glucose (a) linear and ring forms(b) abbreviated ring structure
TRANSCRIPT
Glucose
(a) Linear and ring forms (b) Abbreviated ring structure
Disaccharides
(b) Dehydration reaction in the synthesis of sucrose
Glucose Fructose Sucrose
MaltoseGlucoseGlucose
(a) Dehydration reaction in the synthesis of maltose
Different Ring Strucutres
(a) and glucose ring structures
Glucose Glucose
and Configurations
Cellulose
Glucosemonomer
Cellulosemolecules
Microfibril
Cellulosemicrofibrilsin a plantcell wall
0.5 µm
10 µm
Cell walls
Chitin
The structureof the chitinmonomer.
(a) (b) (c)Chitin forms theexoskeleton ofarthropods.
Chitin is used to makea strong and flexiblesurgical thread.
Fats (Triacylglycerols)
Fatty acid(palmitic acid)
(a) Dehydration reaction in the synthesis of a fat
Glycerol
Saturated Fats
(a) Saturated fat
Structuralformula of asaturated fatmolecule
Stearic acid, asaturated fattyacid
Unsaturated Fats
(b)Unsaturated fat
Structural formulaof an unsaturatedfat molecule
Oleic acid, anunsaturatedfatty acid
cis doublebond causesbending
Phospholipids
(b)Space-filling model(a) (c)Structural formula Phospholipid symbol
Fatty acids
Hydrophilichead
Hydrophobictails
Choline
Phosphate
Glycerol
Hyd
rop
ho
bic
tai
lsH
ydro
ph
ilic
hea
d
Fig. 5-14
Hydrophilichead
Hydrophobictail WATER
WATER
Steroids
Fig. 5-16
Enzyme(sucrase)
Substrate(sucrose)
Fructose
Glucose
OH
H O
H2O
Fig. 5-UN1
Aminogroup
Carboxylgroup
α carbon
Amino Acids
Amino Acids
Peptide Bond
Sickle-cell Disease
Secondary Structure
Tertiary Structure
Quaternary Structure
4 Levels of Protein Structure
What determines a proteins structure?
The unique conformation endows each protein with a specific function
Physical and chemical environment affects struture- _________________: protein unravels and losses its conformation
- pH, [salt], temperature
Protein Folding in the Cell
It is hard to predict a protein’s structure from its primary structure
Go through several intermediate structures
____________ are protein molecules that assist the proper folding of other proteins
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 5-24
Hollowcylinder
Cap
Chaperonin(fully assembled)
Polypeptide
Steps of ChaperoninAction:
An unfolded poly-peptide enters thecylinder from one end.
1
2 3The cap attaches, causing thecylinder to change shape insuch a way that it creates ahydrophilic environment forthe folding of the polypeptide.
The cap comesoff, and the properlyfolded protein isreleased.
Correctlyfoldedprotein
DNA, RNA and Proteins
mRNA
Synthesis ofmRNA in thenucleus
DNA
NUCLEUS
mRNA
CYTOPLASM
Movement ofmRNA into cytoplasmvia nuclear pore
Ribosome
AminoacidsPolypeptide
Synthesisof protein
1
2
3
Fig. 5-27ab5' end
5'C
3'C
5'C
3'C
3' end
(a) Polynucleotide, or nucleic acid
(b) Nucleotide
Nucleoside
Nitrogenousbase
3'C
5'C
Phosphategroup Sugar
(pentose)
Fig. 5-27c-1
(c) Nucleoside components: nitrogenous bases
Purines
Guanine (G)Adenine (A)
Cytosine (C)Thymine (T, in DNA)Uracil (U, in RNA)
Nitrogenous bases
Pyrimidines
Fig. 5-27c-2
Ribose (in RNA)Deoxyribose (in DNA)
Sugars
(c) Nucleoside components: sugars
Fig. 5-27ab5' end
5'C
3'C
5'C
3'C
3' end
(a) Polynucleotide, or nucleic acid
(b) Nucleotide
Nucleoside
Nitrogenousbase
3'C
5'C
Phosphategroup Sugar
(pentose)
Fig. 5-28
Sugar-phosphatebackbones
3' end
3' end
3' end
3' end
5' end
5' end
5' end
5' end
Base pair (joined byhydrogen bonding)
Old strands
Newstrands
Nucleotideabout to beadded to anew strand
DNA and Proteins as Tape Measures of Evolution
Siblings share similarity in DNA and protein sequences than unrelated species members
Two species that appear closely related based on fossil and anatomical evidence should more similar in DNA sequences than more distantly related species
Molecular biology can be used to assess evolutionary kinship
You should now be able to:
1. List and describe the four major classes of molecules
2. Describe the formation of a glycosidic linkage and distinguish between monosaccharides, disaccharides, and polysaccharides
3. Distinguish between saturated and unsaturated fats and between cis and trans fat molecules
4. Describe the four levels of protein structure
You should now be able to:
5. Distinguish between the following pairs: pyrimidine and purine, nucleotide and nucleoside, ribose and deoxyribose, the 5 end and 3 end of a nucleotide