Transcript Chapters 4+5 - AP Biology 2012-2013

Carbon and macromolecules
Why is carbon unique?
 Carbon is the basis of all life
 Organic chemistry – the study of carbon reactions
 Able to bind on four sides
 Basis of every molecule in your body
Key terms
 Hydrocarbons – molecules of
only carbons and hydrogens
 Carbon skeletons – can come in
many shapes as seen to the right
 Organic molecules – 4 building
blocks of life
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Protein
Nucleic acid
Lipids
carbohydrates
 Polymer – long chain of similar
pieces
 Monomer – a building block of a
polymer
Functional groups
 These groups are added
to hydrocarbon changes
 Leads to carbon
structures have special
functions
How do we build/destroy covalent
bonds?
 Dehydration synthesis –
remove a hydrogen on
one side and an alcohol
on the other to make
water and join the
structures
 Hydrolysis – water splits
and divides a chain
Organic Molecule 1 - Carbohydrates
 Carbohydrates are sugars
 Their basic subunit is a
monosaccharide
 With carbs we can
produce ATP for energy,
or build structures
 Found in cereals, breads,
pastas, grains, fruits, and
veggies
How do you build a carb?
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Saccharide = sugar
Mono = one
Di = two
Poly = many
A carbohydrate is a
polysaccharide
 This means it is made of
chain of
monosaccharides
attached together
How do you build a carb?
 Rembember dehydration
synthesis?
 Dehydration = removal
of water
 Synthesis = building/
creation
How do you build a carb?
 You continue to add
monosaccharides one at a
time
 The bonds between each
sugar is called a glycosidic
linkage
 That linkage is a strong
covalent bond linking the
sugars together
 What functional group
leads to the formation of a
glycosidic bond?
How can you split a sugar?
 The opposite!
 Hydrolysis
 Hydro = water
 Lysis = to split/cut
Storage Polysaccharides
Starch
Glycogen
 Sugar storage in animals
 Sugar storage in animals
 Sugar is primarily made in
 Lasts about a day
daylight and converted to
starch
 In times of darkness plants
can break down starch by
hydrolysis for energy
 Stores in the liver and
muscles
Structural Polysaccharides
Cellulose
Chitin
 Makes up the cell walls of
 Makes the shells of
plants
 Very tough and protective
 Supports plants so they may
grow upwards
 Impossible for humans to
digest
arthropods
 Insects
 Spiders
 Crabs
 Shrimps
 Builds the cell walls for fungi
Lipids
 Subunit – 3 fatty acids +
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glycerol
LONG TERM energy
storage
Make up the plasma
membrane
Insulate us
Pad our organs
Almost all lipids are
nonpolar
Glycerol
 3 carbon chain
 Each carbon has a
hydroxyl group
 Binds to fatty acids
through dehydration
synthesis
Fatty Acid
 Long hydrocarbon chain
 Ends in a _______ group
 That group is what
allows the acid to bind to
the glycerol
Lipids
Fats
Oils
 Found in animals
 Found in plants
 Solid at room temperature
 Liquid at room temperature
 Saturated fat
 No double bond
 Straight lines
 Stack and clog
 Unsaturated fat
 Double bond
 Kinked
 Don’t stack neatly-don’t clog
Saturated VS Unsaturated
 The double bond causes
a bend
 This bend doesn’t allow
the fats to compact and
stack
 This prevents total clogs
in arteries
Phospholipids
 Only two fatty acids
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instead of three
The third hydroxy group
on the glycerol attaches to
a phosphate
This creates a POLAR
region at the head of the
lipid
The rest of the tail remains
nonpolar
Thus the head is attracted
to water and the tail avoids
it
Phospholipids
 Make up the plasma
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membranes of our cells
Keep some things in and
others out
This is done via polarity
Most nonpolar objects
can come in without
issue
Polar objects and larger
objects need “help”
Steroids
 STEROIDS ARE LIPIDS
 I KNOW – THAT
SOUNDS CRAZY
 SERIOUSLY – THEY ARE
LIPIDS, WE WILL TALK
ABOUT THIS LATER
 I could totally take him…
Proteins
 Made of chains of amino
acids
 Put together by
ribosomes
 The order for amino
acids comes from DNA
 Made of amino acids
 Components of an amino
acid
 Amino group
 Carboxyl group
 Hydrogen
 R group
 R Group – side chain
 The side chain
determines which
amino acid you will have
Proteins
Proteins
 Formed by dehydration
synthesis
 The bond between
amino acids is called a
PEPTIDE BOND
Oh what the junk is this junk
 Proteins have four levels of
organization
1. Primary – this is the
order of amino acids
given by DNA/RNA
2. Secondary – how
hydrogen bonds interact
3. Tertiary – interactions of
the side chains
1.
2.
3.
Hydrophobic
interaction
Disulfide bridges
Ionic bond
What can break a protein?
 Denaturation – the unraveling or breaking of a protein
 Nonpolar solution
 Heat
 pH
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Stomach acid
sepsis
What do proteins do?
 EVERYTHING
 Amino acids  proteins  enzymes
 Enzymes – do everything in a cell
 Catalyst – speed reactions
 Anabolism – put molecules together
 Catabolism – rip molecules apart
 Receptors – signal the cell to respond to changes like
temperature, food, bacteria etc
Receptors
What is new with enzymes?
 http://cosmiclog.msnbc.msn.com/_news/2011/09/16/7
802623-gamers-solve-molecular-puzzle-that-baffledscientists
Nucleic Acid
 DNA – code for EVERY protein
 In humans we have 46 strands of chromosomes in each
cell
 23 pairs – 23 from mom/ 23 from dad
 RNA – Code for one protein
 Is a copy of a segment of one strand of DNA
 ATP – chemical energy – made in mitochondria
Subunit
 Nucleotide
 Phosphate group
 Nitrogen base
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Adenine binds with
thymine in DNA
Adenine binds with uracil
in RNA
Guanine binds with
cytosine
 Sugar
 Deoxyribose in DNA
 Ribose in RNA
DNA
 mRNA – messenger RNA
- made as a copy of DNA
 rRNA – ribosome RNA –
attaches amino acids
together – forms peptide
bonds
 tRNA – transfer RNA –
brings amino acids to the
mRNA and rRNA
Compare
DNA
RNA
 Double stranded
 Single stranded
 1 type
 3 types
 Code for all protein
 Code for ONE protein
 Contains thymine
 Contains uracil
 Contains deoxyribose sugar
 Contains ribose sugar
 Found only in nucleus
 Found in cytoplasm and RER
 Only get one of
 Can make copies of
ATP
 The chemical form of
energy used in all
organisms
 Stores energy in the
bond between the 2nd
and 3rd phosphates
 Everyone that has ever
lived and will live dies
when they fail to
produce this
ATP
 It is a charged batter
when it has 3 phosphates
 When it has lost a
phosphate it has spent
its energy and needs
recharged like a battery
 Recharging it takes sugar
and oxygen