AP Biology
ANNOUNCEMENTS UNIT 3 Ecology Exam Average:
Summa Cum Laude:
Magna Cum Laude:
Mastered with a 80% or above:
70%
Raymond
Tevin
Jonathon, Markell, Justin, Roslynn, Lavel, Matthew`
AP Biology
Carbohydrates Structure / monomer
monosaccharide
Function energy raw materials energy storage structural compounds
Examples glucose, starch, cellulose, glycogen
glycosidic bond
AP Biology 2006-2007
Lipidslong term energy storage
concentrated energy
AP Biology
Lipids Lipids are composed of C, H, O
long hydrocarbon chains (H-C)
“Family groups” fats phospholipids steroids
Do not form polymers big molecules made of smaller subunits not a continuing chain
AP Biology
Fats Structure:
glycerol (3C alcohol) + fatty acid fatty acid =
long HC “tail” with carboxyl (COOH) group “head”
dehydration synthesis
H2O
enzyme
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Building Fats Triglyceride
3 fatty acids linked to glycerol ester linkage = between OH & COOH
hydroxyl carboxyl
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Dehydration synthesis
dehydration synthesis
H2O
H2O
H2O
H2O
enzyme
enzyme
enzyme
AP Biology
Fats store energy Long HC chain
polar or non-polar? hydrophilic or hydrophobic?
Function: energy storage
concentrated all H-C!
2x carbohydrates cushion organs insulates body
think whale blubber!
Why do humanslike fatty foods?
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Saturated fats All C bonded to H MORE HYDROGENS!
long, straight chain most animal fats solid at room temp.
contributes to cardiovascular disease (atherosclerosis) = plaque deposits
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Unsaturated fats C=C double bonds in
the fatty acids plant & fish fats vegetable oils liquid at room temperature
the kinks made by doublebonded C prevent the molecules from packing tightly together
mono-unsaturated?poly-unsaturated?
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Saturated vs. unsaturatedsaturated unsaturated
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Phospholipids Structure:
glycerol + 2 fatty acids + PO4
PO4 = negatively charged
It’s just like apenguin…
A head at one end& a tail
at the other!
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Phospholipids Hydrophobic or hydrophilic?
fatty acid tails = PO4 head = split “personality”
interaction with H2O is complex & very important!
“repelled by water”
“attracted to water”
Come here,No, go away!Come here,
No, go away!
hydrophobic
hydrophillic
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Phospholipids in water Hydrophilic heads “attracted” to H2O
Hydrophobic tails “hide” from H2O
bilayer
water
water
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Why is this important? Phospholipids create a barrier in water
define outside vs. inside they make cell membranes!
Tell themabout soap!
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Steroids Structure:
4 fused C rings + ?? different steroids created by attaching different
functional groups to rings different structure creates different function
examples: cholesterol, sex hormones
cholesterol
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Cholesterol Important cell component
animal cell membranes precursor of all other steroids
including vertebrate sex hormones high levels in blood may contribute to
cardiovascular disease
AP Biology
D.N.AObjective: Describe the four levels of protein conformation and relate them to reversable and nonreversable denaturation
Label the definition with the correct macromolecule
A. Proteins
B. Carbohydrates
C. Nucleic acids
D. Lipids
E. Steroids
1. Synthesized at the ribosome
2. Includes glycogen, chitin, cellulose, and glucose
3. Used for insulation and buoyancy in marine Arctic animals
4. Used to carry the genetic code
AP Biology 2008-2009
ProteinsMultipurpose
molecules
AP Biology
Proteins Most structurally & functionally diverse group Function: involved in almost everything
enzymes structure (keratin, collagen) carriers & transport (hemoglobin, aquaporin) cell communication
signals (insulin & other hormones) receptors
defense (antibodies)
AP Biology
Proteins Structure
monomer = amino acids 20 different amino acids
growthhormones
H2O
AP Biology
Amino acids Structure
central carbon amino group carboxyl group (acid) R group (side chain)
variable group different for each amino acid confers unique chemical
properties to each amino acid like 20 different letters of an
alphabet can make many words (proteins)
—N—H
HC—OH
||O
R
|—C—
|
H
Oh, I get it!amino = NH2 acid = COOH
AP Biology
Building proteins Peptide bonds
covalent bond between NH2 (amine) of one amino acid & COOH (carboxyl) of another
C–N bond
peptidebond
dehydration synthesisH2O
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Protein structure & function
hemoglobin
Function depends on structure 3-D structure
twisted, folded, coiled into unique shape
collagen
pepsin
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Primary (1°) structure Order of amino acids in chain
amino acid sequence determined by gene (DNA)
slight change in amino acid sequence can affect protein’s structure & its function even just one amino acid change
can make all the difference!
lysozyme: enzyme in tears & mucus that kills bacteria
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Sickle cell anemia
I’mhydrophilic!
But I’mhydrophobic!
Just 1out of 146
amino acids!
AP Biology
Secondary (2°) structure “Local folding”
folding along short sections of polypeptide interactions between
adjacent amino acids H bonds
weak bonds between R groups
forms sections of 3-D structure -helix -pleated sheet
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Tertiary (3°) structure “Whole molecule folding”
interactions between distant amino acids hydrophobic interactions
cytoplasm is water-based
nonpolar amino acids cluster away from water
H bonds & ionic bonds disulfide bridges
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Quaternary (4°) structure More than one polypeptide chain bonded
together only then does polypeptide become
functional protein hydrophobic interactions
collagen = skin & tendons hemoglobin
AP Biology
Protein structure (review)
amino acid sequence
peptide bonds
1°
determinedby DNA R groups
H bonds
R groupshydrophobic interactions
(H & ionic bonds)
3°multiple
polypeptideshydrophobic interactions
4°
2°
AP Biology
Protein denaturation Unfolding a protein
temperature pH salinity
alter 2° & 3° structure alter 3-D shape
destroys functionality some proteins can return to their functional shape
after denaturation, many cannot
In Biology,size doesn’t matter,
SHAPE matters!
AP Biology
CREATE A CONCEPT MAP
In a group of 4, each person is responsible for creating a concept map for one of the macromolecules
Carbohydrates Lipids Proteins Nucleic Acids
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AP Biology
Nucleic AcidsInformation
storage
AP Biologyproteinsproteins
DNADNA
Nucleic Acids Function:
genetic material stores information
genesblueprint for building proteins
DNA RNA proteins
transfers informationblueprint for new cellsblueprint for next generation
AP Biology
AA
A
A
TC
G
CG
TG
C
T
AP Biology
Nucleic Acids Examples:
RNA (ribonucleic acid) single helix
DNA (deoxyribonucleic acid) double helix
Structure: monomers = nucleotides
RNADNA
AP Biology
Nucleotides 3 parts
nitrogen base (C-N ring) pentose sugar (5C)
ribose in RNA deoxyribose in DNA
phosphate (PO4) group
Nitrogen baseI’m the
A,T,C,G or Upart!
AP Biology
Types of nucleotides 2 types of nucleotides
different nitrogen bases purines
double ring N base adenine (A) guanine (G)
pyrimidines single ring N base cytosine (C) thymine (T) uracil (U)
Purine = AGPure silver!
AP Biology
Nucleic polymer Backbone
sugar to PO4 bond
N bases hang off the sugar-phosphate backbone
AP Biology
Pairing of nucleotides Nucleotides bond between
DNA strands H bonds purine :: pyrimidine A :: T
2 H bonds G :: C
3 H bonds
Matching bases?Why is this important?
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DNA molecule Double helix
H bonds between bases join the 2 strands A :: T C :: G
H bonds?Why is this important?
AP Biology
Copying DNA Replication
2 strands of DNA helix are complementary have one, can build other have one, can rebuild the
whole
Matching halves?Why is this
a good system?
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When does a cell copy DNA? When in the life of a cell does DNA have
to be copied? cell reproduction
mitosis gamete production
meiosis
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DNA replication“It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.”
James WatsonFrancis Crick
1953
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Watson and Crick … and others…1953 | 1962
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Maurice Wilkins… and…1953 | 1962
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Rosalind Franklin (1920-1958)
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Interesting note… Ratio of A-T::G-C
affects stability of DNA molecule 2 H bonds vs. 3 H bonds biotech procedures
more G-C = need higher T° to separate strands
high T° organisms many G-C
parasites many A-T (don’t know why)
AP Biology
Another interesting note… ATP
Adenosine triphosphate
++
modified nucleotide adenine (AMP) + Pi + Pi