Transcript Molecules of Life

Molecules of Life
Organic Molecules
Biological Molecules
Organic Molecules
• Why is this important?
• Cells are mostly water and carbon-based
molecules
• Carbon has a valence of 4 so it will form a
tremendous variety of large, complex and
diverse molecules
• Large variety of molecules = diversity of life
Unity in Diversity
• All life is composed of carbon compounds
(Unity)
• Diversity of life is due to various ways
carbon can be assembled
• Organic chemistry = study of the
compounds formed by carbon
Organic Chemistry
• The four valence electrons in carbon
enable it to be bonded in four different
directions
• Usually forms COVALENT bonds with
Hydrogen
• Often oxygen, nitrogen
• Four most common elements are: CHON
1
1
6+
1
1
Hydrocarbons
ISOMER
Ethane
Functional group
Ethanol
• Functional groups –
•
•
•
•
groups of atoms that have
properties/role on the
molecule
OH – hydroxide (polar)
NH2 – amino (polar)
COOH – carboxyl (polar)
CH3 – methyl (nonpolar)
Organic Chemistry
• Biochemistry - chemistry of living things
• Functional groups change the chemical
properties/function of a molecule
• The great diversity of life is caused by only
a few molecules with different
arrangements of functional groups
The rearrangement of FUNCTIONAL GROUPS
on a molecule causes major changes in the
molecule’s function
Biochemistry
• Four basic carbon molecules important to
all living things:
• Carbohydrates
• Lipids
•Proteins
• Nucleic acids
Biochemistry
• The four basic molecules are long chains
of smaller molecules linked together
• A train formed by various types of cars
Biochemistry
• Smaller molecules are called
MONOMERS
• Long chains are called………
•POLYMERS
• Polymers are large molecules
• MACROMOLECULES – large polymer
What You Have to Know:
• For each of the 4 types of molecules:
1. The types and names of the monomers
2. The role of each molecule in life
How Are Organic Compounds
Formed?
• Monomers = smaller functional molecules
that can be linked together
• Macromolecule = ‘large molecule’
• Polymers = macromolecules formed by
linking monomers together
Polymerization
• Many monomers are linked together
to form macromolecules
• Dehydration synthesis
How Are Organic Compounds
Formed?
• Dehydration synthesis
• OH- combines with OHfrom adjacent monomer
• OH + OH = HOH + O
• HOH = H2O
• All four compounds
important to life are formed
by dehydration synthesis
Macromolecules – dehydration synthesis
Monomers/Polymers
• Hydrolysis - breaking down polymers into
monomers
4 Types of Macromolecules
Carbohydrates
Lipids
Proteins
Nucleic acids
Carbohydrates
• Carbon, hydrogen, oxygen
• C(n)H2O
– C6H12O6 – glucose
– C6H12O6 - fructose
– C5H10O5 - ribose
– C12H22O11 – sucrose
Carbohydrates
• Sugars; three types:
– Monosaccharides ‘one sugar’
– Disaccharides ‘two sugar’
– Oligosaccharides ‘few sugar’
– Polysaccharides ‘many sugar’
Carbohydrates – Monomers
• Simple sugars
• Monosaccharides –
‘one sweet’
– Glucose, fructose,
ribose, deoxyribose,
galactose
Carbohydrates: Monomers
• Glucose; #1 sugar, most used sugar for energy
in most organisms
• Fructose; very sweet (fruits)
• Most monosaccharides are
used as a source of
energy
– Ribose and deoxyribose
form part of the structure
of DNA, RNA
Di-saccharides
• Di = ‘two’
• Two monosaccharides joined together by
DEHYDRATION SYNTHESIS
• Energy storage
• Glucose + glucose = maltose; germinating
seeds, malt in beer
• Glucose + fructose = sucrose; table sugar
• Galactose + glucose = lactose; milk
Oligosaccharides
• ‘few’
• Short chains of monosaccharides on the
outside of the cell membrane
• Cell-to-cell communication, identification
Polysaccharides
•
•
•
•
•
‘Poly’ = many
Long chain of monosaccharides
Starch
Glycogen
Cellulose
Polysaccharides
• Examples:
– _______ – used to make cell walls of plants;
indigestible without bacteria in gut; fiber
– ______ - cell walls of fungi; cells of arthropods
– ______ – stored glucose in plants
– _______ – stored glucose in animals
Check Point
• What is the primary function of carbs?
• Plant cell walls are made of ____
• What is the process by which
macromolecules are assembled _____
• By what process are macromolecules
broken down? _____
• Name 2 monosaccharides
• What is a hydrocarbon? _____
Types of Macromolecules
Carbohydrates
Lipids
Proteins
Nucleic acids
Lipids
• Three types of lipids:
–Triglycerides
–Phospholipids
–Steroids
Triglycerides
•
•
•
•
•
Fats, Oils, Waxes
Insoluble in water – nonpolar
Glycerol + three fatty acids
Dehydration synthesis
Lots of C-H bonds (energy)
Triglycerides
•
2 types of triglycerides:
– Saturated
– Unsaturated
• Saturated fats
have no double
bonds; are full
(saturated) with
hydrogen
– Arteriosclerosis
Saturated
fatty acid
Saturated
fatty
Unsaturated fatty acid
Unsaturated fatty acid
acids
Types of Fats
•
•
•
•
•
•
Saturated
No double bonds
Saturated w/ H
Solids @ (200)
Animal fats
Bacon grease,
lard, butter
•
•
•
•
•
•
Unsaturated
Double bond(s)
Unsaturated
Liquids @ (200)
Plant fats (oil)
Corn, peanut, olive
oils
Fats: Functions
• Store energy
– More energy in fats than in carbs; birds eat
sunflower seeds first
• Padding (eye, other organs)
• Insulation (keep you warmer; seals, whales)
• Waterproofing - oils
Lipids - Phospholipids
• Triglyceride - One of the fatty
acid ‘tails’ is replaced with a
phosphate group
• Phospho – lipid
• Major component of cell
membrane
Fatty acids
Steroids
• Cholesterol – basic molecule used in cell
membrane; also used to make other
steroids (estrogen and testosterone)
Lipids: Steroids
• Sex hormones:
• Testosterone; male
• Estrogen; female
Lipids: Steroids
• Anabolic steroids = artificially created
testosterone
• Mimics male hormone
• Increased muscle mass
• Decreased sex drive, infertility
• Heart, liver problems
Lipids - Steroids
• Anabolic steroids – synthetic variations of
testosterone
• Builds muscle and bone mass during
puberty; maintains male characteristics
• Used in 1950’s to treat anemia and muscle
diseases
• Abused by athletes; linked to liver damage,
cardiovascular, mood swings
Steroids
• Insoluble in water (nonpolar)
• Very different from other lipids in structure
• 4 fused carbon rings with various
FUNCTIONAL GROUPS
Proteins
• Composed of AMINO ACIDS
(monomers)
• 20 different amino acids
• Differences between the
20 amino acids are caused
by different R (side)
groups
Different amino acids caused by different side groups
Amino Acids
• Amino acids are linked together by
dehydration synthesis
• Bonds formed between
amino acids are
BONDS
• Long chain of peptides =
polypeptide
PEPTIDE
• Amino acids are linked together in a specific
sequence
• Conformational shape specific 3d shape of a
protein
• If the sequence gets messed up, the protein
may not function. May be fatal or only cause
health problems
• Denaturation – change in the conformational
shape keeping the protein from functioning
Conformational Shape
• H bonding helps determine shape
• Breaking the H bond changes the shape of
the protein – (denaturation)
– Heat - cooking changes the shape of
proteins; turn brown; eggs turn white
– Poisons – chemicals change shape by
interrupting bonds (acids, bases,
acetone)
Proteins - Functions
1.
Structure – feathers, hair, muscle, nail, horn
2. Enzymes – speed up reactions
3. Hormones – chemical messengers
4. Carriers – hemoglobin carries oxygen to
cells
Enzymes
• Speed up chemical reactions without
being changed
• Reduce activation energy
Nucleic Acids
• Monomers – NUCLEOTIDES
• Nucleotides:
– A simple sugar
– A phosphate group
– A NITROGENOUS BASE
H bonding
Adenine
always
bonds with
Thymine
Cytosine
always
bonds with
guanine
A-T
C-G
ATTC C G CATG G GTCTTTT
TAA G G C G TA C C CA G AAAA
DNA sequence = “genetic code”
TACCATACTTTCGGCTACTTTTGGG
ATGGTATGATATCCGATGATAACCC
TACCATACTATAGGCTACTATTGGG
If A-T and C-G, what is the
complimentary strand?
Similarities in DNA sequences indicates
close evolutionary relationship