy aaccyyll - C - O - CH2 O ffaattyy aaccyyll - C - O - CH O CH2 - O - P - O- O- CH2 - O - P - O- O- O ffaattyy aaccyyll - C - O - CH2 O ffaattyy aaccyyll - C - O - CH O CH2 - O - P - O- O- O ffaattyy aaccyyll - C - O - CH2 O ffaattyy aaccyyll - C - O - CH O O ffaattyy aaccyyll - C - O - CH2 O ffaattyy aaccyyll - C - O - CH CH2 - O - P - O- O- O CH2 - O - P - O- O- O ffaattyy aaccyyll - C - O - CH2 O ffaattyy aaccyyll - C - O - CH O CH2 - O - P - O- O-

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8 H O NH 2 - C a - C - OH R POLAR: uncharged (=S, T, Q, N), + charged (=K, R, H), - charged (= D, E) HYDROPHOBIC: I, L, M, V, F, A, Y, W OTHER: C (=SH allows for disulphide bond) G (=small) P (=rigid)

9 H O H O NH 2 - C a - C - OH + HNH - C a - C - OH ---> R R H O H O N-terminus NH 2 - C a - C - NH - C a - C - OH + H 2 O C-terminus R R peptide bond

10 Figure from: Molecular Cell Biology 2nd edition Darnell/LodishBaltimore pp47

11 Proteins that catalyze chemical reaction Mediators of dynamic events. Enzymes increase the rates of reactions. Naming convention: XXX - ase is the name of the enzyme acting on molecule XXX Examples: XXX = protein -> protease XXX = rna -> ribonuclease XXX = dna -> deoxyribonuclease

12 produced after invasion by infectious agent(s) the recognition site of an antibody can bind tightly to very specific sites (generally on surface proteins or carbohydrates of the infectious agent) experimentally, animals will produce antibodies for any foreign injected polymer they act as signals for the elimination of infectious agents they have exquisite specificity composed of 2 heavy and 2 light chains; the N-termini of heavy/light chains are highly variable also useful in isolating proteins from a mixture

13 Figure from: Copyright: by Alberts, Bray, Johnson, Lewis, Raff, Roberts, Walter. Published by Garland Publishing, a member of the Taylor & Francis Group.

14 replication reverse transcription DNA RNA protein transcription translation replication

15 template strand 3' 5' 5' 3'

16 3' template strand EXON EXON EXON EXON 5' 5' 3' INTRON INTRON INTRON Gene Length #introns introns as % length Insulin 1.4 Kb 2 67 Serum albumin 18 Kb Cystic Fibrosis 250 Kb Dystrophin 2.3 Mb >100 99

17 Figure from: Artist: Darryl Leja

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19 3' 5' 5' 3' gene clusters same gene / different genes gene discontinuity introns / exons

20 3' 5' 5' 3' 3' 5' 5' 3' 5' 3' 5' 3' 3' 5' 5' 3'

21 Gene

22 -25 Gene TF IID TF IIB TF IID TF IIB TF IID E F TF IIB TF IID TF IIA TF IIA TF IIA TF IIA

23 5' GENE 3' start end "!

24 #"! & 9 / = >= C B A %A - % $ * 1 : & - ( ( ). -, + * &'() ) ( -; < -; < -;? % % %? % B A %

25 50s 60s 5s 23s 5s 5.8s 28s 34 polypeptides 49 polypeptides 30s 21 polypeptides 16s 33 polypeptides 18s 40s Prokaryotes Eukaryotes

26 DNA mrna RNA polymerase Protein

27 mrna RNA polymerase Protein DNA

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29 # *) & / 2 $! % ".-,+ ( ' %

30 #!! " 7 / 1 - / - 9 > : # #! #! #! #!! #! #! Σ # +* ) %#&'( ##$ #!!, <;,70 7:1 0, / , :..4 > = 90 : 9. 7= , A 1 / 4 :8 / 9: / HG F- 9AE 1 / 4 CD8:.4-0 / 4 BA,4

31 Σall i

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33 %

34 -3 0 E 4 : 8 = > 1 B,? 9 3? 9 H, 9 : - / H5, 9 H 9 / 8, > 9 3 / / / E 1, 3 / 9 1 4, 9 8 > 4 : /. -0 / 4 BA,4 9 / G A 02? : /. 04? A:? / 2 0A 9 / 04 B01 -> 3: 8 / 4: : 9 9.4? B A: 1,-0 :4A 9A :4 8 9A 4, : 34 8 / 4A := 9B 8 9A 4, : > :. 0 / A: / 4A := 9B 8 9A 4 >. 8 / : / 4 2 = 9B 8 3 A / 4. 9A A 9. 4? -,40 G C 8 G > - 9A 90 / 2 0 -,A / G 4 - / / 4 0A :1-0? / 2. > 4, / 40

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36 Ω A B Reality Algorithm - positives: A - true positives: A - negatives: Ω A sensitivity: B A B / A - false positives: B \ A - false negatives: A \ A specificity: A B B B / B