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Reading notes quiz#1, answer 4 of 5:. does irradiating food add radiation to food? Explain Describe the “octet rule” What are the two types of chemical bonds List at least 3 important properties of water Biological molecules are grouped into four categories; list at least 3 of these four. - PowerPoint PPT Presentation
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Reading notes quiz#1, answer 4 of 5:
1. does irradiating food add radiation to food? Explain2. Describe the “octet rule”3. What are the two types of chemical bonds4. List at least 3 important properties of water5. Biological molecules are grouped into four categories; list at
least 3 of these four.
Reading Notes Quiz#2:Answer 3 of these 4 questions
1. Biological molecules are grouped into four categories. List 3 of these 4.
2. How do perms and relaxers work on hair?
3. Describe the difference between a monomer and a polymer; give an example of a monomer and a polymer (your example does not have to be a biomolecule).
4. Like all lipids, a triglyceride is insoluble in water because it lacks many fill in the blank functional groups. Triglycerides are used for fill in the blank and are made from two subunits, a single molecule of fill in the blank plus three molecules of fill in the blank.
HydrophobicHydrophilicFatty acidsGlycerolAmino acidGlycogenLong-term energy storageQuick and ready source of energyStoring genetic informationMaking a phospholipid membrane
What did this little piggy build his house with?
(why does he build it with that that stuff, and how does he build it?)
What do you get if you crack open a cell?
What: You are what you eat!the four classes of biomolecules
Nucleic acid (DNA, RNA)
Protein (amino acid)
Lipids (fat)
Carbohydrates (sugars)
Why build a cell with these materials?
What: Why (what is used for?):Lipids (fat) store energy (fats and oils)
build cell membranes (cholesterol & phospholipids)
cell to cell signaling (steroids)
Sugar (carbohydrates) build cell structures (cellulose), quick energy (glucose)
Protein build cell structures (microtubules)build cellular machines (enzymes)
Nucleic acid store genetic information (DNA)
How do you build a cell: Biomolecules are built using a
carbon scaffold + functional groups
Carbon scaffold (C and H)
Analogy: train cars
string of Christmas lights
Functional groups (O, N, P, S)
Analogy: Different cargo in each train car
Different colored light bulbs
monomer + monomer + monomer + monomer = polymer“Food” is a polymer, you tear it down into monomers a rebuild polymersAnalogy: tear down a house into 2x4’s, bricks, windows, and rebuild
Biomolecule #1Lipids - water insoluble hydrocarbons (C + H):
triglycerides (fats and oils)
phospholipids
cholesterol / steroids
What’s their structure? What are they made from?What’s their function?
One type of lipid: Triglycerides (fats and oils)
glycerol + fatty acid (sugar alcohol) + (hydrocarbon)
Why are hydrocarbons (like fatty acids) insoluble in water?
WHAT IS A TRIGLYCERIDE USED FOR?
Different types of fatty acids:Saturated: all bonds between carbon are single bonds
Unsaturated: some double bonds between carbons (therefore less Hydrogens)cis vs trans affects there physical property
Page 43, fig 3.13
Another type of lipid: Phospholipids
Phospholipids - p 44, fig 3.14
how are these different from triglycerides (fats and oils)?(what are they made from?)
What’s their function?
Another type of lipid: cholesterol & steroids
cholesterol & steroids - p 44, fig 3.15
how are these different from phospholipids and triglycerides?What are they made from?
how are they similar?
What’s their function?
Biomolecule #1Lipids - water insoluble hydrocarbons (C + H):
triglycerides (fats and oils) long term energy storage
phospholipids build cell membranes
cholesterol / steroids building cell membranes & signaling between cells
Lipids are insoluble in water because they are built from hydrocarbons, and hydrocarbons are hydrophobic because they do not have any functional groups that form hydrogen bonds with water.
Why is a water-insoluble molecule good for: storing energy, orbuilding cell membranes, orsignaling between cells?
Biomolecule #2Carbohydrates (sugars) - Carbon + H2O:
monomers: glucose, fructose, galactoseglycerolribose, deoxyribose
polymers:Disaccharides (lactose, maltose)starchglycogenCelluloseChitin
Carbohydrates monomers
carbohydrates polymers: various usesstarch, glycogen, cellulose
chitin (glucose + NH2, amino functional group
Biomolecule #2Carbohydrates (sugars) - Carbon + H2O:
monomers: function:glucose, fructose, galactose quick energy sourceglycerol build triglyceridesribose, deoxyribose build DNA, and RNA
polymers: function:Disaccharides (lactose, maltose) quick energy sourcestarch energy storage (plants)glycogen energy storage (muscle)Cellulose build structuresChitin build structures
Biomolecule #3Proteins - modified carbon skeleton backbone:
backbone is amino + carbon + carboxylic acid,plus many diverse functional groups
monomers:amino acids
polymers: peptides/proteins enzymesMicrotubulesHemoglobinMembrane proteins
Protein monomer is amino acid.amino acids have modified carbon skeleton backbone:
amino + carbon + carboxylic acid,plus many diverse functional groups
Amino Acid Functional Groups:
Proteins are the most versatile biomolecules because they are made from chemically diverse monomers (amino acids with many different functional groups)
A protein (or peptide) is a polymer made from amino acids
Biomolecule #3Proteins -
…but what does a protein do?
Just about everything!
polymers: peptides/proteins function:enzymes “machine” / metabolismMicrotubules used to build structures Hemoglobin used to transport other moleculesMembrane proteins selective doorway into cell
What’s an enzyme? What do I mean by “cellular machine”?
Enzymes are “machines” that enable certain bonds to form or break faster than they would without the enzyme
How do machines work?Shape determines function
Cup
Spoon
Hammer
knife
How does a Protein do its function? It folds into a particular shape.
Primary structure: String of amino acids
Secondary structure: Backbone H-bonds with self, making helix or sheet
Tertiary structure: Functional groups determines shape
shape determines function/activity
ADH (Alcohol DeHydrogenase) protein structure
QuickTime™ and a decompressor
are needed to see this picture.
Proteins can unfold (denature)
Too hot
Too acidic or too basic
Biomolecule #4:Nucleic acids nitrogen-containing “base”
+ sugar (ribose or deoxyribose)+ phosphate
Monomer (nucleotide bases): function:A (Adenine) energy “currency”T (Thymine) and U (Uracil)G (Guanine)C (Cytosine)
Polymer: function:DNA store genetic informationRNA “translate” from DNA to protein
Nucleic acid monomers (nitrogen-containing “base”+ sugar + phosphate) and polymers (polynucleotide, example: DNA, RNA)
How does DNA store information?
RNA “translates” information stored in DNA into a protein that
can actually do something
(enzyme, structural scaffold, etc)
Chemical Nature of DNA: good for storing genetic information
DNA stores information well: polyanionic - prevent folding,
therefore structure not changed by encoded information (imagine if the property of the message you wrote on paper changed the physical properties of the paper/info)
easy to copy because of double helix with base pairing
(like shaking hands) stable
O
O
O
O
PO
O
H
PO
PO
OO
N
N
N
N
N
O
N
N
N
O
O
O
N
ON
O
O
P
O N
O
N
O
O N
O
P
O
N
X
X
X
N
N
O
O
O
N
O
N
O
O
O
N
O
O
O
P
N
O
O
O
N
N
N
O
N
N
H
H
H
H
H
H
PO
H
H
H
H
H
HH
O
N
NN
N
O N
O
OX
O
O
PO
O
H
H
O O
R
R
-
-
-
-
sugar
-
-
T/U
A
CG
A
T/U
-
-
nucleobase pairs
R
R
R
C
chargedphosphodiesterlinkages
Repeating charge does not fold
G
Chemical Nature of Protein: good for building structures and catalyzing chemical reactions
Proteins are made of 20 amino acids, offering many different chemical functionalities (positive and negative charges, hydrophobic, base, thiol)
Therefore proteins can fold into many shapes, and their physical propeties (function) can change dramatically
R
H
R
HR
H
R
H O
N
H
O
N
H
O
N
H
O
N
H
NN
NN
HO
HO
HO
HO R
H
R
HR
H
R
H
R2 R3R1
..
.. ..
R 5 R 6R 4
δ+
..
direction of polypeptide chain
direction of polypeptide chain
Hydrogen bonds holding strands togetherR = aminoacids
δ- δ+δ- δ+
δ- δ+δ-
δ+δ- δ+
δ- δ+δ- δ+
δ-
Repeating dipole can fold = conformation
Amino acids contain chemical functionalitythat are primarily responsible for catalysis
Step back and wonder
Why are there 4 nucleotides in DNAWhy those particular 4 nucleotides?
Why 20 amino acids?Why those particular 20 amino acids?
Why is there RNA?Why does RNA use AGCU and DNA use AGCT?
Does life have to use DNA, RNA and protein?